Conservation assessment of Glyphis sp. A (speartooth shark ... · Version 2 Conservation assessment...

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Conservation assessment of Glyphis sp. A (speartooth shark), Glyphis sp. C

(northern river shark), Pristis microdon (freshwater sawfish) and Pristis zijsron

(green sawfish)

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Final Report J. D. Stevens, R. D. Pillans, and J. Salini CSIRO Marine Research Client: Department of the Environment and Heritage June 2005

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ISBN: 9780642553467 The views and opinions expressed in this publication are those of the authors and do not necessarily reflect those of the Australian Government or the Minister for the Environment and Heritage.

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Conservation assessment of Glyphis sp. A (speartooth shark), Glyphis sp. C (northern river shark), Pristis microdon (freshwater sawfish) and Pristis zijsron (green sawfish)

Introduction In November 2004, CSIRO Marine Research (CMR) started a six-month project on Glyphis and Pristis species. The project, funded under the Commonwealth Government’s Department of the Environment and Heritage (DEH), is collaborative with the Fisheries Department of Western Australia, the Northern Fisheries Centre (QDPI) and the Northern Territory Fisheries (NTDBIRD). Background Members of the genus Glyphis and Pristis are amongst the most threatened elasmobranchs worldwide and there is growing national and international concern over their status. There is still considerable uncertainty over the taxonomy of the genus Glyphis (Family Carcharhinidae) that is represented by four to six species in the Indo-West Pacific. All species are considered to be endangered throughout their distribution and some are feared extinct within South East Asia. Within northern Australia, there are two species both of which appear to have extremely limited habitat preferences and despite intensive surveys fewer than 20 specimens had been recorded from five rivers prior to 2003. In Australia, Glyphis have only been recorded from freshwater and weakly saline habitats and it is uncertain whether they are limited to these areas or are also found in marine environments. Glyphis sp. A is listed as Critically Endangered by both the IUCN (Cavanagh et al., 2003) and 1999 Commonwealth Environmental Protection and Biodiversity Conservation (EPBC) Act while Glyphis sp. C is listed as Critically Endangered by the IUCN and Endangered by the 1999 EPBC Act. Sawfish (Family Pristidae; Genus Pristis) are represented by about seven species worldwide with four species found in Australia. Sawfish are particularly vulnerable to capture in gill net and trawl fisheries due to their heavily toothed rostrum. While there are few quantitative data, the numbers of sawfish appear to have declined drastically along the east coast of Australia with sawfish now virtually extinct in NSW and South East Queensland. Measuring declines elsewhere is hindered by a lack of records and poor species identification. Both Pristis microdon and Pristis zijsron are found throughout northern Australia; however their abundance and specific habitat requirements are unknown. From data collected to date, it appears that juvenile P. microdon appear to be mainly confined to freshwater environments. Pristis microdon is listed by the IUCN as Critically Endangered in SE Asia and as Vulnerable under the EPBC Act. Pristis zijsron is listed as Endangered by the IUCN and has recently been nominated as Vulnerable under the EPBC Act. International concern for Pristis and Glyphis has grown over the last 10 years and the need for conservation action has been highlighted by international organisations such as the IUCN’s Red List of Threatened Species and FAO’s International Plan of Action for the Conservation and Management of Sharks (IPOA-Sharks). The combination of restricted habitats, extreme vulnerability to entanglement in nets, and low productivity make them very susceptible to overfishing and to the effects of coastal development. In Australia, conservation and management decisions are severely hampered by the lack of data on the biology, distribution and abundance of these animals due to their rarity, and to confusion over their identity.

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Objectives 1. To determine the conservation status, distribution, abundance, range of and threats to Glyphis sp. A, Glyphis sp. C, Pristis microdon and Pristis zijsron under the EPBC Act 2. To carry out a field-based study on the movement, abundance and habitat utilisation of Glyphis sp. A in the Adelaide River, NT. Format of the report The report comprises three parts. Part 1 comprises the conservation assessments of Glyphis sp. A, Glyphis sp. C, Pristis microdon and Pristis zijsron that are presented in the DEH data sheets. Part 2 is the field-based study on movement, abundance and habitat utilisation of Glyphis sp. A that was carried out in the Adelaide River, Northern Territory. Part 3 is the draft report on sawfish catch data in northern Australia (information from which is included in the data sheets).

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Department of the Environment and Heritage

Data Sheet Important notes:

• For all facts and all information presented – identify your references/information sources, document reasons and supportive data. Indicate the quality of facts/information, for example was it based on research or anecdotal data; on observed data or estimated or inferred from data; or suspected to be the case.

• Personal communications - Identify data/opinions based on personal communications (including your own). These need to be supported by permission slips (available from the Department) so that opinions can be cited on the Department’s website if needed.

• Confidential material – Identify confidential material and explain the sensitivity. • Tables – Can be included at the end of this document or prepared as separate electronic documents.

Refer to tables in the relevant area of the text. • Species - applies to the entity nominated under the Act, either species and subspecies • Population – refers to populations within a species or total population numbers for a species. • Cross-reference relevant areas of the data sheet where needed. • Definitions – If more guidance on definitions is needed, see IUCN Guidelines at

http://www.iucn.org/themes/ssc/redlists/RedListGuidelines.pdf

Section 1 – Conservation Assessment Information required for assessing species nominated as threatened under the EPBC Act. Answer all parts, indicating when there is no information available. Taxonomy

1. What are the currently accepted scientific and common name/s for the species? Note any other scientific names that have been recently used

Scientific name Common name Glyphis sp. A Bizant River shark, Queensland river shark, spear tooth

shark

2. Is this species conventionally accepted? If not, explain why. Is there any controversy on the taxonomy? Yes this species is conventionally accepted (Last and Stevens, 1994; Compagno and Niem, 1998), however there is still some uncertainty about the relationship between Glyphis sp. A and Glyphis glyphis (Müller and Henle, 1839). Glyphis sp. A and a similar species collected in Papua New Guinea may be synonymous with G. glyphis (LJVC Compagno, Shark Research Center, Box 61, Cape Town 8000, personal communication), however G. glyphis was described from only one spe`cimen without locality.

3. Describe any cross-breeding with other species in the wild, indicating how frequently and where this occurs There is no evidence of cross breeding between the two members of this genus found in Australia (Glyphis sp. A and Glyphis sp. C). Legal status 4. What is the species’ current conservation status under Australian and State/Territory Government legislation? Glyphis sp. A is listed as Critically endangered under the Environment Protection Biodiversity and Conservation Act 1999(EPBC Act 1999). This species has been listed since 2001.

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Glyphis sp. A is not listed under State Government legislation in the three states in which it occurs (ie Northern Territory and Queensland). Glyphis sp. A is listed as critically endangered by the IUCN Red List 2003. Description 5. Give a brief description of the species’: appearance, including size and/or weight, and sex and age variation if appropriate; social structure and dispersion (e.g. solitary/clumped/flocks)

Glyphis sp. A belongs to the family Carcharhinidae. They are medium-sized whaler sharks, greyish on the dorsal surface and white below, without a distinctive color pattern and no interdorsal ridge. The second dorsal fin is between half to three fifths the height of first dorsal fin and its origin is slightly anterior to the anal fin origin. They have short and broadly rounded snouts, and erect, broadly triangular, serrated upper teeth, the lower teeth are long and slender with the cusps smooth basally but with serrated, spear-like expanded tips (Last & Stevens, 1994; Compagno and Niem, 1998). Glyphis sp. A has more vertebrae (198 - 217) than Glyphis sp. C (142 - 151). Glyphis sp. A also has black or dusky tips on the venrtal surface of the pectoral fins which are lacking in Glyphis sp C.

Maximum recorded size is 175 cm TL for females and 157 cm TL for males. Both of these animals and others of similar size were not sexually mature. Based on data from other Carcharhinids, maximum size is therefore likely to be well over 200 cm TL.

Although sexual segregation is common in elasmobranchs, there is no evidence of this occuring in rivers and estuaries.

6. Identify major studies on the species

Apart from research conducted as part of this assessment, there has been no targeted research into the biology and ecology of this species. Pogonoski et al. (2002) reviewed the status of Glyphis sp. A. Prior to 2003 fewer than 20 specimens of Glyphis sp. A were recorded from northern Australia. Glyphis sp. A was first recorded from the Bizant River in Queensland in 1982 and subsequently recorded from the South and West Alligator Rivers in the Northern Territory (Larson, 2000). A Natural Heritage Trust (NHT) funded survey of freshwater and estuarine elasmobranchs in northern Australia, which sampled 147 sites in 39 rivers and creeks did not record any specimens of Glyphis sp. A.

A total of 108 individuals of Glyphis sp. A have been recorded from northern Australia. The data associated with these records represent the only data on this species, and are presented in Appendix 1.6.1. International context (for species that are distributed both inside and outside Australia’s jurisdiction) 7. Describe the species’ global distribution Glyphis sp. A is only recorded from northern Australia, however this species may be synonymous with Glyphis glyphis which was described from a single specimen from unknown location. 8. Give an overview of the global population’s size, trends, threats and security of the species outside Australia Although Glyphis sp. A has not be identified outside Australia, members of this genus have been recorded from South East Asia (India, Pakistan, Borneo and New Guinea) and are either presumed extinct or very uncommon in these areas. The Ganges river shark, Glyphis gangeticus is known from Ganges and Hooghly Rivers, India and possibly from Karachi in Pakistan. This species in known from only three museum species and despite intensive surveys in the past 10 years only one additional specimen and two sets of jaws have been collected. The Borneo River shark, Glyphis sp. B was previously known from one specimen in a museum in Vienna that was collected from a river in Borneo over 100 years ago. This species was assumed to be extinct until it was “rediscovered” in the Kinabatangan River in northern Borneo in 1996. 9. Explain the relationship between the Australian population and the global population, including:

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a. What percentage of the global population occurs in Australia; b. Is the Australian population distinct, geographically separate or does part or all of the population move in/out

of Australia’s jurisdiction (give an overview; details in Movements section); c. Do global threats affect the Australian population?

N/A National context Distribution 10. Describe the species’ distribution in Australia and, if available, attach a map Glyphis sp. A has to date only been found in rivers and estuaries within the Northern Territory and Queensland (Figure 1.10.1). Photographs of one specimen captured in the Ord River in Western Australia resemble to be this species, however, the specimen was released and this record cannot be verified (R. Pillans, personal observation). Within the Northern Territory, Glyphis sp. A have been recorded from the lower reaches (salinity between 3 and 25.8 PPT)of the Adelaide River, South, East and West Alligator Rivers and Murganella Creek. Within Queensland, Glyphis sp. A have been recorded from the lower reaches (salinity between 0.8 and 28 PPT) of the Wenlock and Ducie Rivers and Port Musgrave (the estuarine system of these two rivers) as well as the Bizant River. There are also unverified reports of Glyphis sp. A in the Normanby River in 1983, Hey River in 1981 and Embley River in 1985 (Rod Garrett and Geoff McPherson, QDPIF, personal communication, 2005). The identification of these animals is currently being investigated by QDPIF and will be available in the near future.

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Figure 1.10.1. Distribution of Glyphis sp. A in Australia based on all recorded specimens whose identification has been verified. Unverified reports are not included in this map. 11. What is the extent of occurrence (in km2) for the species (described in Attachment A); explain how it was calculated and datasets used

a. What is the current extent of occurrence? b. What data is there to indicate past declines in extent of occurrence (if available, include data that indicates

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the percentage decline over the past 10 years or 3 generations whichever is longer)? c. What data is there to indicate future changes in extent of occurrence (if available, include data that indicates

the percentage decline over 10 years or 3 generations whichever is longer (up to a maximum of 100 years in the future) where the time period is a continuous period that may include a component of the past)?

a. Glyphis sp. A appears to have a limited distribution and are confined to a few highly turbid, tidal rivers and

estuaries in northern Australia. Data on the occurrence of this species is limited to records of individuals in nine rivers and estuaries from Bizant River, Qld, in the East to the Adelaide River, NT, in the West. That Glyphis sp. A has only been found in nine river systems, despite observer programs in commercial fisheries operating in most rivers and estuaries between these rivers (over 3500 km of coastline), as well as observer programs operating in inshore and offshore net and long line fisheries suggests that they have specific habitat requirements and are only restricted to a few river systems. A Natural Heritage Trust (NHT) funded survey of freshwater elasmobranchs surveyed 14 rivers and estuaries between the Bizant River and the Adelaide River and did not record any Glyphis sp. A (Thorburn et al., 2003).

b. The increase in the number of recorded specimens in the past 3 years does not reflect an increase in the

abundance and or distribution of Glyphis sp. A but rather an increased awareness amongst commercial fishers and research organizations which has led to surveys targeting this species primarily in the Adelaide River (see Part 2 of this report) and the Wenlock and Ducie Rivers (Peverell, 2005). Although there is no direct evidence of a decline in the extent of occurrence, that no specimens have been recorded on the east coast of Australia since the discovery of Glyphis in the Bizant and Normanby River in 1982 and 1983, respectively (Rod Garrett and Geoff McPherson, QDPIF, personal communication, 2005) is of concern. Given the high commercial fishing effort that occurred in these rivers systems and adjacent coastline, combined with research surveys occurring in these systems, it is expected that Glyphis sp. A would have been recorded since 1983. Additional surveys are required to determine whether Glyphis sp. A are still found in these rivers, or any other rivers on the east coast of Australia. The disappearance of Glyphis sp. A from these systems would represent a significant reduction in the species distribution.

c. There is no data to suggest that future changes in the extent of occurrence will occur. However, given the

increase in the number of records in the past three years it is anticipated that the distribution of Glyphis sp. A may increase to include additional river systems in Northern Australia. Based on available habitat it is likely that distribution will be extended west of the Adelaide River, rather than east of the Normanby River.

12. What is the area of occupancy (in km2) for the species (described in Attachment A; explain how calculated and datasets that are used)

a. What is the current area of occupancy? b. What data is there to indicate past declines in area of occupancy (if available, include data that indicates the

percentage decline over the past 10 years or 3 generations whichever is longer)? c. What data is there to indicate future changes in area of occupancy (if available, include data that indicates


a. The area of occupancy of Glyphis sp. A is approximately 502 km2. This value was calculated by summing the

area (km2) of each river system/ estuary that Glyphis sp. A has been recorded in (Attachment A). The area of the entire river system from the mouth to the first dry season barrier was assumed to be suitable habitat and was therefore used. Area was calculated using the “draw polygon” feature in ArcView GIS 3.3 and is the sum of area of each river system excluding the Normanby River.

b. To date, Glyphis sp. A have not been recorded outside of rivers and estuaries. This is reflected by the very

small area of occupancy. Given the high commercial fishing effort that occurs both along the coastline and well offshore, it is very surprising that no specimens have been recorded in a marine environment between the Bizant River and the Adelaide River. Scientific observers have been monitoring catches of sharks in both commercial gillnet (Qld and NT) and longline (NT) fisheries operating in these waters have not recorded this species outside of rivers and estuaries. The lack of records marine records suggests that this species may be restricted to rivers and estuaries and as such their area of occupancy is very small.

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c. There is currently no data to suggest that area of occupancy will be reduced in the future. The area of

occupancy is likely to be increased as a result of additional records of this species from rivers and estuaries within their current range.

13. Is the species’ distribution severely fragmented? Why? Severely fragmented refers to the situation in which increased extinction risk to the taxon results from most individuals being found in small and relatively isolated subpopulations (in certain circumstances this may be inferred from habitat information). These small subpopulations may go extinct, with a reduced probability of recolonization. More data is required to determine whether the distribution of Glyphis sp. A is fragmented. Available data suggests that there are three locations where this species occurs and that there are large distances between the locations (Appendix A). These data combined with the lack of specimens from a marine environment (ie no data to suggest movement between rivers) suggests that this species may be comprised of isolated sub populations. Additional data on the distribution of Glyphis sp. A as well population genetic analyses are needed to determine the degree of fragmentation. 14. How many locations do you consider the species occurs in and why? The term 'location' defines a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the species present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a species is affected by more than one threatening event, location should be defined by considering the most serious plausible threat. Based on available data, there are currently three geographically distinct locations in which the species occurs. These are: 1) Van Dieman Gulf drainage, NT, including the Adelaide River, South, East and West Alligator Rivers, and Murganella Creek; 2) Port Musgrave, Qld., including the Wenlock and Ducie Rivers; and 3) The Bizant River and possibly the Normanby River in Princess Charlotte Bay. Glyphis sp. A have been found in all 5 rivers systems that flow into the Van Dieman Gulf, a total area of 322 km2. This region appears to be centre of abundance for this species and is the only place where Glyphis sp. A are known to occur in adjacent river systems. Given the proximity of these rivers (less than 115 km apart), it is not unreasonable to assume to during the wet season; animals would be capable of moving between river systems whilst remaining in turbid water of reduced salinity. The South, East and West Alligator Rivers and Murganella Creek are within Arnhem Land and Kakadu National Park and animals within these systems are therefore not exposed to commercial fishing or any form of habitat modification. Commercial fishing for barramundi (Lates calcarifer) was allowed at the mouth of the Adelaide River but not above and Glyphis sp. A have been recorded in this fishery at the mouth of the Adelaide River during the wet season (Richard Pillans, CSIRO Marine Research, unpublished data). However, recent changes in legislation prevent fishing inside the mouth of the Adelaide River (Northern Territory of Australia Barramundi Fishery Management Plan, February 2005). Glyphis sp. A have only recently been “discovered” in the Ducie and Wenlock rivers, however, commercial fishers operating in this system for more than 20 years claim that this species has always been captured and recorded as bull sharks which are also captured in this system. The total area of this system is approximately 174 km2. Glyphis sp. A have not been recorded in nearby river systems of similar size. Recent surveys of the Mission River (Peverell, 2005) as well ongoing fish surveys in the Embley River for the past 20 years have not recorded this species (Blaber et al., 1989; Steven J. Blaber, personal communication, 2005) suggesting that it is confined to the Wenlock and Ducie Rivers. Commercial gill net fishing targeting barramundi capture Glyphis sp. A in both these rivers and Port Musgrave (Peverell, 2005). That Glyphis sp. A have not been recorded in the Bizant River since 1982 is reason for concern. Additional research surveys are required in this river and adjacent systems to determine whether this species still occurs in these rivers. The small available habitat in the Bizant River (approximately 7 km2), suggests that population size in this system would be much smaller than other systems where Glyphis sp. A is found, and therefore more prone to localised extinction. Habitat 15. Give a brief description of the species’ habitat/s (Details entered in Section 2)

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Data from over 100 individuals indicates that Glyphis sp. A utilise large tropical river systems as their primary habitat. To date, no animals have been captured outisde of rivers and estuaries and no sexually mature animals have been captured. It is also worth noting that unlike bull sharks (Carcharhinus leucas) which are often captured in freshwater billabongs or sections of river isolated from the main tidal stream, no Glyphis sp. A have been recorded from areas outside of tidal rivers and estuaries. Although the majority of specimens are neonates and juveniles (Figure 1.15.1), sub adults between up to 175 cm TL have also been captured. That no sexually mature specimens have been captured suggests that adults are occupying a separate habitat to neonates and subadults, however, despite intensive inshore and offshore gill net fisheries in WA, NT or Qld, no mature specimens have been recorded in a marine environment. Based on data from other euryhaline elasmobrnachs such as the bull shark, it is anticipated that adult Glyphis sp. A live in inshore marine coastal areas.

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Figure 1.15.1. Length frequency of all Glyphis sp. A recorded to date (excluding nine animals recently captured in Port Musgrave, Queensland).

Within Australia, neonate and juvenile bull sharks utilise the low salinity upper reaches of rivers and estuaries as nursery areas and sharks less than 150 cm TL are very uncommon in the upper reaches of rivers and estuaries, while sharks greater than 150 cm TL predominantly occur in marine environments (R. Pillans, unpublished PhD data). Within the Adelaide River, where the most data are available, out of 54 animals, 60% were under 80 cm TL and nearly 20% were over 130 cm TL. Animals between 150 – 175 cm TL made up 5 % of the total (Figure 1.15.2). The number of sharks over 130 cm TL suggests that Glyphis sp. A are more dependent on riverine/estuarine environments for long periods, or spend longer in these environments than bull sharks. The absence of marine records of Glyphis sp. A suggests that riverine/estuarine environments may be important to this species throughout their life and not just as a nursery area.

As noted in Section 10, Glyphis sp. A have been recorded in salinity ranging from 0.8 – 28 PPT. Given the range of salinity it has been recorded in, it is a euryhaline elasmobranch capable of living in and moving between freshwater and seawater. Although it has not been recorded in full strength seawater (35 PPT), from a physiological perspective, 28 PPT is effectively seawater and animals would need to employ similar physiological mechanisms to bull sharks in order to live in both freshwater and seawater. Animals living in salinity nearing freshwater would have to reduce plasma osmolytes (Na, Cl, Mg, Urea and TMOA) but also be able to retain these osmolytes against a concentration gradient favouring the diffusional loss of these ions (see Hazon et al., 2003; Pillans and Franklin, 2004; Pillans et al., 2005). Animals in salinity nearing seawater would need to actively excrete ions via the rectal gland and would need to synthesise urea in the liver in order to maintain their hyperosmotic osmoregulatory strategy. Analysis of blood chemistry from Glyphis sp. A captured across a salinity gradient would provide useful information regarding their osmoregulatory ability.

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Figure 1.15.2. Length frequency of 56 Glyphis sp. A captured in the Adelaide River, Northern Territory.

The small amount of data collected on the physical properties of rivers systems Glyphis sp. A have been captured in indicates a preference for highly turbid, tidally influenced waters with fine muddy substrate. Animals have been captured in temperatures ranging from 27 – 32 º C. Populations 16. What is the species’ total population size in terms of number of mature individuals? Are there other useful measures of population size and what are they? In the absence of figures, terms such as common, abundant, scarce can be of value. There are no available estimates of population size for any river system Glyphis sp. A are found in. 17. Does the species occur in a number of smaller populations? How many? If available, for each population give the locality, numbers and trends in numbers and tenure of land (if available) (include extinct populations). Can these be considered to be subpopulations and why? Subpopulations are defined as geographically or otherwise distinct groups in the population between which there is little demographic or genetic exchange (typically one successful migrant individual or gamete per year or less). This species may occur in different subpopulations, however there is no estimate of their size. 18. What is the population trend for the entire species?

a. What data is there to indicate past decline in size (if available, include data on rate of decline over past 10 years or 3 generations whichever is longer)?

b. What data is there to indicate future changes in size (if available, include data which will indicate the percentage of decline over 10 years or 3 generations whichever in longer (up to a maximum of 100 years in the future) where the time period is a continuous period that may include a component of the past)?

There are insufficient data to demonstrate a population decline. The lack of specimens from Bizant River since 1982, despite recent surveys in this river may reflect a reduction in population size within this river system; however, additional data are required to validate this. 19. Does the species undergo extreme natural fluctuations in population numbers, extent of occurrence or area of

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occupancy? To what extent and why? Extreme fluctuations can be said to occur in a number of taxa when population size or distribution area varies widely, rapidly and frequently, typically with a variation greater than one order of magnitude (i.e. a tenfold increase or decrease). Given the stable life history of elasmobranchs (ie long lived, slow growing, low fecundity, production of a small number of well developed you) they are not generally prone to large natural fluctuations in population numbers. 20. What is the generation length and how it is calculated? Generation length is the average age of parents of the current cohort (i.e. newborn individuals in the population). Generation length therefore reflects the turnover rate of breeding individuals in a population. Generation length is greater than the age at first breeding and less than the age of the oldest breeding individual, except in taxa that breed only once. Where generation length varies under threat, the more natural, i.e. pre-disturbance, generation length should be used. There is no data on the age, size at maturity or maximum size of Glyphis sp. A. A 131 cm TL Glyphis sp. C captured in the Adelaide River by Tanaka (1991) was estimated to be 4 years old according to the number of rings on the vertebral centra. Both Glyphis sp. A and C have been reported from the Adelaide River, however, the former appears to be more abundant in this system (R. Pillans, Unpublished data). Although the age of this animal has not been validated, if we assume a size at birth of approximately 50 – 60 cm TL (~55 cm TL) as calculated from animals with open umbilical scars, the growth rate of this animal would have been approximately 19 cm.year-1. When compared to growth rates of bull sharks under 5 years old, this growth rate is similar to bull sharks in Gulf of Mexico which grow at between 15-20 cm.year-1 (Branstetter and Styles, 1987) and similar to growth rates of bull sharks on the east coast of Southern Africa (Winter et al., 2002). Overall growth rates for bull sharks in the U.S and South Africa are between 9 – 11 cm.year-1 (TL). Size at maturity for bull sharks is 210-220 cm TL for males and >225 cm TL for females in the Gulf of Mexico and 240 – 250 cm TL in South Africa (Branstetter and Styles, 1987; Winter et al., 2002, respectively). If we assume similar growth rates to Carcharhinus leucas but smaller size at reproductive age based on data from mature and immature Glyphis sp. C and data from immature Glyphis sp. A, a reasonable estimate of size at maturity would be between 170 – 200 cm TL and maximum size between 230 – 260 cm TL. Generation time would therefore be around 200 – 230 cm TL or 20 – 23 years. Survey effort 21. Has the species been reasonably well surveyed? Provide an overview of surveys to date and the likelihood of its current known distribution and/or population size being its actual distribution and/or population size Although there have been surveys targeting this species, some of which have proved successful, it is likely that Glyphis sp. A does exist in other river systems that have not been surveyed, eluded capture or have been misidentified as bull sharks (Carcharhinus leucas). Future survey efforts should be concentrate on areas such as the Bizant and Normanby River where Glyphis sp. A have been previously recorded and also at sites where there are anecdotal reports of Glyphis; such as the Daly and Mary River. There are also unconfirmed reports of this species in the King and Ord River in Western Australia that need to be investigated as this would be a significant range extension. Prior to 2002, there had been only been two reported surveys of rivers in northern Australia with the specific aim of surveying freshwater sharks and rays. The first was conducted in the eastern Gulf of Carpentaria (Gilbert and Mitchell Rivers) and Northern Territory (Adelaide and Daly Rivers) in 1989 (Taniuchi et al.1991a). Glyphis sp. A was recorded in the Adelaide River by Tanuichi et al., 1991a). The following year a similar survey was made of the Ord and Pentecost Rivers of the northern Kimberley (Ishihara et al. 1991). There have been three recent surveys targeting this species. The first was a NHT funded survey for freshwater elasmobranches in Northern Australia, 147 sites in 39 rivers and creeks in WA, NT and QLD were sampled from June to December 2002 (Thorburn et al., 2003). No specimens of Glyphis sp. A were recorded in this survey despite sites such as the Adelaide River being sampled (where Glyphis sp. A had previously and subsequently been recorded). In a recent DEH funded survye (this report) 27 Glyphis sp. A were captured in the Adelaide River. A recent survey of the Ducie and Wenlock Rivers captured 9 animals (Peverell, 2005). All additional records have come from fish fauna surveys conducted by DPIF (Northern Fisheries Centre), the Museum and Art Gallery of the Northern Territory

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(MAGNT) and Tim Berra (Ohio State University). Threats 31. Identify past, current and future threats, to the species indicating whether they are actual or potential. For each threat, describe:

a. how and where it impacts on this species b. what its effect has been so far (indicate whether it is known or suspected; present supporting

information/research; does it only affect certain populations) c. what is its expected effect in the future (is there supporting research/information; is the threat only suspected;

does it only affect certain populations) The main threat to Glyphis sp. A is commercial gill net fishing (primarily taken as bycatch in coastal barramundi fishery), recreation fishing and habitat modification. Compagno and Cook (1995) note the potential impact of uranium mining in Kakadu National Park where all major river systems contain population of Glyphis sp. A. In the Northern Territory, recent legislation (February 2005), ensured that commercial barramundi fisheries targeting barramundi are excluded from all rivers in which Glyphis sp. A has been recorded. These Rivers are: Adelaide River, South Alligator River, East Alligator River, West Alligator River and Murganella Creek, and fishing is only allowed seaward of an imaginary line drawn across the mouth of the river (Northern Territory of Australia Barramundi Fishery Management Plan, February 2005; Annette Souter, NTDBIRD, personal communication, 2005). Commercial barramundi fishers using 7 inch mesh net are still allowed to fish in all or part of the rivers such as Cooper Creek, Limmen Bight River, Wearyan River, Robinson River and the Victoria River (see Schedule 6, Northern Territory of Australia Barramundi Fishery Management Plan, February 2005, pp 49 -50). Although Glyphis sp. C have not been recorded in these systems, surveys should concentrate on these rivers as any populations within these systems are likely to be impacted by gill net fisheries. As a result of these closures, commercial gill net fishing is unlikely to affect Glyphis sp. C within rivers and estuaries in Northern Territory. However, the influence of this fishery on inshore coastal animals is not known and further research is needed to determine whether this species is captured by commercial barramundi fishers outside of rivers and estuaries. Although bait net fishing is allowed in the Adelaide River and Murganella Creek and all other waters of tidal influence to 3 nautical mile offshore, excluding waters within Kakadu National Park, the small mesh size (2.5 inches) is unlikely to capture even small Glyphis sp. C. Recreation fishing using live and dead bait has the potential to capture Glyphis sp. A. Over a 10 day period on the Adelaide River, we observed 8 animals between 50 – 70 cm TL being captured near the boat ramp under the Arnhem Highway. All of these animals were either killed and eaten or left on the river bank. Given these observations over a short period of time outside of holidays, recreation fishing poses a definite threat to Glyphis sp. A in the Adelaide River. Although recreational fishing is permitted in Kakadu National Park, fishing is restricted to lures only which drastically reduces the chances of capturing Glyphis sp. A. Within Queensland, commercial gill net fisheries targeting barramundi operate in all rivers in which Glyphis sp. A have been reported from or recorded. These Rivers are: Ducie and Wenlock River and Port Musgrave, Bizant River and Normanby River. There are commercial and recreational fishing restrictions in the Bizant River (ie no fishing for 2 km below the road crossing known as the German Bar, -14.670 S 144.131 E), however this closure above the area where Glyphis sp. A was captured in 1982. Sharks, including Glyphis sp. A that are captured in these areas as a bycatch of the barramundi fishery are retained (Stirling Peverell, personal communication, 2005). Commercial fisheries have been operating in these systems prior to the initial discovery of Glyphis sp. A in 1982. There is no long term data to indicate what the past and future effects of this fishery are. As noted previously, additional research into the status of Glyphis sp. A populations in Queensland is urgently required. Recreational fishing and bow hunting also occurs in these systems and could potentially pose a threat to this species. There are reports of Glyphis sp. A being taken by bow and arrow in the Ducie River. There is a definite need to raise the profile of this species amongst recreation fishers to encourage the release of captured animals and also to improve

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identification of specimens. Elasmobranchs living in fresh or estuarine water are bound by the same biological characteristics as marine elasmobranchs: low fecundity, late sexual maturation, long life, and potential for intermittent. Compagno and Cook (1995) not that in addition to these limiting life history characters, elasmobranchs in freshwater are bound by physical constraints (such rivers, streams, estuaries and isolated water bodies) that do not usually influence marine species. The physical constraints limit their ability to evade human-induced problems such as pollutants, habitat modification and destruction, or most importantly, directed and incidental capture in fisheries. Animals like Glyphis, that live within riverine and estuarine habitats are severely restricted by the size of available habitat and are exposed to greater fluctuations in the physical environment such as seasonal and daily variation in salinity, oxygen, turbidity, rate of water movement, presence of water, lack of water, floods and water temperature. Unlike bull sharks that are frequently observed up stream of weirs and barrages, Glyphis sp. A have not been recorded above structural barriers. It is likely that any structural barrier would severely reduce amount of habitat available to this species. 32. If not included above, identify catastrophic threats, i.e. threats with a low predictability that are likely to severely affect the species - Identify the threat, explain its likely impact and indicate the likelihood of it occurring (e.g. a drought/cyclone in the area every 100 years) Not relevant to this species 33. Identify and explain any additional biological characteristics particular to the species that are threatening to its survival (e.g. low genetic diversity)? Identify and explain any models addressing survival of the specie. No genetic studies have been carried out for Glyphis sp. A, however, individuals of Glyphis sp. C captured in Doctors Creek, WA have an abnormally high incidence (ca. 50%) of spinal deformity that could possibly be to due to low genetic diversity (Thorburn and Morgan, 2004). Threat abatement and recovery 34. Identify key management documentation available for the species, e.g. recovery plans, conservation plans, threat abatement plans. Glyphis sp. A was listed as “critically endangered” under the Australian Commonwealth EPBC1999 due the narrow geographic distribution and the estimated population size and decline in numbers or distribution. Unfortunately this Commonwealth listing offers little or no protection to Glyphis sp. A as this species is found almost exclusively within 3 nautical miles of the Australian coastline, where the commonwealth protection begins. The Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes (Pogonoski et al., 2002) identified Glyphis sp. A as “critically endangered”. This report recommended that surveys of northern Australian catchments are urgently required and that a National Recovery Team should be set up to coordinate research into this species. 35. Give an overview of how threats are being abated/could be abated and other recovery actions underway/proposed. Identify who is undertaking these activities and how successful the activities have been to date 36. Which populations are in reserve systems? Which of these are actively managed for this species? Give details Glyphis sp. A living in the South, East and West Alligator Rivers are within Kakadu National Park, managed by Parks Australia North. Although animals within these river systems are protected from legal commercial fisheries, the park is not managed for this species. Habitat is protected from human modification although uranium mining occurs in the Park, the impact of which is not known. The Bizant and Normanby River are within Lakefield National Park, managed by the Queensland Parks and Wildlife Service (QPWS). Glyphis sp. A in these river systems are offered no protection from fishing but are protected from habitat modification.

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Section 2 – Recovery, Conservation, Protection Additional information on legal status 1. Does the species have legal protection under other legislation or political agreements, e.g. Convention on International Trade in Endangered Fauna and Flora (CITES),Convention on Migratory Species (CMS) Not listed on CITES or CMS Additional information on distribution 2. Give locations of: captive/propagated populations; populations recently re-introduced to the wild; and sites for proposed population re-introductions. Note if these sites have been identified in recovery plans Attempts to hold Glyphis sp. A captured in the Adelaide River have been unsuccessful (Deon Wedd, Northern Territory Wildlife Park, personal communication, 12/2004). Additional information on habitat 3. Describe the specie’ non-biological habitat (e.g. aspect, topography, substrate, climate) and biological habitat (e.g. forest type, associated species, sympatric species). If the species uses different habitats for different activities (e.g. breeding, feeding, roosting, dispersing, basking), then describe each habitat The species has only been recorded in highly turbid, tidal rivers and estuaries in Northern Australia in salinities between 0.8 – 28 PPT. Data from the Adelaide River suggests smaller animals (mean ± 1 SD = 70.9± 26.1, n = 36) are more abundant in the upper reaches (80 – 100 km from the mouth) (Figure 2.3.1) whereases in the lower reaches sharks were significantly larger (mean ± 1 SD = 117.4 ± 37.0, n = 19, p < 0.01, Student’s 2-tailed t-Test). Unfortunately salinity in the lower reaches was not recorded, however the presence of “marine species” such as Eusphyra blochii in the same catches suggests the salinity of the water was nearer to seawater (probably between 20 – 30 PPT).

020406080

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0 - 20 km 80 - 100 km

Distance from river mouth

Tota

l len

gth

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) *

Figure 2.3.1. Average size of Glyphis sp. A captured at or near the mouth of the Adelaide River and animals captured 80 – 100 km upstream. Asterisk indicates significant difference between the sizes of animals at the two areas (p < 0.01). See sections 1. 10 to 1.15 for more detailed information on non-biological habitat. 4. Does the species use refuge habitat, e.g. in times of fire, drought or flood? Describe this habitat Not applicable 5. Is the species part of, or does it rely on, a listed threatened ecological community? Is it associated with any other

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listed threatened species? Glyphis sp. A has been captured with Glyphis sp. C in the Adelaide River and the South and East Alligator River. Glyphis sp. C is listed as endangered under the Commonwealth EPBC Act 1999. Glyphis sp. A has been recorded with the freshwater sawfish Pristis microdon in the Adelaide River, East Alligator Rivers and Ducie and Wenlock Rivers. Pristis microdon is listed as “Vulnerable” under the Commonwealth EPBC Act 1999. In the lower reaches of rivers and estuaries it may also co-occur with the green sawfish, Pristis zijsron which is listed as “Endangered” by the IUCN Red List 2003 and listed as an Endangered Species in New South Whales waters under the Fisheries Management Act 1994. Additional information on population 6. Provide details on ages of sexual maturity, life expectancy and natural mortality Only one specimen of Glyphis sp. C has been aged by Tanaka (1991). This 131.4 cm TL animal was an immature female captured in the Adelaide River (Tanuichi et al., 1991). This animal was estimated to be 4 years old based on rings on vertebral centra which would indicate a growth rate of approximately 19 cm.year-1. As no sexually mature animals have been collected, size and age at sexual maturity as well as maximum size are unknown. For a rough estimate of generation length, see section 1.20. 7. Identify important populations necessary for the species’ long-term survival and recovery? This may include: key breeding populations, those near the edge of the species’ range or those needed to maintain genetic diversity Populations in Queensland represent the eastern most distribution of this species and are not protected from commercial fishing to same extent as those in the Northern Territory. These populations, particularly those in the Bizant River have most likely undergone a significant decline due to fishing pressures over the historic past. It is likely that that there is a slow continuing decline within the species current range due to pressures such as barramundi gillnetting, recreational fishing and habitat degradation. Barramundi gillnetting and recreational fishing are of particular concern for this species within this river. Additional surveys of abundance and distribution are required, particularly in Queensland where the population of species appears to have undergone a decline. Survey methods 8. Describe methods for detecting species including when to conduct surveys (e.g. season, time of day, weather conditions); length, intensity and pattern of search effort; and limitations and expert acceptance; recommended methods; survey-effort guide The majority of recorded Glyphis sp. A have been captured by gill nets set in rivers or estuaries. When using gill nets in tidal rivers and estuaries it is preferable to set nets at right angles to the river bank, however this can only be done for brief periods either side of high and low tide due to strong current. In situations where the current prevent setting nets in this way, net can be set parallel to the river banks and although this method is not as effective, sharks are still caught in this manner. When operating in rivers and estuaries, it is preferable to use nets between 30 – 60 m long as longer nets get caught in the current and are difficult to operate. Depth of water dictates the length of the net drop, generally a drop of 2 – 4 m for water between 1 – 6 m deep. When operating in deep channels, nets with a longer drop are better. The size of the mesh used usually dictates the size of animals captured. Neonates between 50 – 80 cm TL have predominantly been captured 4 inch mesh gill nets. Nets with a mesh size of 6 – 7 inches have been used to capture both small and larger sharks. Generally, the larger the mesh size, the larger the sharks caught (see figure 2.8.1). These differences in net selectivity are important in determining the size distribution of the population and it is imperative that a size range of nets are used when sampling for this species. One possible reason for the lack of large mature sharks in the records may be a result of these animals being to too large to be captured in gill nets with a mesh size of 7 inches or less. Indeed, for Glyphis sp. C, the largest recorded animals (144 – 252 cm TL) were captured by commercial longline and the largest recorded animal captured by a gill net was only 141 cm TL (Thorburn and Morgan, 2004). These data indicate that either large mesh nets (greater than 8 inch mesh) and or longlines should be used to adequately sample entire populations of Glyphis sp. A. Longlines have been used to capture Glyphis sp. A in the Adelaide River (Tanuichi et al., 2001), however most longline gear used by researchers would not have been of adequate strength to capture animals larger than 1.8 – 2.0 m TL. As such, we recommend that large tuna circle hooks

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and heavy wire (>150 kg breaking strain) attached to a mainline of at least 500 kg breaking strain with heavy duty shark clips be used. Longlines should be anchored at each end and set on or near the bottom when targeting this species. Figure 2.8.1. Length frequency distribution of Glyphis sp. A captured by 4, 6 and 7 inch mesh gill nets in the Adelaide River.

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Within the NT, Glyphis sp. A has been captured February, March, May, June, September, October, November and December. The best months to sample appear to be November and December, with the most animals being captured in these months. In Queensland, animals have been captured in March and May, however little directed sampling has occurred outside these months. 9. Give details of the distinctiveness and detectability of the species See section 1.5 for more details. The most distinctive characteristic of Glyphis is their large second dorsal fin. Any sharks captured in rivers and estuaries which have a high second dorsal fin (one half to three fifths the height of the first dorsal fin) should be photographed and reported to the nearest museum. Reproduction

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10. For plants: When does the species flower and set fruit? What conditions are needed for this? What is the pollinating mechanism? If the species is capable of vegetative reproduction, a description of how this occurs, the conditions needed and when. Does the species require a disturbance regime (e.g. fire, cleared ground) in order to reproduce? For animals: provide overview of breeding system and of breeding success, including: when does it breed; what conditions are needed for breeding; are there any breeding behaviours that may make it vulnerable to a threatening process? There is no data on the reproductive biology of Glyphis sp. A. Four sexually mature Glyphis sp. C have been recorded and represent the only data available for this genus. Glyphis sp. C apparently mature at a smaller size than Glyphis sp. A. Two mature male Glyphis sp. C were 141 and 142 cm TL, whereas four Glyphis sp. A between 147 and 157 cm TL were not sexually mature based on non calcified claspers. A 177 cm TL female Glyphis sp. C captured on the 17 October 2003 was sexually mature and had 9 early stage embryo’s and associated yolk sac within the uterus. A 252 cm female Glyphis sp. C captured on the same location long line had recently pupped as determined by the distended uteri. These data suggest that pupping occurs prior to the wet season. The lack of yolky ova in the ovaries of both these sharks suggests that Glyphis only breeds every second year. As in other Carcharhinids, the reproductive mode is placental viviparity with females giving birth to live young. Based on data from one Glyphis sp. C litter size is expected to be around 9. Size at birth is probably between 50 – 60 cm TL. As with other euryhaline elasmobranchs, pupping most likely occurs at river mouths or within estuaries. The juveniles moving upstream after birth to escape predation from larger sharks.

Feeding 11. Summarize the species’ food items or sources and timing/seasonality Glyphis sp. A feed primarily on bony fish. Stomachs have contained remains of barramundi (Lates calcarifer) and unidentified fish. 12. Briefly describe the species’ feeding behaviours, including those that may make the species vulnerable to a threatening process There is no data on the feeding behaviour of Glyphis sp. A, however given the turbidity of the water this species is found in, it is likely that vision is of little use to this species. Instead, sharks are most likely capturing prey using elaborate ampullary electroreceptor system to detect the preys low-frequency bioelectric field (see Hueter et al., 2004).

Movements 13. Describe any relevant daily and seasonal pattern of movement for the species, including relevant arrival/departure dates if migratory See part 2 of this report (Acoustic tracking of Glyphis sp. A in the Adelaide River, Northern Territory, Queensland). 14. Give details of the species’ home ranges/territories There is no data on the species homerange. Data collected during short term tracking of Glyphis sp. A in the Adelaide River was not considered appropriate for home range analysis. Other 15. Is there other information that relates to the survival of this species that you would like to address?

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No

Section 3 – References, referees Reference list Blaber, SJM., Brewer, DT and Salini, JP (1989). Species composition and biomasses of fishes in different habitats of a tropical northern Australian estuary: Their occurrence in the adjoining sea and estuarine dependence. Estuarine, Coastal and Shelf Science 29: 509-531. Branstetter, S and Stiles, R (1987). Age and growth estimates of the bull shark, Carcharhinus leucas, from the northern Gulf of Mexico. Environmental Biology of Fishes 20(3):169-181. Compagno, LJV and Cook SF. (1995). The exploitation and conservation of freshwater elasmobranchs: status of taxa and prospects for the future. p 62-90. In: The biology of freshwater elasmobranchs. Asymposium to honor Thomas B. Thorson. Eds: M Oetinger and GD Zorzi. Journal of Aquariculture & Aquatic Sciences, Volume 7.

Compagno, LJV & Niem, VH (1998). Carcharhinidae. In Carpenter, K.E. & Niem, V.H. (eds) ‘FAO Species Identification Guide for Fishery Purposes. The Living Marine Resources of the Western Central Pacific. Volume 2. Cephalopods, crustaceans, holothurians and sharks’. Food and Agriculture Organization of the United Nations, Rome, pp. 1312-1360.

Hazon, N, Wells, A, Pillans, RD, Good, JP, Anderson, WG, Franklin, CE (2003). Urea based osmoregulation and endocrine control in elasmobranch fish with special reference to euryhalinity. Comp. Biochem. Physiol. 136B, 685-700. Heuter, RE, Mann, DA, Maruska, KP, Sisneros, JA and Demski, LS (2004). Sensory biology of elasmobranchs, in Biology of sharks and their relatives. JC Carrier, JA Musick and MR Heithaus, eds. CRC Press, New York, 326 – 368. Last, PR. and Stevens, JD. (1994). Sharks and rays of Australia. C.S.I.R.O. Australia, 513 pp + 84 colour plates. Peverell, SC (2005). Investigating the biology and ecology of northern river shark Glyphis sp. A (Carcharhinidae) recorded in a Cape York River system, 28 pp. Pillans, R.D., Franklin, C.E., 2004. Plasma osmolyte concentrations and rectal gland mass of bull sharks, Carcharhinus leucas, captured along a salinity gradient. Comp. Biochem. Physiol. 138A, 363-371. Pillans, RD, Good, JP, Anderson, WG, Hazon, N, Franklin, CE (2005). Freshwater to seawater acclimation of juvenile bull sharks (Carcharhinus leucas): plasma osmolytes and Na+/K+-ATPase activity in gill, rectal gland, kidney and intestine. J. Comp. Physiol. B, 175, 37-44. Pogonoski, JJ, Pollard, DA and Paxton, JR (2002). Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. Natural Heritage Trust, Environment Australia, 375 pp. Tanaka, S (1991). Age estimation of freshwater sawfish and sharks in northern Australia and Papua New Guinea. The University Museum, University of Tokyo, Nature and Culture No.3: 71-82. Tanuichi, T and Shimizu, M (1991). Elasmobranchs collected from seven river systems in Northern Australia and Papua New Guinea. The University Museum, University of Tokyo, Nature and Culture No. 3: 3-10. Thorburn, DC and Morgan, DL (2004). The northern river shark Glyphis sp. C (Carcharhinidae) discovered in Western Australia. Zootaxa 685: 1 – 8. Thorburn, DC, Peverell, S, Stevens, JD, Last, PR and Rowland, AJ (2003). Status of freshwater and estuarine elasmobranchs in northern Australia. Final Report to Natural Heritage Trust. 75 pp.

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Winter, SP, Dudley, SFJ, Kistasamy, N, Everett, B (2002). Age and growth estimates for the Zambezi shark, Carcharhinus leucas, from the east coast of South Africa. Marine and Freshwater Research 53: 557 – 566.

Dated: Has this document been refereed? If so, indicate who:

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Attachment A – Area of occupancy and extent of occurrence Also see IUCN Guidelines at http://www.iucn.org/themes/ssc/redlists/RedListGuidelines.pdf Extent of occurrence Extent of occurrence is defined as the area contained within the shortest continuous imaginary boundary which can be drawn to encompass all the known, inferred or projected sites of present occurrence of a taxon, excluding cases of vagrancy (see Figure 2). This measure may exclude discontinuities or disjunctions within the overall distributions of taxa (e.g. large areas of obviously unsuitable habitat) (but see 'area of occupancy', point 10 below). Extent of occurrence can often be measured by a minimum convex polygon (the smallest polygon in which no internal angle exceeds 180 degrees and which contains all the sites of occurrence). Area of occupancy Area of occupancy is defined as the area within its 'extent of occurrence' (see point 9 above) which is occupied by a taxon, excluding cases of vagrancy. The measure reflects the fact that a taxon will not usually occur throughout the area of its extent of occurrence, which may contain unsuitable or unoccupied habitats. In some cases (e.g. irreplaceable colonial nesting sites, crucial feeding sites for migratory taxa) the area of occupancy is the smallest area essential at any stage to the survival of existing populations of a taxon. The size of the area of occupancy will be a function of the scale at which it is measured, and should be at a scale appropriate to relevant biological aspects of the taxon, the nature of threats and the available data (see point 7 in the Preamble). To avoid inconsistencies and bias in assessments caused by estimating area of occupancy at different scales, it may be necessary to standardize estimates by applying a scale-correction factor. It is difficult to give strict guidance on how standardization should be done because different types of taxa have different scale-area relationships.

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Figure 2. Two examples of the distinction between extent of occurrence and area of occupancy. (A) is the spatial distribution of known, inferred or projected sites of present occurrence. (B) shows one possible boundary to the extent of occurrence, which is the measured area within this boundary. (C) shows one measure of area of occupancy which can be achieved by the sum of the occupied grid squares.

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Appendix 1.6.1. Summary of all records of Glyphis sp. A collected in Australia to date.

Date Species State/Territory Location Total length (cm) Salinity (ppt) March-1982 Glyphis sp. A QLD Bizant River March-1982 Glyphis sp. A QLD Bizant River

01-Jun-99 Glyphis sp. A NT West Alligator River 115 16.201-Jun-99 Glyphis sp. A NT West Alligator River 116 6.104-Jun-99 Glyphis sp. A NT South Alligator River 79 25.809-Jun-99 Glyphis sp. A NT East Alligator River 147 25.810-Jun-99 Glyphis sp. A NT East Alligator River 78 7.6

15-May-00 Glyphis sp. A NT Murganella creek 122 21-Feb-01 Glyphis sp. A NT East Alligator River 68 18-May-01 Glyphis sp. A NT Adelaide River 59 18-May-01 Glyphis sp. A NT Adelaide River 73 18-May-01 Glyphis sp. A NT Adelaide River 1018-May-01 Glyphis sp. A NT Adelaide River 411-Jun-01 Glyphis sp. A NT West Alligator River 102 13-Jun-01 Glyphis sp. A NT East Alligator River 108 11-Sep-01 Glyphis sp. A NT Adelaide River 68 11-Oct-01 Glyphis sp. A NT Marrakai Creek 68 04-Nov-01 Glyphis sp. A NT Marrakai Creek 61 304-Nov-01 Glyphis sp. A NT Marrakai Creek 307-Oct-03 Glyphis sp. A NT Adelaide River 717-Oct-03 Glyphis sp. A NT Adelaide River 21-Oct-03 Glyphis sp. A NT Adelaide River 31-Oct-03 Glyphis sp. A NT Marrakai Creek 31-Oct-03 Glyphis sp. A NT Marrakai Creek 31-Oct-03 Glyphis sp. A NT Marrakai Creek 31-Oct-03 Glyphis sp. A NT Marrakai Creek 31-Oct-03 Glyphis sp. A NT Marrakai Creek 02-Nov-03 Glyphis sp. A NT Marrakai Creek 02-Nov-03 Glyphis sp. A NT Marrakai Creek 02-Nov-03 Glyphis sp. A NT Marrakai Creek

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Date Species State/Territory Location Total length (cm) Salinity (ppt) 02-Nov-03 Glyphis sp. A NT Marrakai Creek 02-Nov-03 Glyphis sp. A NT Marrakai Creek 03-Nov-03 Glyphis sp. A NT Marrakai Creek 05-Nov-03 Glyphis sp. A NT Adelaide River 05-Nov-03 Glyphis sp. A NT Adelaide River 06-Nov-03 Glyphis sp. A NT Marrakai Creek 07-Nov-03 Glyphis sp. A NT Marrakai Creek 58 807-Nov-03 Glyphis sp. A NT Marrakai Creek 57 807-Nov-03 Glyphis sp. A NT Marrakai Creek 82 807-Nov-03 Glyphis sp. A NT Marrakai Creek 58 807-Nov-03 Glyphis sp. A NT Marrakai Creek 53 817-Nov-03 Glyphis sp. A NT Marrakai Creek 17-Nov-03 Glyphis sp. A NT Marrakai Creek 19-Nov-03 Glyphis sp. A NT Marrakai Creek 20-Nov-03 Glyphis sp. A NT Marrakai Creek 130 20-Nov-03 Glyphis sp. A NT Marrakai Creek 20-Nov-03 Glyphis sp. A NT Marrakai Creek 20-Nov-03 Glyphis sp. A NT Marrakai Creek 20-Nov-03 Glyphis sp. A NT Marrakai Creek 20-Nov-03 Glyphis sp. A NT Marrakai Creek 25-Feb-04 Glyphis sp. A NT Adelaide River mouth 94 26-Feb-04 Glyphis sp. A NT Adelaide River mouth 89 26-Feb-04 Glyphis sp. A NT Adelaide River mouth 75 27-Feb-04 Glyphis sp. A NT Adelaide River mouth 157 27-Feb-04 Glyphis sp. A NT Adelaide River mouth 173 03-Mar-04 Glyphis sp. A NT Adelaide River mouth 114 03-Mar-04 Glyphis sp. A NT Adelaide River mouth 80 03-Mar-04 Glyphis sp. A NT Adelaide River mouth 85 03-Mar-04 Glyphis sp. A NT Adelaide River mouth 88 03-Mar-04 Glyphis sp. A NT Adelaide River mouth 91 03-Mar-04 Glyphis sp. A NT Adelaide River mouth 156

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Date Species State/Territory Location Total length (cm) Salinity (ppt) 04-Mar-04 Glyphis sp. A NT Adelaide River mouth 137 04-Mar-04 Glyphis sp. A NT Adelaide River mouth 133 04-Mar-04 Glyphis sp. A NT Adelaide River mouth 147 04-Mar-04 Glyphis sp. A NT Adelaide River mouth 153 04-Mar-04 Glyphis sp. A NT Adelaide River mouth 152 04-Mar-04 Glyphis sp. A NT Adelaide River mouth 175 06-May-04 Glyphis sp. A QLD Wenlock River 121 1.706-May-04 Glyphis sp. A QLD Wenlock River 106 1.709-Dec-04 Glyphis sp. A NT Marrakai Creek 61 509-Dec-04 Glyphis sp. A NT Marrakai Creek 58 509-Dec-04 Glyphis sp. A NT Marrakai Creek 66 5.411-Dec-04 Glyphis sp. A NT Marrakai Creek 50 5.211-Dec-04 Glyphis sp. A NT Marrakai Creek 62 5.211-Dec-04 Glyphis sp. A NT Marrakai Creek 65 5.211-Dec-04 Glyphis sp. A NT Marrakai Creek 62 5.211-Dec-04 Glyphis sp. A NT Marrakai Creek 62 5.211-Dec-04 Glyphis sp. A NT Adelaide River 60 5.511-Dec-04 Glyphis sp. A NT Adelaide River 64 5.511-Dec-04 Glyphis sp. A NT Marrakai Creek 62 5.112-Dec-04 Glyphis sp. A NT Marrakai Creek 60 5.212-Dec-04 Glyphis sp. A NT Marrakai Creek 63 5.212-Dec-04 Glyphis sp. A NT Marrakai Creek 62 5.212-Dec-04 Glyphis sp. A NT Marrakai Creek 63 5.212-Dec-04 Glyphis sp. A NT Marrakai Creek 90 4.714-Dec-04 Glyphis sp. A NT Marrakai Creek 64 4.714-Dec-04 Glyphis sp. A NT Marrakai Creek 62 4.714-Dec-04 Glyphis sp. A NT Marrakai Creek 62 4.514-Dec-04 Glyphis sp. A NT Marrakai Creek 165 3.716-Dec-04 Glyphis sp. A NT Marrakai Creek 86 4.516-Dec-04 Glyphis sp. A NT Marrakai Creek 61 4.517-Dec-04 Glyphis sp. A NT Marrakai Creek 62 4.5

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Date Species State/Territory Location Total length (cm) Salinity (ppt) 17-Dec-04 Glyphis sp. A NT Marrakai Creek 65 4.517-Dec-04 Glyphis sp. A NT Marrakai Creek 61 4.517-Dec-04 Glyphis sp. A NT Marrakai Creek 158 4.819-Dec-04 Glyphis sp. A NT Adelaide River 151 18.218-Mar-05 Glyphis sp. A QLD Port Musgrave 19-Mar-05 Glyphis sp. A QLD Port Musgrave 20-Mar-05 Glyphis sp. A QLD Port Musgrave

May-05 Glyphis sp. A QLD Port Musgrave May-05 Glyphis sp. A QLD Port Musgrave May-05 Glyphis sp. A QLD Port Musgrave May-05 Glyphis sp. A QLD Port Musgrave May-05 Glyphis sp. A QLD Port Musgrave May-05 Glyphis sp. A QLD Port Musgrave May-05 Glyphis sp. A QLD Port Musgrave

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Section 1 – Conservation Assessment Information required for assessing species nominated as threatened under the EPBC Act. Answer all parts, indicating when there is no information available. Taxonomy

1. What are the currently accepted scientific and common name/s for the species? Note any other scientific names that have been recently used

Scientific name Common name Glyphis sp. C Northern River shark, northern spear tooth

Shark

2. Is this species conventionally accepted? If not, explain why. Is there any controversy on the taxonomy? Yes this species is conventionally accepted (Last and Stevens, 1994; Compagno and Niem, 1998, Thorburn and Morgan 2004). There is some confusion over the taxonomy and distribution of this species with some reports of it being found in Papua New Guinea (Thorburn and Morgan, 2004; 2005). All available data indicates that it is restricted to Australia.

3. Describe any cross-breeding with other species in the wild, indicating how frequently and where this occurs There is no evidence of cross breeding between the two members of this genus found in Australia (Glyphis sp. C and Glyphis sp. A). Legal status 4. What is the species’ current conservation status under Australian and State/Territory Government legislation? Glyphis sp. C is listed as endangered under the Environment Protection Biodiversity and Conservation Act

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1999(EPBC Act 1999). This species has been listed since 2001. Glyphis sp. C is not listed under State Government legislation in the three states in which it occurs (ie Western Australia, Northern Territory). Glyphis sp. C is listed as critically endangered by the IUCN Red List 2003. Description 5. Give a brief description of the species’: appearance, including size and/or weight, and sex and age variation if appropriate; social structure and dispersion (e.g. solitary/clumped/flocks)

Glyphis sp. C belongs to the family Carcharhinidae. They are medium-sized whaler sharks, greyish on the dorsal surface and white below, without a distinctive color pattern and no interdorsal ridge. The second dorsal fin is between half to three fifths the height of first dorsal fin and its origin is slightly anterior to the anal fin origin. They have short and broadly rounded snouts, and erect, broadly triangular, serrated upper teeth, the lower teeth are long and slender with the cusps smooth basally but with serrated, spear-like expanded tips (Last & Stevens, 1994; Compagno and Niem, 1998). Glyphis sp. C has fewer vertebrae (142 - 151) than Glyphis sp. A (198 - 217). Glyphis sp. C lacks the black or dusky tips on the venrtal surface of the pectoral fins which are present in Glyphis sp. A. The eye is small, being between 0.77-1.03 % of total length (TL).

Maximum recorded size is 251 cm TL for females and 142 cm TL for males. Both of these animals and others of similar size were sexually mature. The smallest sexually mature female and male were 177 cm TL and 142 cm TL, respectively. Based on the size of largest mature female, maximum size is likely to be around 251 – 300 cm TL.

Juveniles of this species have been recorded in riverine and freshwater environments whereas adults and subadults have been recorded in both marine and riverine environments. This suggests that this species utilises river and estuaries as a nursery area with larger (older) animals moving out to marine environments. It is likely that Glyphis sp. C has similar life history characteristic to the bull shark (Carcharhinus leucas) (Thorson et al., 1973; Last and Stevens, 1994).

6. Identify major studies on the species This species is currently only known from 29 specimens in Australia (see Appendix 1.6.1). It was first recorded in Australia from the Adelaide River by Tanuichi et al. (1991). Tanaka (1991) subsequently estimated this 131 cm TL female to be 4 years old. Another specimen was captured by a recreational fisher about 60 km up the South Alligator River in 1996(John Stevens, CSIRO Marine Research, personal communication.) (see Last, 2002). An additional 2 specimens were captured by fish surveys being conducted in the East Alligator River by the Museum and Art Gallery of the Northern Terrirtory (MAGNT) (Larson, 2000). Glyphis sp. C was first recorded in WA in June 2002 when Morgan et al (2004) captured a specimen in Doctors Creek. A subsequent survey of this region (King Sound) captured an additional 6 specimens (Thorburn and Morgan, 2004). Thorburn and Morgan (2004) described the habitat the animals were captured in as well as their morphology and biology. Much of this work is also summarised by Thorburn and Morgan (2005). Additional data on this species has come from observers in an FRDC funded project led by CSIRO “Northern Australian Sharks and Rays, the sustainability of target and bycatch species” Phase 2 (FRDC 2002/064) as well as data provided by recreational fishers.

International context (for species that are distributed both inside and outside Australia’s jurisdiction) 7. Describe the species’ global distribution Glyphis sp. C is believed to be an Australian endemic

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See also section 1. 8. Give an overview of the global population’s size, trends, threats and security of the species outside Australia Glyphis sp. C has not been recorded outside of Australian waters. Members of the Glyphis genus have been recorded from South East Asia (India, Pakistan, Borneo and New Guinea) and are either presumed extinct or very uncommon in these areas. The Ganges river shark, Glyphis gangeticus is known from Ganges and Hooghly Rivers, India and possibly from Karachi in Pakistan. This species in known from only three museum species and despite intensive surveys in the past 10 years only one additional specimen and two sets of jaws have been collected. The Borneo River shark, Glyphis sp. B was previously known from one specimen in a museum in Vienna that was collected from a river in Borneo over 100 years ago. This species was assumed to be extinct until it was “rediscovered” in the Kinabatangan River in northern Borneo in 1996. 9. Explain the relationship between the Australian population and the global population, including:

d. What percentage of the global population occurs in Australia; e. Is the Australian population distinct, geographically separate or does part or all of the population move in/out

of Australia’s jurisdiction (give an overview; details in Movements section); f. Do global threats affect the Australian population?

The population size of Glyphis sp. C is unknown. Given the large increase in illegal fishing within Australian waters, it is likely that the methods employed by these vessels (large mesh gill nets and long lines) would catch adult Glyphis sp. C. National context Distribution 10. Describe the species’ distribution in Australia and, if available, attach a map Glyphis sp. C has been recorded in rivers and estuaries as well as marine environment within Western Australia and The Northern Territory (Figure 1.10.1).

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17° 17°

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Joseph Bonaparte Gulf

King Sound King RiverOrd River

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East Alligator River

Wessel Islands

South Alligator River

Figure 1.10.1. Distribution of Glyphis sp. C within Australia. Distribution is based on all known specimens that have been identified (n =29). In Western Australia, records have come from within King Sound, the Ord and King Rivers, West Arm of Cambridge Gulf and also from Joseph Bonaparte Gulf. King Sound is a macrotidal (tides up to 10 m twice daily) mangrove estuary north of Derby. Salinity and temperature where Glyphis sp. C was captured ranged from 32.0 – 36.6 parts per thousand (PPT) and 22 – 23 ºC, respectively. Turbidity was high with secci depths of only 3-4 cm. No data on salinity or temperature are available for the animals captured in the Ord and King River, Cambridge and Joseph Bonaparte Gulf. However, given that it was the dry season when animals were captured in Joseph Bonaparte Gulf, the salinity was almost certainly that of seawater (approximately 30 – 36 PPT). Within the Northern Territory, Glyphis sp. C have been recorded from the highly turbid lower reaches (salinity between 3 and 10 PPT) of the Adelaide River and the South and East Alligator Rivers (Larson, 2002, Tim Berra, personal communication.). Glyphis sp. C has also been recorded off the Wessel Islands in full strength seawater. 11. What is the extent of occurrence (in km2) for the species (described in Attachment A); explain how it was calculated and datasets used

d. What is the current extent of occurrence? e. What data is there to indicate past declines in extent of occurrence (if available, include data that indicates

the percentage decline over the past 10 years or 3 generations whichever is longer)? f. What data is there to indicate future changes in extent of occurrence (if available, include data that indicates


d. Glyphis sp. C have been recorded from King Sound, WA to the Wessel Islands, NT. Their distribution

between these locations is not continuous and they have only been recorded from a few highly turbid, tidal rivers and estuaries in northern Australia. There are also a few records of this species from the marine

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environment, including specimens captured in Josheph Bonaparte Gulf and off the Wessel Islands. Although the record off the Wessel Islands is only one specimen, commercial long line fishers in this area have reported catching additional specimens. Given the presence of adults around the Wessel Island (at least 80 km from the mainland), it is apparently not restricted to rivers and estuaries and can be found far from inshore estuarine environments. Glyphis species have also been recorded (based on jaws collected from commercial fishers) in a marine environment within Van Diemen Gulf (mouth of Love Creek, approximately 12.29 S, 132. 01 E) however it is unknown what species they were. Given the size of jaws (TL estimated to be greater than 2.4 m) and that they were from a marine environment, it is likely that it was Glyphis sp. C. That Glyphis sp. C has only been found in 5 coastal river systems, with only one offshore record, suggests they have specific habitat requirements and are only restricted to a few river systems. A Natural Heritage Trust (NHT) funded survey of freshwater elasmobranchs surveyed 17 rivers and estuaries between the Fitzroy River and the Glyde River and did not record any Glyphis sp. C (Thorburn et al., 2003). Glyphis sp. C have subsequently been recorded from some of these rivers systems highlighting the rarity of these sharks not only throughout the region but also within the systems that they are found in.

e. There is no data to indicate a decline in the extent of occurrence; in fact recent records are expanding the

species distribution. The remote areas in which this species occurs have resulted in it not being adequately sampled and have also hopefully protected it from overexploitation in these areas. This expansion of range is a result of increased sampling effort, directed surveys and increased awareness of commercial and recreational fishers rather than an increase in abundance.

There is no data to suggest that future changes in the extent of occurrence will occur. However, given the increase in the number of records in the past three years it is anticipated that the distribution of Glyphis sp. C may increase to include additional river systems as well marine environments in Northern Australia. 12. What is the area of occupancy (in km2) for the species (described in Attachment A; explain how calculated and datasets that are used)

d. What is the current area of occupancy? e. What data is there to indicate past declines in area of occupancy (if available, include data that indicates the

percentage decline over the past 10 years or 3 generations whichever is longer)? f. What data is there to indicate future changes in area of occupancy (if available, include data that indicates


d. The area of occupancy of Glyphis sp. C is approximately 10 000 km2. This value will increase significantly

with additional marine records. This value was calculated by summing the area (km2) of each river system/estuary, sound, bay and marine area that Glyphis sp. C has been recorded in. The area of the entire river system from the mouth to the first dry season barrier was assumed to be suitable habitat and was therefore used. Area was calculated using the “draw polygon” feature in ArcView GIS 3.3 and is the sum of area. The area of occupancy is significantly larger than Glyphis sp. A as due to the presence of animals in marine environment.

e. There are insufficient data to suggest a decline in the area of occupancy.

f. There is currently insufficient data to suggest that area of occupancy will be reduced in the future. The area of

occupancy is likely to be increased as a result of additional records of this species from rivers/estuaries and the marine environment within their current range. This species appears to be naturally rare with low population size. As a result of this, changes in the area of occupancy as well changes in abundance will be difficult to detect.

13. Is the species’ distribution severely fragmented? Why? Severely fragmented refers to the situation in which increased extinction risk to the taxon results from most individuals being found in small and relatively isolated subpopulations (in certain circumstances this may be inferred from habitat information). These small subpopulations may go extinct, with a reduced probability of recolonization. More data is required to determine whether the distribution of Glyphis sp. C is fragmented. Available data suggests

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that there are four locations where this species occurs and that there are large distances between the locations (Appendix A). The presence of animals well offshore suggests they do undertake offshore movements away from the rivers and estuaries and are therefore likely to move between river systems, however the extent to which this occurs and the distances moved are unknown. Additional data on the distribution and movement of Glyphis sp. C as well population genetic analyses are needed to determine the degree of fragmentation. The high incidence (ca. 50%) of spinal deformities in sharks captured in King Sound may represent a genetic deformity associated with a small gene pool. 14. How many locations do you consider the species occurs in and why? The term 'location' defines a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the species present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a species is affected by more than one threatening event, location should be defined by considering the most serious plausible threat. Based on available data, there are currently four geographically distinct locations in which the species occurs. These are: 1) King Sound, WA, including Doctors Creek; 2) Joseph Bonaparte Gulf, WA, including Cambridge Gulf and the Ord and King Rivers; 3) Van Dieman Gulf drainages, NT, including the Adelaide River, South and East Alligator Rivers and possible from within Van Diemen Gulf based on jaws from Glyphis species collected by commercial fishers in this area (see section 1.11) and 4) The Wessel Islands, particularly west of Marchinbar Island. The area in King Sound in which Glyphis sp. C have been recorded has been identified as a potential site to be dammed for electricity generation using tidal energy. Commercial long line vessels fishing for sharks in Joseph Bonaparte Gulf have captured up to 7 adult Glyphis sp. C in one week of fishing (CSIRO Marine Research, unpublished data). Long line fisheries targeting sharks in inshore coastal environments are to date, the only fishery in which Glyphis sp. C has been recorded. The animal recorded from the Wessel Islands, and other unconfirmed reports, were also captured by commercial long line. It is uncertain whether a population of Glyphis sp. C exists in this location or whether sharks are moving between areas. The capture of large sexually mature Glyphis sp. C by long lines is concerning and further investigation into these captures are required. These fisheries (WA Northern Shark Joint Authority Fishery (WAFJA) and NT Joint Authority Shark Fishery ( NTFJA)) operate within three nautical miles of the coast are managed by the WA and NT governments. These fisheries can legally capture Glyphis sp. C (despite it being listed as endangered by the Commonwealth EPBC 1999 Act) as long as animals are captured within 3 nautical miles of the coast. Glyphis sp. C have been found in 3 rivers systems that flow into the Van Dieman Gulf, a total area of 290 km2. This region appears to be centre of abundance for this species and is the only place where Glyphis sp. C are known to occur in adjacent river systems. Given the proximity of these rivers (less than 115 km apart), it is not unreasonable to assume that animals would be capable of moving between river systems. The South and East Alligator Rivers are within Arnhem Land and Kakadu National Park and animals within these systems are therefore not exposed to commercial fishing or any form of habitat modification. The boundary for commercial barramundi fishing in the Adelaide River has recently been extended to the mouth of the River, effectively protecting Glyphis sp. C from commercial fishing in this river. As noted, this species has most likely also been captured by commercial Habitat 15. Give a brief description of the species’ habitat/s (Details entered in Section 2)

Data from only 29 individuals indicates that Glyphis sp. C utilise large tropical river systems, macrotidal embayments, as well as inshore marine habitats. Most large specimens have come from marine environments and the smallest recorded animals from rivers, however a 131 cm TL female and a 91 cm TL male have been captured in 3 PPT and 32 PPT, respectively. The small amount of data collected on the physical properties of rivers systems Glyphis sp. A have been captured in indicates a preference for highly turbid, tidally influenced waters with fine muddy substrate. Animals have been captured in temperatures ranging from 22.3 – 31.0 º C.

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This species appears to have a broad salinity tolerance and has been recorded in salinities between 3.0 and 36.6 PPT. Given the range of salinity it has been recorded in, it is a euryhaline elasmobranch capable of living in and moving between freshwater and seawater. The physiological specialisations that enable it to live in both freshwater and seawater are likely to be similar to that of bull sharks (see Hazon et al., 2003; Pillans and Franklin, 2004; Pillans et al., 2005).

Populations 16. What is the species’ total population size in terms of number of mature individuals? Are there other useful measures of population size and what are they? In the absence of figures, terms such as common, abundant, scarce can be of value. There are no available estimates of population size of Glyphis sp. C. 17. Does the species occur in a number of smaller populations? How many? If available, for each population give the locality, numbers and trends in numbers and tenure of land (if available) (include extinct populations). Can these be considered to be subpopulations and why? Subpopulations are defined as geographically or otherwise distinct groups in the population between which there is little demographic or genetic exchange (typically one successful migrant individual or gamete per year or less). This species may occur in different subpopulations, however there is no estimate of their size. See section 1.14 for more information on subpopulations. 18. What is the population trend for the entire species?

c. What data is there to indicate past decline in size (if available, include data on rate of decline over past 10 years or 3 generations whichever is longer)?

d. What data is there to indicate future changes in size (if available, include data which will indicate the percentage of decline over 10 years or 3 generations whichever in longer (up to a maximum of 100 years in the future) where the time period is a continuous period that may include a component of the past)?

There are insufficient data to demonstrate a population decline. Available data suggest that population numbers are low. 19. Does the species undergo extreme natural fluctuations in population numbers, extent of occurrence or area of occupancy? To what extent and why? Extreme fluctuations can be said to occur in a number of taxa when population size or distribution area varies widely, rapidly and frequently, typically with a variation greater than one order of magnitude (i.e. a tenfold increase or decrease). Given the stable life history of elasmobranchs (ie long lived, slow growing, low fecundity, production of a small number of well developed you) they are not generally prone to large natural fluctuations in population numbers. 20. What is the generation length and how it is calculated? Generation length is the average age of parents of the current cohort (i.e. newborn individuals in the population). Generation length therefore reflects the turnover rate of breeding individuals in a population. Generation length is greater than the age at first breeding and less than the age of the oldest breeding individual, except in taxa that breed only once. Where generation length varies under threat, the more natural, i.e. pre-disturbance, generation length should be used. There is no data on the age, size at maturity or maximum size of Glyphis sp. A. A 131 cm TL Glyphis sp. C captured in the Adelaide River by Tanaka (1991) was estimated to be 4 years old according to the number of rings on the vertebral centra. Although the age of this animal has not been validated, if we assume a size at birth of approximately 50 – 60 cm TL (~55 cm TL) based on data from the smallest recorded animals, the growth rate of this animal would have been approximately 19 cm.year-1. When compared to growth rates of bull

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sharks under 5 years old, this growth rate is similar to bull sharks in Gulf of Mexico which grow at between 15-20 cm.year-1 (Branstetter and Styles, 1987) and similar to growth rates of bull sharks on the east coast of Southern Africa (Winter et al., 2002). Overall growth rates for bull sharks in the U.S and South Africa are between 9 – 11 cm.year-1

(TL). Size at maturity for bull sharks is 210-220 cm TL for males and >225 cm TL for females in the Gulf of Mexico and 240 – 250 cm TL in South Africa (Branstetter and Styles, 1987; Winter et al., 2002, respectively). If we assume similar growth rates to Carcharhinus leucas but smaller size at reproductive age based on data from mature and immature Glyphis sp. C, a reasonable estimate of size at maturity would be between 142 cm TL for males and 177 cm TL for females with a maximum size between 250 – 280 cm TL. Generation time would therefore be around 190 – 220 cm TL or 19 – 22 years. Survey effort 21. Has the species been reasonably well surveyed? Provide an overview of surveys to date and the likelihood of its current known distribution and/or population size being its actual distribution and/or population size Although there have been surveys targeting this species, some of which have proved successful, it is likely that Glyphis sp. C does exist in other river systems that have not been surveyed, eluded capture or have been misidentified as bull sharks (Carcharhinus leucas). Future survey efforts should concentrate on areas such as the Ord and King River where Glyphis sp. C have been recorded by recreational fishers and also at sites where there are anecdotal reports of Glyphis such as the Daly and Mary River. Addional Rivers in Western Australia should also be sampled. Prior to 2002, there had been only been two reported surveys of rivers in northern Australia with the specific aim of surveying freshwater sharks and rays. The first was conducted in the eastern Gulf of Carpentaria (Gilbert and Mitchell Rivers) and Northern Territory (Adelaide and Daly Rivers) in 1989 (Taniuchi et al.1991a). Glyphis sp. C was recorded in the Adelaide River by Tanuichi et al., 1991a). The following year a similar survey was made of the Ord and Pentecost Rivers of the northern Kimberley but no Glyphis sp. C were recorded (Ishihara et al. 1991). There have been three recent surveys targeting this species. The first was a NHT funded survey for freshwater elasmobranches in Northern Australia, 147 sites in 39 rivers and creeks in WA, NT and QLD were sampled from June to December 2002 (Thorburn et al., 2003). No specimens of Glyphis sp. C were recorded in this survey despite sites such as the Adelaide River being sampled (where this species had previously and subsequently been recorded). The first record of Glyphis sp. C in Western Australia was a 99 cm TL male was captured in Doctors Creek (Morgan et al., 2004). Subsequent surveys of this region captured an additional six specimens with Doctors Creek and King Sound (Thorburn et al., 2004). Threats 31. Identify past, current and future threats, to the species indicating whether they are actual or potential. For each threat, describe:

d. how and where it impacts on this species e. what its effect has been so far (indicate whether it is known or suspected; present supporting

information/research; does it only affect certain populations) f. what is its expected effect in the future (is there supporting research/information; is the threat only suspected;

does it only affect certain populations) The main threat to Glyphis sp. C is commercial gill net fishing (primarily taken as bycatch in coastal barramundi fishery), recreation fishing and habitat modification. Compagno and Cook (1995) note the potential impact of uranium mining in Kakadu National Park where Glyphis sp. C have been recorded. In the Northern Territory, recent legislation (February 2005), ensured that commercial barramundi fisheries targeting barramundi are excluded from all rivers in which Glyphis sp. C has been recorded. These Rivers are: Adelaide River, South Alligator River, East Alligator River, West Alligator River and Murganella Creek, and fishing is only allowed seaward of an imaginary line drawn across the mouth of the river (Northern Territory of Australia Barramundi Fishery Management Plan, February 2005; Annette Souter, NTDBIRD, personal communication, 2005). Commercial

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barramundi fishers using 7 inch mesh net are still allowed to fish in all or part of the rivers such as Cooper Creek, Limmen Bight River, Wearyan River, Robinson River and the Victoria River (see Schedule 6, Northern Territory of Australia Barramundi Fishery Management Plan, February 2005, pp 49 -50). Although Glyphis sp. C have not been recorded in these systems, surveys should concentrate on these rivers as any populations within these systems are likely to be impacted by gill net fisheries. As a result of these closures, commercial fishing is unlikely to affect Glyphis sp. C within rivers and estuaries in Northern Territory. However, the influence of this fishery on inshore coastal animals is not known and further research is needed to determine whether this species is captured by commercial barramundi fishers outside of rivers and estuaries. Based on the information of the capture of a large unidentified Glyphis species (likely to have been Glyphis sp. C) in a marine environment from Northern Territory Barramundi fishery (Peter Last, CSIRO Marine Research, personal communication.) it is likely that this fishery poses an additional threat to this species. The catch composition of elasmobranchs within this fishery has been poorly documented and more data is required from this fishery in order to assess its effects on this species. Commercial fisheries targeting sharks within 3 nautical miles of the coastline have captured Glyphis sp. C around the Wessel Islands. Effort in this fishery has been reduced and new logbooks will record the capture of this species (David McKee, NTDIRD, personal communication, 05/05). Catches of this species in offshore waters should be monitored closely in order to increase our knowledge of this species and ensure that capture in these fisheries is sustainable. Although bait net fishing is allowed in the Adelaide River and all other waters of tidal influence to 3 nautical miles offshore, excluding waters within Kakadu National Park, the small mesh size (2.5 inches) is unlikely to capture even small Glyphis sp. C. Although no recreation catches of Glyphis sp. C have been recorded in NT, there is the potential for fishers using live or dead bait to capture them in the Adelaide River. The chances of recreational fishers catching Glyphis sp. C in the South and East Alligator Rivers is very slim. This is due to live and dead bait not being allowed in these rivers. Within Western Australia, there is commercial gill netting for barramundi (Lates calcarifer) and king salmon (Eleutheronema tetradactylum) within King Sound and the Cambridge Gulf / Joseph Bonaparte Gulf area. These fisheries are restricted by the number of licences (there are currently 2 active licences in each area). Within the Ord and King Rivers, commercial fishing is not allowed upstream of Adolphus Island (Rory McCauley, WA Fisheries, 05/05 personal communication.). Adolphus Island is downstream of all locations where Glyphis sp. C has been recorded and this closure may inadvertently protect populations of Glyphis sp. C within the Ord River system. Although there are no records of Glyphis sp. C from commercial fishers fishing outside of these closures, it is likely that they are captured and retained. Similarly, although no Glyphis sp. C have been recorded in the WAFJA, it is likely that they are captured in this fishery, given the overlap with NTFJA. Recreation fishing using live and dead bait has the potential to capture Glyphis sp. C. All data from the Ord and King River and Cambridge Gulf was obtained from a recreational fisher who photographed, measured and recorded the location of capture of five juvenile Glyphis sp. C captured while fishing for barramundi and king salmon. While all of these animals were released alive, it is likely that other sharks are retained or discarded dead within this system. An additional threat to the King Sound population is the proposed damming of the Fitzroy River for tidally generated electricity (Thorburn and Morgan, 2005). Any alteration of tidal flow and therefore habitat are likely to be detrimental to this species which appears to have a very narrow habitat preference. Elasmobranchs living in fresh or estuarine water are bound by the same biological characteristics as marine elasmobranchs: low fecundity, late sexual maturation, long life, and potential for intermittent. Compagno and Cook (1995) not that in addition to these limiting life history characters, elasmobranchs in freshwater are bound by physical constraints (such rivers, streams, estuaries and isolated water bodies) that do not usually influence marine species. The physical constraints limit their ability to evade human-induced problems such as pollutants, habitat modification and destruction, or most importantly, directed and incidental capture in fisheries. Animals like Glyphis, that live within riverine and estuarine habitats are severely restricted by the size of available habitat and are exposed to greater fluctuations in the physical environment such as seasonal and daily variation in salinity, oxygen, turbidity, rate of water movement, presence of water, lack of water, floods and water temperature. Unlike bull sharks that are

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frequently observed up stream of weirs and barrages, Glyphis sp. C have not been recorded above structural barriers. It is likely that any structural barrier would severely reduce amount of habitat available to this species. 32. If not included above, identify catastrophic threats, i.e. threats with a low predictability that are likely to severely affect the species - Identify the threat, explain its likely impact and indicate the likelihood of it occurring (e.g. a drought/cyclone in the area every 100 years) Not relevant to this species 33. Identify and explain any additional biological characteristics particular to the species that are threatening to its survival (e.g. low genetic diversity)? Identify and explain any models addressing survival of the specie. No genetic studies have been carried out for Glyphis sp. C, however, individuals of Glyphis sp. C captured in Doctors Creek, WA have an abnormally high incidence (ca. 50%) of spinal deformity that could possibly be to due to low genetic diversity (Thorburn and Morgan, 2004). Threat abatement and recovery 34. Identify key management documentation available for the species, e.g. recovery plans, conservation plans, threat abatement plans. Glyphis sp. A was listed as “endangered” under the Australian Commonwealth EPBC1999 due the narrow geographic distribution and the estimated population size and decline in numbers or distribution. Unfortunately this Commonwealth listing offers little or no protection to Glyphis sp. C as this species is found almost exclusively within 3 nautical miles of the Australian coastline, where the commonwealth protection begins. The Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes (Pogonoski et al., 2002) identified Glyphis sp. A as “endangered”. This report recommended that surveys of northern Australian catchments are urgently required and that a National Recovery Team should be set up to coordinate research into this species. 35. Give an overview of how threats are being abated/could be abated and other recovery actions underway/proposed. Identify who is undertaking these activities and how successful the activities have been to date See section 1.30 36. Which populations are in reserve systems? Which of these are actively managed for this species? Give details Glyphis sp. C living in the South and East Alligator Rivers are within Kakadu National Park, managed by Parks Australia North. Although animals within these river systems are protected from legal commercial fisheries, the park is not managed for this species. Habitat is protected from human modification although uranium mining occurs in the Park, the impact of which is not known.

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Section 2 – Recovery, Conservation, Protection Additional information on legal status 1. Does the species have legal protection under other legislation or political agreements, e.g. Convention on International Trade in Endangered Fauna and Flora (CITES),Convention on Migratory Species (CMS) Not listed on CITES or CMS Additional information on distribution 2. Give locations of: captive/propagated populations; populations recently re-introduced to the wild; and sites for proposed population re-introductions. Note if these sites have been identified in recovery plans Not applicable Additional information on habitat 3. Describe the specie’ non-biological habitat (e.g. aspect, topography, substrate, climate) and biological habitat (e.g. forest type, associated species, sympatric species). If the species uses different habitats for different activities (e.g. breeding, feeding, roosting, dispersing, basking), then describe each habitat The species has been recorded in highly turbid, tidal rivers and estuaries and sounds in Northern Australia in salinities between 3.0 – 36.6 PPT. It has also been recorded in inshore coastal habitat in Joseph Bonaparte Gulf as well as off the Wessel Islands in 20-25 m of water. It appears to have a preference for highly turbid water with animals being recorded in water with secci depths of 3-4 cm. See sections 1. 10 to 1.15 for more detailed information on non-biological habitat. 4. Does the species use refuge habitat, e.g. in times of fire, drought or flood? Describe this habitat Not applicable 5. Is the species part of, or does it rely on, a listed threatened ecological community? Is it associated with any other listed threatened species? Glyphis sp. C has been captured with Glyphis sp. A in the Adelaide River and the South and East Alligator River. Glyphis sp. C is listed as endangered under the Commonwealth EPBC Act 1999. Glyphis sp. C has been recorded with the freshwater sawfish Pristis microdon in the Adelaide River and East Alligator Rivers. Pristis microdon is listed as “Vulnerable” under the Commonwealth EPBC Act 1999. In the lower reaches of rivers and estuaries and in marine environment it co-occurs with the green sawfish, Pristis zijsron which is listed as “Endangered” by the IUCN Red List 2003 and listed as an Endangered Species in New South Whales waters under the Fisheries Management Act 1994. Additional information on population 6. Provide details on ages of sexual maturity, life expectancy and natural mortality Only one specimen of Glyphis sp. C has been aged by Tanaka (1991). This 131.4 cm TL animal was an immature female captured in the Adelaide River (Tanuichi et al., 1991). This animal was estimated to be 4 years old based on rings on vertebral centra which would indicate a growth rate of approximately 19 cm.year-1. Based on these growth rates and similarity between early growth rates of the bull shark, an overall estimate of growth rate (9 - 11 cm.year-1) was used to estimate age at maturity (see section 1.20). Using this estimate of growth and limited data from only 4 animals, age at maturity for males and females is approximately 14 and 17 years, respectively. Maximum age is expected to be greater than 25 years given the maximum recorded size of 252 cm TL. 7. Identify important populations necessary for the species’ long-term survival and recovery? This may include: key breeding populations, those near the edge of the species’ range or those needed to maintain genetic diversity See section 1.13 and 1.14

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Survey methods 8. Describe methods for detecting species including when to conduct surveys (e.g. season, time of day, weather conditions); length, intensity and pattern of search effort; and limitations and expert acceptance; recommended methods; survey-effort guide The majority of recorded Glyphis sp. C have been captured by gill nets set in rivers/estuaries. When using gill nets in tidal rivers and estuaries it is preferable to set nets at right angles to the river bank, however this can only be done for brief periods either side of high and low tide due to strong current. In situations where the current prevent setting nets in this way, net can be set parallel to the river banks and although this method is not as effective, sharks are still caught in this manner. When operating in rivers and estuaries, it is preferable to use nets between 30 – 60 m long as longer nets get caught in the current and are difficult to operate. Nets should be monitored constantly as animals will die if left in nets for long periods. Depth of water dictates the length of the net drop, generally a drop of 2 – 4 m for water between 1 – 6 m deep. When operating in deep channels, nets with a longer drop are better. The size of the mesh used usually dictates the size of animals captured. Glyphis sp. C between 58 and 142 cm TL have been captured with 4, 6 and 8 inch mesh gillnets. Larger animals between 142 and 252 cm TL have been captured by commercial long lines. A variety of net sizes between 4 and 8 inches as well as heavy long lines should be utilised when sampling rivers and estuaries. Commercial long lines consist of a 1 metre length of 400 kg wire attached to 2 m of 9 mm rope which is attached to a 9 - 12 mm mainline. Similar gear should be used when sampling for this species as larger specimens are capable of breaking lighter gear. In King Sound, Glyphis sp. C have only been captured in June (Morgan et al., 2004, Thorburn et al., 2004). This species has not been recorded in the nearby Fitzroy River despite surveys in this area (Thorburn et al., 2004). Within Joseph Bonaparte Gulf, animals have been captured offshore in October and within Cambridge Gulf and the Ord and King Rivers between October to February. Within the Adelaide, South Alligator and East Alligator Rivers, animals have been captured in November and May, May and February and June, respectively. The specimen captured off the Wessel Islands was captured in November. 9. Give details of the distinctiveness and detectability of the species See section 1.5 for more details. The most distinctive characteristic of Glyphis is their large second dorsal fin. Any sharks captured in rivers and estuaries which have a high second dorsal fin (one half to three fifths the height of the first dorsal fin) should be photographed and reported to the nearest museum. Reproduction 10. For plants: When does the species flower and set fruit? What conditions are needed for this? What is the pollinating mechanism? If the species is capable of vegetative reproduction, a description of how this occurs, the conditions needed and when. Does the species require a disturbance regime (e.g. fire, cleared ground) in order to reproduce? For animals: provide overview of breeding system and of breeding success, including: when does it breed; what conditions are needed for breeding; are there any breeding behaviours that may make it vulnerable to a threatening process? There is no data on the reproductive biology of Glyphis sp. A. Four sexually mature Glyphis sp. C have been recorded and represent the only data available for this genus. Glyphis sp. C apparently mature at a smaller size than Glyphis sp. A. Two mature male Glyphis sp. C were 141 and 142 cm TL, whereas four Glyphis sp. A between 147 and 157 cm TL were not sexually mature based on non calcified claspers. A 177 cm TL female Glyphis sp. C captured on the 17 October 2003 was sexually mature and had 9 early stage embryo’s and associated yolk sac within the uterus. A 252 cm female Glyphis sp. C captured on the same location long line had recently pupped as determined by the distended uteri. These data suggest that pupping occurs prior to the wet season. The lack of yolky ova in the ovaries of both these sharks suggests that Glyphis only breeds every second

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year. As in other Carcharhinids, the reproductive mode is placental viviparity with females giving birth to live young. Based on data from one Glyphis sp. C litter size is expected to be around 9. Size at birth is probably between 50 – 60 cm TL. As with other euryhaline elasmobranchs, pupping most likely occurs at river mouths or within estuaries. The juveniles moving upstream after birth to escape predation from larger sharks.

Feeding 11. Summarize the species’ food items or sources and timing/seasonality Glyphis sp. A feed primarily on bony fish. Stomachs have contained pieces of king salmon (Eleutheronema tetradactylum) in specimens captured in King Sound (Thorburn and Morgan, 2004) and in Joseph Bonaparte Gulf. Specimens captured in Joseph Bonaparte Gulf had up to 100 small stingray spines imbedded in the musculature and cartilage of the mouth indicating that stingrays are an important dietary item. An unidentified catfish (Arius sp.) was also found in the stomach of animal captured in Joseph Bonaparte Gulf. 12. Briefly describe the species’ feeding behaviours, including those that may make the species vulnerable to a threatening process There is no data on the feeding behaviour of Glyphis sp. A, however given the turbidity of the water this species is found in, it is likely that vision is of little use to this species. Instead, sharks are most likely capturing prey using elaborate ampullary electroreceptor system to detect the prey’s low-frequency bioelectric field (see Hueter et al., 2004).

Movements 13. Describe any relevant daily and seasonal pattern of movement for the species, including relevant arrival/departure dates if migratory There are no data on movement patterns of this species. 14. Give details of the species’ home ranges/territories There is no data on the species home range. Other 15. Is there other information that relates to the survival of this species that you would like to address? N/A

Section 3 – References, referees Reference list Branstetter, S and Stiles, R (1987). Age and growth estimates of the bull shark, Carcharhinus leucas, from the northern Gulf of Mexico. Environmental Biology of Fishes 20(3):169-181. Compagno, LJV and Cook SF. (1995). The exploitation and conservation of freshwater elasmobranchs: status of taxa and prospects for the future. p 62-90. In: The biology of freshwater elasmobranchs. Asymposium to honor Thomas B. Thorson. Eds: M Oetinger and GD Zorzi. Journal of Aquariculture & Aquatic Sciences, Volume 7.

Compagno, LJV & Niem, VH (1998). Carcharhinidae. In Carpenter, K.E. & Niem, V.H. (eds) ‘FAO Species Identification Guide for Fishery Purposes. The Living Marine Resources of the Western Central

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Pacific. Volume 2. Cephalopods, crustaceans, holothurians and sharks’. Food and Agriculture Organization of the United Nations, Rome, pp. 1312-1360.

Hazon, N, Wells, A, Pillans, RD, Good, JP, Anderson, WG, Franklin, CE (2003). Urea based osmoregulation and endocrine control in elasmobranch fish with special reference to euryhalinity. Comp. Biochem. Physiol. 136B, 685-700. Heuter, RE, Mann, DA, Maruska, KP, Sisneros, JA and Demski, LS (2004). Sensory biology of elasmobranchs, in Biology of sharks and their relatives. JC Carrier, JA Musick and MR Heithaus, eds. CRC Press, New York, 326 – 368. Larson, HK (2002). Report to Park Australia on Estuarine Fish Monitoring of Kakadu National Park, Northern Australia, Australia, Musuem and Art Gallery of the Northern Territory, Darwin, 51 pp. Last, PR. (2002). Freshwater and estuarine elasmobranchs of Australian. Elasmobranch Biodiversity Conservation and Management. Proceedings of the International seminar and workshop, Sabah, Malaysia, July 1997. Occasional Paper IUCN Species Survival Commission. Eds SL Fowler, TM Reed and FA Dipper. Pp 185 – 192. Last, PR. and Stevens, JD. (1994). Sharks and rays of Australia. C.S.I.R.O. Australia, 513 pp + 84 colour plates. Morgan, D, Allen, M, Bedford, P and Horstman, M (2004). Fish fauna of the Fitzroy River Western Australia - including the Banuba, Gooniyandi, Ngarinyin, Nyikina and Walmajarri Aboriginal names. Records of the Western Australian Museum, 22: 147 - 161 Pillans, RD, Franklin, CEF (2004). Plasma osmolyte concentrations and rectal gland mass of bull sharks, Carcharhinus leucas, captured along a salinity gradient. Comp. Biochem. Physiol. 138A, 363-371. Pillans, RD, Good, JP, Anderson, WG, Hazon, N, Franklin, CEF (2005). Freshwater to seawater acclimation of juvenile bull sharks (Carcharhinus leucas): plasma osmolytes and Na+/K+-ATPase activity in gill, rectal gland, kidney and intestine. J. Comp. Physiol. B, 175: 37-44. Pogonoski, JJ, Pollard, DA and Paxton, JR (2002). Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. Natural Heritage Trust, Environment Australia, 375 pp. Tanaka, S (1991). Age estimation of freshwater sawfish and sharks in northern Australia and Papua New Guinea. The University Museum, University of Tokyo, Nature and Culture No.3: 71-82. Tanuichi, T and Shimizu, M (1991). Elasmobranchs collected from seven river systems in Northern Australia and Papua New Guinea. The University Museum, University of Tokyo, Nature and Culture No. 3: 3-10. Thorburn, DC and Morgan, DL (2004). The northern river shark Glyphis sp. C (Carcharhinidae) discovered in Western Australia. Zootaxa 685: 1 – 8. Thorburn, DC., Peverell, S., Stevens, JD., Last, PR. and Rowland, AJ. (2003). Status of freshwater and estuarine elasmobranchs in northern Australia. Final Report to Natural Heritage Trust. 75 pp.

Winter, SP, Dudley, SFJ, Kistasamy, N, Everett, B (2002). Age and growth estimates for the Zambezi shark, Carcharhinus leucas, from the east coast of South Africa. Marine and Freshwater Research 53: 557 – 566.

Dated: Has this document been refereed? If so, indicate who: No

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Appendix 1.6.1. Summary of all records of Glyphis sp. C collected in Australia to date.

Date Species State Location TL (cm) Salinity 15-Oct-03 Glyphis sp. C WA King Sound 142 15-Oct-03 Glyphis sp. C WA King Sound 177 17-Oct-03 Glyphis sp. C WA King Sound 251 Oct-03 Glyphis sp. C NT Joseph Bonaparte Gulf Oct-03 Glyphis sp. C NT Joseph Bonaparte Gulf Oct-03 Glyphis sp. C NT Joseph Bonaparte Gulf Oct-03 Glyphis sp. C NT Joseph Bonaparte Gulf 09-Jun-03 Glyphis sp. C WA King Sound 135 32.1 09-Jun-03 Glyphis sp. C WA King Sound 119 32.1 07-Jun-03 Glyphis sp. C WA Doctors Creek - King Sound 91 33.2 09-Jun-03 Glyphis sp. C WA King Sound 142 32.1 09-Jun-03 Glyphis sp. C WA King Sound 102 32.1 06-Jun-03 Glyphis sp. C WA Doctors Creek - King Sound 96 33.4 01-Jun-02 Glyphis sp. C WA Doctors Creek - King Sound 99 36.6 11-Apr-03 Glyphis sp. C WA King Sound 20 11-Apr-03 Glyphis sp. C WA King Sound 21 11-Apr-03 Glyphis sp. C WA King Sound 21 16-Nov-02 Glyphis sp. C NT Adelaide River, NT (about 100 km upstream) 108 10 15-Nov-02 Glyphis sp. C NT Adelaide River, NT (about 80 km upstream) 58 10 25-Feb-01 Glyphis sp. C NT East Alligator River 80 10-Jun-99 Glyphis sp. C NT East Alligator River 121 7.6 24-Dec-02 Glyphis sp. C WA Ord River 80 27-Oct-03 Glyphis sp. C WA Ord River 73 27-Oct-03 Glyphis sp. C WA Ord River 75 27-Oct-03 Glyphis sp. C WA Ord River 80 19-Jan-04 Glyphis sp. C WA Ord River 80 26-May-89 Glyphis sp. C NT Adelaide River, NT (about 100 km upstream) 131 0 10-May-96 Glyphis sp. C NT South Alligator River

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Section 1 – Conservation Assessment Information required for assessing species nominated as threatened under the EPBC Act. Answer all parts, indicating when there is no information available. Taxonomy 1. What are the currently accepted scientific and common name/s for the species? Note any other scientific names that have been recently used Pristis microdon Latham, 1794 freshwater sawfish Local synonyms: Pristiopsis leichhardti Whitley, 1945 Other common names: Leichhardts sawfish, smalltooth sawfish, great-tooth sawfish, largetooth sawfish 2. Is this species conventionally accepted? If not, explain why. Is there any controversy on the taxonomy? Further investigation into the taxonomy of Pristis microdon in northern Australia and elsewhere in its range is required. The relationships between the Australian freshwater sawfish and two other similar species that also enter freshwater, Pristis pristis and P. perotteti, need to be established (Last and Stevens 1994; Compagno and Cook 1995). The original description of Pristis microdon did not give a locality, but most authors have used the name Pristis microdon for the Indo-West Pacific sawfishes of this species group as contrasted from the Atlantic Pristis perotteti and the eastern Pacific Pristis zephyreus. Compagno and Cook (1995) suggested the following working arrangement until more conclusive systematic studies of the pristids could be carried out. Pristis microdon of the Indo-West Pacific is recognised as distinct from P. pristis and P. perotetti of the Atlantic and P. zephyreus of the eastern Pacific is considered a junior synonym of P. perotetti, and P. leichhardti of Australia a junior synonym of P.microdon. There is some evidence suggesting disparity in the size at maturity of P. microdon suggesting there may be more than one species. A 2 m male freshwater sawfish in a Hong Kong aquarium (collected from Australia) was sexually mature, while a 3.7 m male specimen in a Paris aquarium was immature(P Last, CSIRO Marine Research, personal communication). 3. Describe any cross-breeding with other species in the wild, indicating how frequently and where this occurs None known. Legal status 4. What is the species’ current conservation status under Australian and State/Territory Government legislation? Commonwealth Environment and Protection Biodiversity Act 1999 (EPBC): Vulnerable

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Territory Parks & Wildlife Conservation Act 2000: Data Deficient Queensland State legislation: Vulnerable Non-legislative Listing 2000 IUCN Red List: Endangered (global) and Critically Endangered (south east Asia) Australian Threatened & Potentially Threatened Marine & Estuarine Fishes: Critically Endangered (Pogonoski et al. 2002) Australian Society For Fish Biology List of Australian Threatened Fishes: Potentially Threatened Description 5. Give a brief description of the species’: appearance, including size and/or weight, and sex and age variation if appropriate; social structure and dispersion (e.g. solitary/clumped/flocks) A medium-sized slender sawfish with 18-23 (mainly 20-22) evenly-spaced rostral teeth, a distinct lower lobe to the caudal fin (much less than half the length of the upper lobe), with broad based pectoral fins and a first dorsal fin origin well in advance of the pelvic fin origins. As in other sawfish, the body is shark-like, the pectoral fins distinct and the head flattened with a blade-like snout or saw and the gill openings are on the ventral surface. The pectoral fins are broadly triangular in shape with a straight hind margin. The dorsal fins are tall and pointed. The lower caudal fin lobe is significantly less than half the length of the upper lobe. The rostral teeth start near the saw-base and each tooth has a groove along its posterior margin. Freshwater sawfish generally have a yellowish, to greyish body with a white ventral surface, the outer margins of the fins are a richer yellowish brown (Last and Stevens 1994). Thorburn et al. 2004 noted a large degree of colour variation in juvenile individuals collected from riverine environments in northern Australia; the trunks of individuals collected further inland from clear waters were often a deepish green, and sometimes almost black. Specimens from Telegraph Pool on the Fitzroy River (Western Australia) were lighter green or yellow/brown. In Australia, the freshwater sawfish is the largest fish found in freshwater where specimens up to 280 cm TL have been recorded (Thorburn et al. 2004). A 582 cm TL female has been recorded from the marine environment in Queensland (Peverell, James Cook University, unpublished MSc thesis) and elsewhere this species is reputed to reach 700 cm TL (Last and Stevens 1994). FishBase (2002) records indicate a maximum size of 656 cm TL (Compagno and Last 1999) and maximum weight of 600kg (Stehman 1981).As with most elasmobranchs, females appear to reach a greater size than males. The mean TL and weight of five specimens from the Embley area of Queensland was 354 cm and 171.2 kg (Giles et al., CSIRO Marine Research, unpublished report); these authors provide a length-mass-relationship shown in Figure 1. Figure1. Length-mass relationship for Pristis microdon.

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The female to male sex ratio of 48 specimens from the Fitzroy River, Western Australia, was 1.5:1 (29 females, 19 males). Tanaka (1991), in a preliminary ageing study of P. microdon based on analysis of bands in the vertebrae, suggested an immature male of 247.3 cm TL was 16 years old and that the largest specimen he examined (361.1 cm mature male) was 44 years old. Tanaka (1991) generated the following von Bertalanffy growth parameters from back-calculated and

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observed data, respectively: L∞ = 398 cm, K = 0.047, t0 = -5.54; L∞ = 363 cm, K = 0.066, t0 = -4.07. Peverell (James Cook University, unpublished MSc thesis) examined vertebral bands on 41 specimens from inshore Queensland waters and found a faster growth rate suggesting maturity could be attained at 7-8 years of age and longevity was about 35 years. His von Bertalanffy growth parameters from back-calculated and observed data, were respectively: L∞ = 589 cm, K = 0.08, t0 = -1.84; L∞ = 632 cm, K = 0.08, t0 = -1.72. The growth rate from observed data was 56 cm in the first year and 17 cm TL in the fifth year. Growth rates may be greater in captivity; a specimen in the Territory Wildlife Park grew from 60 to 260 cm in three years (Wilson 1999), and a specimen currently in captivity has grown from 86 cm to 150 cm, a rate of 64 cm in under a year (L. Squire, Cairns Marine Aquarium Fish, personal communication). A tagged individual at liberty for four months in the Fitzroy River, Western Australia, grew 3 cm from 215 to 218 cm TL (Thorburn et al. 2004). There is no published information on the social structure of P. microdon. However, while catch records of adults are usually of single animals, small groups of juveniles are sometimes caught together (Thorburn et al. 2003; our unpublished data). This may reflect aggregation in nursery areas, and as the juveniles appear to occur mainly in freshwater it may also be a reflection of more restricted habitat, such as in isolated pools, during the dry season. Published information on dispersion is very limited. Thorburn et al. (2004) suggest that the King Sound, Western Australia, (and the rivers that flow into it) may act as the only nursery areas for this species in the region, with mature animals radiating out from this area following the coastline in inshore marine waters, and perhaps returning to this locality to breed or pup. These authors also report the capture of two large individuals (3.5 m female and 3 m mature male) in coastal waters south of King Sound and note this provides some support for the idea that mature individuals move out of the rivers and remain offshore, and then move back to the rivers to pup. Peverell (James Cook University, unpublished MSc thesis) also notes that catch data from Queensland supports the idea that individuals of 6+ years probably inhabit offshore waters. Pupping may occur in the tidal reaches of rivers with the pups subsequently dispersing upstream and into the floodplains in the wet season (Thorburn et al. 2004). The modification of river flows through irrigation schemes and the construction of weirs and causeways may act as barriers restricting the movement of juvenile sawfish (Peverell ,James Cook University, unpublished MSc thesis). 6. Identify major studies on the species Whitley 1945; Merrick and Schmida 1984; Shimizu and Taniuchi 1991; Last and Stevens 1994; Thorburn et al. 2003, 2004; Peverell (James Cook University, unpublished MSc thesis); Giles et al. (CSIRO Marine Research, unpublished report). International context (for species that are distributed both inside and outside Australia’s jurisdiction) 7. Describe the species’ global distribution Coastal and riverine environments of northern Australia. Elsewhere uncertain; confirmed from several major river basins of Indonesia and New Guinea, but also north to Borneo, the Philippines and Viet Nam and possibly west to India. The similar, if not conspecific Pristis perotteti, occurs in the tropical and subtropical Atlantic, eastern Pacific and southwestern Indian Oceans (Last and Stevens 1994). India; Ganges and Bramapurtra Rivers. Thailand; possibly from Mae Nam Chaophraya River at Nantauri and above Paknam. Malaysia; Perak River and possibly Tembeling and Linggi Rivers. Cambodia; Grand Lac. Philippines; Lake Naujan, Mindoro. Indonesia; Indragiri River near Rengat. Sumatra; Bandjermassing. Borneo; Kinabatangan River. Papua New Guinea; Fly River system, Sepik River, Laloki River, Lake Murray. Inhabits sandy or muddy bottoms of shallow coastal waters, estuaries, river mouths and freshwater rivers and lakes. Adults are usually found in estuaries and coastal areas, and the juveniles in fresh water. 8. Give an overview of the global population’s size, trends, threats and security of the species outside Australia No quantitative data are available on global population size of P. microdon. There is a distinct lack of data on the biology of Pristis spp with important parameters such as age and size at maturity, reproductive periodicity and lifespan being largely unknown. It is likely that due to the large size attained by sawfish that they are long lived, produce few young and mature late in life. These “k-selected” life history traits combined with a heavily toothed rostrum that makes sawfish particularly vulnerable to capture in gill net and trawl fisheries results in sawfish being extremely prone to overfishing. This vulnerability to overfishing is highlighted by the fact that all four species are listed under the IUCN Red List of Threatened Species as Endangered globally with Pristis microdon listed as Critically Endangered within South East Asia (Giles et al., CSIRO Marine Research, unpublished report)

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From interviews carried out with communities on the Kinabatangan River and in Labuk Bay in Sabah, Borneo, villagers indicated a downward trend in sawfish captures. They remembered them as abundant in the 1970s, declining sharply in the 1980s and most of them could not catching any since then (Manjaji 2002). In North and South America, there is increasing evidence that sawfish populations have suffered severe declines in range and abundance. Large toothed sawfish Pristis perotetti were once common in Lake Nicaragua and Thorson (1982a) reported that during the late 1960s the sawfish population in the lake was “in the hundreds of thousands”. However, heavy fishing pressure driven by markets for the fins and flesh resulted in massive population declines by the late 1970s and 1980s leading Thorson (1982b) to comment that “sawfish had virtually disappeared from the lake”. Recent surveys of Lake Nicaragua by Taniuchi (2002) suggest that sawfish are “close to extinction in Lake Nicaragua” (Giles et al., CSIRO Marine Research, unpublished report). The small toothed sawfish Pristis pectinata once ranged from the Gulf of Mexico to North Carolina and is now restricted to a few remote areas in the Florida Keys Everglades national park that are protected from fishing. It is estimated that the U.S. population has declined by 99% due to capture in gillnets and trawls. In 2003, the small toothed sawfish was listed by the National Marine Fisheries Service (NMFS) as Endangered under the U.S. Endangered Species Act. This landmark decision was the first to protect a marine fish in U.S. waters (Giles et al., CSIRO Marine Research, unpublished report). Pristid fins are highly sought after in the international shark fin trade (Rose and McLoughlin 2001), and escalating prices in this trade are cause for grave concern to all species in this family. Within the Indo-West Pacific, anecdotal reports suggest sawfish populations have declined drastically in the last 15-20 years (Giles et al., CSIRO Marine Research, unpublished report) 9. Explain the relationship between the Australian population and the global population, including:

g. What percentage of the global population occurs in Australia; h. Is the Australian population distinct, geographically separate or does part or all of the population move in/out

of Australia’s jurisdiction (give an overview; details in Movements section); i. Do global threats affect the Australian population?

Relationships between Australian and global populations of P.microdon are complicated by uncertainties of whether Atlantic, eastern Pacific and southwestern Indian Ocean populations (currently recognized as a separate species Pristis perotetti) are in fact synonymous with P. microdon (see sections 1.2 & 1.7). Australian populations of P. microdon appear to be still relatively healthy (particularly in Western Australia) and are likely to comprise a high proportion of the global population. In view of the likely (generally) restricted movements of pristids, it is probable that the Australian population can be considered geographically separate, certainly in a management sense. There is almost certainly some genetic exchange with south east Asian populations, but this would only require movement of one or two individuals per generation to result in genetic homogeneity. Fishing in other parts of their range is unlikely to impact on Australian populations. However, global threats such as the international fin trade may impact on local stocks by encouraging foreign poaching close to the Australian coast as evidenced recently by Indonesian vessels. High fin prices may also encourage illegal Australian fishing. National context Distribution 10. Describe the species’ distribution in Australia and, if available, attach a map Known from several drainage systems in northern Australia in fresh or weakly saline water: the Fitzroy, Durack, Robinson and Ord Rivers (Western Australia), the Adelaide, Victoria, Daly, East Alligator, Goomadeer, Roper, McArthur, Wearyan and Robinson Rivers (Northern Territory), and the Gilbert, Mitchell, Normanby, Wenlock, Mission, Embley and Leichhardt Rivers (Queensland). There are coastal records (many of them unvalidated) from Queensland, Northern Territory and Western Australia, including one individual captured off Cape Naturaliste, southern Western Australia (R. McAuley, Fisheries WA, personal communication). There are no other Australian records of this species outside the tropics. This species was encountered in 12 of the 39 river/creek systems sampled between the Fitzroy River in Western

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Australia and Normanby River in Queensland (Thorburn et al. 2004). It was captured near river mouths, such as the Robinson River (Western Australia), and also encountered several hundred kms from the sea, such as at Elsey Station on the Roper River and Geike Gorge (over 350 km from the sea) on the Fitzroy River. Additional data collected by Morgan et al. (2002) indicated the presence of this species in Margaret River Gorge (a tributary of the Fitzroy River), over 400 km inland. 11. What the extent of occurrence (in km2) for the species (described in Attachment A); explain how it was calculated and datasets used

g. What is the current extent of occurrence? h. What data is there to indicate past declines in extent of occurrence (if available, include data that indicates

the percentage decline over the past 10 years or 3 generations whichever is longer)? i. What data is there to indicate future changes in extent of occurrence (if available, include data that indicates


Northern Western Australia, Northern Territory and Queensland north of about 200 S, including river systems as mentioned in section 1.10. However, it is currently unclear how far offshore their distribution extends. One vagrant was recorded recently from off Cape Naturaliste, southern Western Australia, at about 340 S (see section 1.10). While there are few quantitative species-specific data on sawfish abundance in Australia, their numbers appear to have declined drastically along the east coast with sawfish now virtually extinct in New South Wales and South East Queensland. Anecdotal reports from recreational fishers as far north as Townsville suggest that P. microdon were once “very common” in the Ross River but over the past 10-15 years have not been recorded. Information from a number of recent projects suggest that sawfish populations in some areas (such as the Kimberley region of Western Australia) are still healthy while in other regions populations have been fished down. Resulting information also suggests that sawfish have very specific habitat requirements, and that there is an urgent need to understand these requirements to be able to interpret abundance estimates and population status. Pristid bycatch from the Queensland Shark Program comprises a large dataset over about 30 years of beach meshing around major Queensland population centres during the summer months; although species identifications or biological data are lacking. These data show a clear decline in sawfish catch from 1970-1990 (Figure 1.11.1), over which period the fishing effort was relatively constant (Giles et al., CSIRO Marine Research, unpublished report).

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Figure 1.11.1. Catches of unidentified pristids from Cairns, Townsville and Rockhampton in the Queensland Beach Control Program (1969 – 2003). Catches include data from nets and drum lines. These data were provided by Queensland Department of Primary Industries and Fisheries Service. 12. What is the area of occupancy (in km2) for the species (described in Attachment A; explain how calculated and datasets that are used)

g. What is the current area of occupancy? h. What data is there to indicate past declines in area of occupancy (if available, include data that indicates the

percentage decline over the past 10 years or 3 generations whichever is longer)? i. What data is there to indicate future changes in area of occupancy (if available, include data that indicates


North of 200 S in northern Australia. It is unclear whether there are discontinuities in the coastal distribution within this area of occupancy. It is also unclear whether the lack of records from certain river systems within their area of occupancy (Thorburn et al. 2004) reflects a real absence or merely poor sampling effort. There are no quantitative species-specific data on declines; for general comments see section 1.11. 13. Is the species’ distribution severely fragmented? Why? Severely fragmented refers to the situation in which increased extinction risk to the taxon results from most individuals being found in small and relatively isolated subpopulations (in certain circumstances this may be inferred from habitat information). These small subpopulations may go extinct, with a reduced probability of recolonization. Anecdotal information suggests that population numbers are severely reduced through fishing and habitat destruction in south east Asia, and elsewhere in its distribution. During recent extensive market sampling surveys that involved

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CSIRO Marine Research in the Philippines, Borneo and Indonesia, only two pristids were encountered (one each in Borneo and Indonesia). This suggests that outside Australia their populations may now be severely fragmented. Populations within Australia, particularly in Western Australia, appear to be still relatively healthy and may represent the last stronghold for the species. 14. How many locations do you consider the species occurs in and why? The term 'location' defines a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the species present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a species is affected by more than one threatening event, location should be defined by considering the most serious plausible threat. There are insufficient data to determine this (see sections 1.7 and 1.10-13). Habitat 15. Give a brief description of the species’ habitat/s (Details entered in Section 2) Pristis microdon inhabits sandy or muddy bottoms of shallow coastal waters, estuaries, river mouths and freshwater rivers and lakes. Adults are usually found in estuaries and coastal areas, and the juveniles in fresh water. Most of the rivers in which it occurs fragment into a series of pools in the dry season, reducing its available habitat (Last 2002). Captures of P. microdon by Thorburn et al. (2004) were made in the main channels, larger tributaries and in backwaters, in lower, middle and upper riverine reaches. It was most commonly encountered over finer substrates, such as sand and silt and was usually caught in a deeper section of a river adjacent to a sand or silt shallow, such as a sandbar or shallow backwater. Capture sites ranged in depth from 0.7-6 m and it was encountered in both tidal and non-tidal reaches with generally low flow rates. Pristis microdon was mainly collected from fresh or low salinity water (<10 ppt). However, one site on the Robinson River (Western Australia)) was 35 ppt. This site also had the highest turbidity (secchi disc reading of 5 cm) and temperature (32.5oC), and the lowest levels of dissolved oxygen (4.3 mgL-1) of any site at which the species was collected. Although it was found in both turbid and clear water, capture sites were generally clear, and had relatively high dissolved oxygen levels. Taniuchi and Shimizu (1991) recorded P. microdon from 0-25 ppt in northern Australian and New Guinean rivers. Populations 16. What is the species’ total population size in terms of number of mature individuals? Are there other useful measures of population size and what are they? In the absence of figures, terms such as common, abundant, scarce can be of value. Not known. See general comments on population trends in section 1.8. 17. Does the species occur in a number of smaller populations? How many? If available, for each population give the locality, numbers and trends in numbers and tenure of land (if available) (include extinct populations). Can these be considered to be subpopulations and why? Subpopulations are defined as geographically or otherwise distinct groups in the population between which there is little demographic or genetic exchange (typically one successful migrant individual or gamete per year or less). Given the likely generally restricted dispersion abilities of pristids, populations in different major geographical regions (such as northern Australia, south east Asia etc) can probably be considered as separate. See comments in sections 1.8 and 9. 18. What is the population trend for the entire species?

e. What data is there to indicate past decline in size (if available, include data on rate of decline over past 10 years or 3 generations whichever is longer)?

f. What data is there to indicate future changes in size (if available, include data which will indicate the percentage of decline over 10 years or 3 generations whichever in longer (up to a maximum of 100 years in the future) where the time period is a continuous period that may include a component of the past)?

No species-specific quantitative data on population trends are available. For general trends see sections 1.8 and 1.11. 19. Does the species undergo extreme natural fluctuations in population numbers, extent of occurrence or area of occupancy? To what extent and why? Extreme fluctuations can be said to occur in a number of taxa when population size or distribution area varies widely, rapidly and frequently,

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typically with a variation greater than one order of magnitude (i.e. a tenfold increase or decrease). Not known, but unlikely as chondrichthyan life-history strategies provide more stable recruitment patterns than for teleost fish. 20. What is the generation length and how it is calculated? Generation length is the average age of parents of the current cohort (i.e. newborn individuals in the population). Generation length therefore reflects the turnover rate of breeding individuals in a population. Generation length is greater than the age at first breeding and less than the age of the oldest breeding individual, except in taxa that breed only once. Where generation length varies under threat, the more natural, i.e. pre-disturbance, generation length should be used. About 20 years, based on preliminary age and growth estimates by Peverell (James Cook University, unpublished MSc thesis), and at least 35 years based on an earlier study by Tanaka (1991). Peverell’s data suggests age at first maturity may be as early as 7-8 years, and that for this species to reach 95% of its maximum growth it would have a longevity of 33 years. In an earlier preliminary study, Tanaka (1991) suggested a much slower rate of growth with the oldest specimen he aged being 46 years (361cm TL) and a 16 year old specimen (247 cm) still being immature. Neither of these studies validated the periodicity of the vertebral bands they used for ageing. Survey effort 21. Has the species been reasonably well surveyed? Provide an overview of surveys to date and the likelihood of its current known distribution and/or population size being its actual distribution and/or population size There have been few dedicated surveys for Indo-Pacific P. microdon, or freshwater elasmobranchs in general. Compagno (2002) summarises freshwater and estuarine elasmobranch surveys in the Indo-Pacific region and comments on threats, distribution and speciation. Manjaji (2002) provides some information from Sabah, Malaysian Borneo and Taniuchi (2002), Taniuchi and Shimizu (1991), Ishihara et al. (1991) and Last (2002) provide some information on P. microdon caught in research surveys in Papua New Guinea and northern Australia. Thorburn et al. (2003) summarise freshwater fish surveys in northern Australia that identified elasmobranchs including P. microdon (Table 1.21.1), and carried out a broad, field-based survey of freshwater elasmobranchs in northern Australia. In six months of field work, they surveyed 137 sites within 39 river/creek systems in Western Australia, the Northern Territory and Queensland covering some 30,000 km during the project. Thorburn et al. (2004), provided information on elasmobranchs in the Fitzroy River, Western Australia, including P. microdon. While some individual freshwater systems containing P. microdon have probably not been documented, the general recorded geographic distribution is probably a true reflection of the species actual distribution. As noted in section 1.8, there are no quantitative data on population size for this species. Table 1.21.1 (from Thorburn et al. 2003): Previous Australian records of freshwater sharks and rays. Records for each species include author, year, State/Territory and river in which they were recorded. WA- Western Australia, NT- Northern Territory, Qld- Queensland.

Author Year Glyphis sp. Glyphis sp. A Glyphis sp. C P. microdon H. chaophraya Whitley 1945 NT: no river

specified (P.leichhardti)1

Midgley (in Larson 1999)

1981 NT: Keep

McPherson pers.comm.2.

1983 Qld: Bizant

Bishop et al. 1986

1986 NT: Alligator Rivers (P.leichardti)

Taniuchi et al. 1991

1989 NT: Adelaide, West Alligator

NT: Daly Qld: Gilbert

NT: Daly

Johnson pers.comm.3

1991 Qld: Norman

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Larson 1999 1999 NT: Keep Larson 2000 1999 NT: East,

West , South Alligator

Berra pers comm. 4

2001 NT: Adelaide NT: Adelaide

Morgan et al. 2002 5

2002 WA: Fitzroy WA: Fitzroy

Hyland pers.comm. 6

2001 Qld: Normanby

Last 2002 2002 Qld: Bizant NT: South Alligator

WA: Ord, Pentecost NT: Alligator Qld: Gilbert

Squires pers.comm. 7

2003 Qld: Flinders, Norman, Wenlock

Qld: Wenlock

1. P. leichardti is now considered synonymous with P. microdon 2. Geoff McPherson, Fisheries Biologist, Northern Fisheries Centre, Qld Department of Primary Industries. 3. Jeff Johnson, Fish Section, Queensland Museum. 4.Tim Berra, Professor Emeritus, Dept. of Evolution, Ecology & Organismal Biology, The Ohio State University 5. From a project studying barramundi, and other fish fauna in the Fitzroy River by Dr David Morgan (Murdoch University) that collaborated with this NHT study. The findings were first presented in Morgan et al. 2002, and contain data collected during the current study. 6. Stuart Hyland, Fisheries Biologist, Northern Fisheries Centre, Qld Department of Primary Industry 7. Lyle Squires, Cairns Marine Aquarium Fish Threats 31. Identify past, current and future threats, to the species indicating whether they are actual or potential. For each threat, describe:

g. how and where it impacts on this species h. what its effect has been so far (indicate whether it is known or suspected; present supporting

information/research; does it only affect certain populations) i. what is its expected effect in the future (is there supporting research/information; is the threat only suspected;

does it only affect certain populations) Global threats to sawfishes and to freshwater elasmobranchs in general have been summarised by Compagno and Cook (1995). These authors note that the observations of Thorson (1976, 1982, 1987) were the first to raise conservation concerns over this group of fish. Compagno and Cook (1995) list habitat destruction and pollution, as well as overfishing, resulting from rapid human population growth in the Twentieth Century particularly in the undeveloped countries as the major threats. They cite examples of industrial and agricultural toxic waste on the Indian subcontinent, destruction of rainforest for agriculture, mining and construction in South and Central America, the timber industry in south east Asia, water impoundments and hydropower in Central America, and the impact of human wars such as the Viet Nam War of 1964 and the 1991 Gulf War. Compagno and Cook (1995) point out that while euryhaline elasmobranchs like P. microdon may be less vulnerable than obligate freshwater species, they are generally restricted to warm inshore marine environments such as bays, estuaries, lagoons and near beaches when they are not in fresh water. Species in these environments are readily accessible to low technology but increasingly intensive artisanal and small commercial fisheries, and to the effects of coastal development and degradation. They may also need to reproduce in freshwater, which may become a limiting factor. Unfortunately, there have been virtually no quantitative surveys carried out to determine the impacts of these threats.

While the level of threats in Australia are much less than in most undeveloped countries, habitat degradation, pollution and overfishing are still impacting on sawfish populations. Compagno and Cook (1995) note the potential impact of uranium mining in Kakadu, Northern Territory, where several of the adjacent river systems have populations of P. microdon. Peverell (James Cook University, unpublished MSc thesis) and Thorburn et al. (2004) note the potential

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impacts of habitat modification, with the latter authors noting the example of the Camballin weir on the Fitzroy River, Western Australia, that results in the aggregation of P. microdon directly below the weir. Thorburn et al. (2003) note the threat of recreational fishing on P. microdon in freshwater systems reporting 12 dead specimens (some of which had fishing line and hooks attached) on the banks of one of their sampling sites at Telegraph Pool, Fitzroy River. More dead specimens were recorded on their return to this site three weeks later. Bowhunting, a form of recreational hunting, is mentioned by Truelove (2003) as a potential threat as pristids are classed as an ‘award species’ for this activity-group. Truelove (2003) provided some information on the traditional utilisation of freshwater pristids, and they may represent a valuable, traditional source of food. Pristids have very high cultural and religious importance to some communities and there may be cultural restrictions on who can take them, limited to particular times and places. Some communities may use pristids as food for ceremonial purposes and McDavitt (1996) gives a brief account of some of the tribal mythologies and cultures relating to pristids among communities in Central America, West Africa and Papua New Guinea, noting that in some societies sawfish have powerful totemic meaning. Pristid rostra are used for ceremonial purposes by indigenous people (Environment Australia 1998) and there are anecdotal reports that indigenous people in the Weipa and Karumba area are buying sawfish rostra from commercial fishers. The rostra are then painted and the end product put onto the tourist market in Cairns (Truelove 2003). Giles et al. (CSIRO Marine Research, unpublished report) reviewed commercial and recreational catch records for sawfish, including P. microdon, from a wide range of methods and available datasets in northern Australia. They noted that the information base on sawfish distribution and abundance could be greatly improved by accessing the large amount of knowledge and experience possessed by commercial fishers, particularly in the Northern Prawn Fishery and inshore net fisheries. They examined a number of research and commercial datasets over the last 30 years for sawfish records, which had not been fully explored previously for this purpose. Commonwealth and State commercial fisheries likely to capture sawfish were identified in a previous risk assessment of elasmobranch vulnerability in northern Australian waters (Stobutzki et al., 2003), based on fishing methods and spatial distribution of effort. These fisheries were treated as the primary possible sources for logbook and/or observer data, and included those from demersal and semi-pelagic trawl, demersal and surface set gillnet, and hook and line fisheries. Some pelagic trawl and longline fisheries not included in the previous study, on the basis of the demersal habit of sawfish, were found to include a small number of sawfish records and were also included. Historical commercial fisheries likely to have caught sawfish, and live-collection licences were also targeted as data sources. The coverage of northern commercial fisheries with possible sawfish take documents the main areas of bycatch, but was not exhaustive; some fisheries were not considered due to the difficulty of obtaining data and because of time constraints. Recreational catch of sawfish is very difficult to quantify, the emphasis necessarily focusing on available anecdotal evidence. Rostra mounted on the walls of fishers’ homes and in public establishments are testament to a long history of catch in northern Australia, extending into the fairly recent period of history before fishing licences and gear restrictions were introduced in Australia’s north. An attempt was made to gather any available data and/or rostra dimensions from fishing clubs where sawfish are known to occur, and data sourced from previous research on recreational fisheries. Records in museum collections are often originally from the recreational sector. Research catch data for sawfish were gathered from CSIRO for all voyages in northern Australian waters, and for all collaborative projects for which data were available. Visits were made to a number of museums to gather catch records and measure and photograph sawfish remains. Other research organisations were contacted for any available information. Availability of contextual effort data varied considerably, and catch rates were calculated on a dataset basis wherever possible. For the commercial fisheries, fishing effort data necessary for the calculation of catch rates was not generally available. For the majority of the research datasets, sawfish catch was consistently recorded, in which case fishing events (shots, hauls etc) where sawfish were not caught were also incorporated into the database to allow the calculation of dataset catch-rates. All non-catch records in the database are mapped alongside catch in the respective research dataset descriptions. The species identifications in this report are those originally recorded, and only corrected where there are ambiguities and intention is clear (e.g. saw shark vs. sawfish in Northern Territory), or where later verification was possible.

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The majority of records in the database were obtained from State agencies; primary Northern Territory logbooks and Queensland’s beach meshing program. State observer data made a very small contribution to the overall number of State records, and is presently the only data source for sawfish bycatch in Western Australia and Queensland fisheries. After the State fisheries, the most data were collected from historical fisheries, the Northern Prawn Fishery and research surveys, followed by collections, a small number from the aquarium trade, and miscellaneous reports. The majority of catch data from these fisheries are not species-specific, and are contained in the main CSIRO Marine Research report by Giles et al. that is appended with these conservation assessment templates. The main data pertaining to P.microdon are summarized below. In the Commonwealth Northern Prawn Fishery, 448 sawfish were recorded from 1998-2003 of which only two (0.6%) were recorded as P. microdon. In the Northern Territory commercial fishery logbook data, 1858 sawfish were recorded between 1994-2003. No species-specific data are available from the logbooks, and there is only very limited observer coverage. As logbooks do not itemise sawfish in Queensland fisheries, only a small number of commercial records were available from their CFISH database (combined weight/boat day) and these records were not itemised by fishery. A small amount of scientific observer records were available for the Queensland Inshore Net Fishery. Sawfish bycatch from the Queensland Shark Control Program (QSCP) contributes a large dataset from about thirty years of beach meshing around major Queensland population centres during the summer months; although these data are not species-specific. The QSCP dataset shows a clear decline in sawfish catch from 1970 to 1990 (Appendix 2, figure 1), over which period effort was relatively constant (N. Gribble, Northern Fisheries Centre, personal communication). Detailed data were available for a number of sawfish captured under an aquarium trade license, and some anecdotal information was gathered from an ex-operator in the same region. There are also around 250 high detail records from QDPI observer studies in the N3 and N9 fisheries (Peverell, QDPIF, Northern Fisheries Centre, personal communication). Logbook data are not available for Western Australia’s commercial fisheries as sawfish are not itemised. North Western Australian fisheries cover a large expanse of remote coastline which is likely to support the healthiest populations of sawfish in Australian waters. A small amount of scientific observer data are available for some fisheries. The Taiwanese Pelagic Gillnet Fishery (TPGF) operated surface set gillnets in northern Australian waters from 1974 until 1986. Fishing took place offshore from the North West Shelf to Cape York, with effort centring on the area north of the Wessel Islands from the AFZ limit to 12 nautical miles from the coast. Sawfish recorded as a catch component in the AFZ logbooks were confined to three short periods on respective vessels in 1982 and 1984. Thirty pristids were recorded from one vessel between the 3rd and 29th June 1982, four between 1st February and 14th March 1984 by another vessel and 31 between 16th April and 13th September 1984 by another vessel. Length frequency data on sawfish catch were collected by the AFZ Observers, covering 389 sets, around 2% of the total gillnet sets (Stevens & Davenport 1991), and about half of the specimens were recorded to species. No P. microdon were recorded. The Taiwanese pair trawl fishery operated from 1971 to the early 1990s, from about 26ºS, 112ºE east to 136ºE and north to 8ºS. AFZ logbook data show that the majority of pristid records (94%) were part of what appears to be a continuous record of sawfish over a 3 month period when one vessel caught 306 individuals between 10th September and 16th November 1984. Interpreting these data as a continual record of sawfish catch operating at 3.4 shots per day, as used for previous NPF calculations (CSIRO Marine Research, unpublished data), more than one sawfish was captured per shot over this 96 day interval. Daily catch was highly variable, with sawfish appearing in 69.5% of shots (at 3.4 shots/day); two sawfish or more in 32% of shots, and one sawfish captured in 37% of shots over the period. Fishing was concentrated over the area north of the Wessel Islands and Cape Arnhem, and sawfish were caught in depths of 27-96 m. Only 12 pristids were recorded from limited coverage of both the Taiwanese longline and Soviet trawl fisheries in northern Australia. As there were 748 trawls where no pristids were noted, this strongly suggests they were not normally recorded.

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From CSIRO research datasets on the North West Shelf, one pristid was caught from 279 FV Courageous trawls between 1978-79, and 12 pristids from 1750 RV Soela trawls from 1979-89. However, many of these trawls, particularly by FV Courageous were in midwater and thus unlikely to catch pristids. Of the 12 specimens caught by RV Soela, none were identified as P. microdon. The FV Rachel conducted pelagic gillnetting surveys in near shore environments off the north coast of Australia in 1984 and 1985. Of the 26 pristids caught, three were P. microdon. Fish surveys run by CSIRO at Embley, Karumba, Groote Eyland and Albatross Bay in the Gulf of Carpentaria between 1986-1996 caught 33 pristids of which 13 were P. microdon. A summary of the data by gear type shows that net fishing accounts for most of the catch records in the database (80.2%), followed by trawling (16.6%), line (9.2%) and recreational gears (0.3%) The overwhelming majority of data (79.7%) are recorded at the family level. Of pristids recorded at the species level, 14.8% were P.microdon. Anoxypristis cuspidata were found primarily offshore, with Pristis spp. dominating inshore catch. Small numbers of P .zijsron and P .microdon were recorded offshore, and some A .cuspidata were recorded in inshore habitats. Records available for sawfish catch in Australian waters have greatly increased in number and diversity of sources in recent years, due to increasing efforts to monitor this group. The earliest sawfish records acquired in the study are museum specimens, with a small number of records distributed fairly evenly from 1883 to 1960. Records compiled from Australian fisheries begin with the start of the QSCP beach meshing in 1963. Research datasets provide data from around 1980, with historical fisheries contributing a large number of records in the early 1980s. The least number of records are available for the early to mid 1990s, with a reduction in sawfish captures in the QSCP, before the recording of sawfish became routine in the Northern Territory fisheries and NPF, and elasmobranch observer programs began in most northern fisheries. With the bias of the dataset toward more recent records, evidence that pristids as a group have decreased in abundance in northern Australia must be derived from analysis of catch rates calculated with comparative spatial and temporal distribution of effort. This has not been attempted in this report. See also sections 1.8 and 1.9 32. If not included above, identify catastrophic threats, i.e. threats with a low predictability that are likely to severely affect the species - Identify the threat, explain its likely impact and indicate the likelihood of it occurring (e.g. a drought/cyclone in the area every 100 years) See section 1.31 for regional threats outside Australia relating to habitat degradation that, in the absence of controls, could devastate local populations in riverine or inshore coastal habitats. Within Australia, sufficient controls on development and overfishing exist to hopefully prevent large-scale catastrophic declines. 33. Identify and explain any additional biological characteristics particular to the species that are threatening to its survival (e.g. low genetic diversity)? Identify and explain any models addressing survival of the specie. Not known. No genetic studies of genetic diversity have been carried out for P. microdon (or other sawfish species). Threat abatement and recovery 34. Identify key management documentation available for the species, e.g. recovery plans, conservation plans, threat abatement plans. Department of the Environment and Heritage Draft Recovery Plan for P. microdon in Australia (2003). Bycatch Action Plans and Strategic Assessments for Australian Fisheries. IUCN Red List of Threatened Species, FAO International Plan of Action for Sharks, Australian National Action Plan for Sharks. See also section 1.4 35. Give an overview of how threats are being abated/could be abated and other recovery actions underway/proposed. Identify who is undertaking these activities and how successful the activities have been to date The Commonwealth of Australia developed a National Bycatch Policy in 1999 and a Commonwealth Bycatch Policy in 2000. The National Policy restricts its attention to non-target discard species and non-target organisms affected by fishing gear, and does not include byproduct.

The Commonwealth Policy commits to prepare Bycatch Action Plans for all major Commonwealth fisheries. Plans for

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the Northern Prawn Fishery and the Torres Strait Prawn Fishery were implemented in 1999.

Turtle exclusion devices (TEDs) and bycatch reduction devices (BRDs) have been trialled in the Northern Prawn Fishery since 1993 and became compulsory in this fishery in 2000. Trials to improve their performance through modifications are continuing. Projects are currently under way to evaluate the effectiveness of these devices, in collaboration with the fishing industry.

A project by the Bureau of Rural Sciences, CSIRO and AFMA is monitoring the catch of sea turtles in the Northern Prawn Fishery. Results from these projects show that the use of TEDs and BRDs has resulted in a substantial decline in the catches of large animals such as turtles, stingrays and sharks. Sawfish are less likely to be effectively excluded by BRDs, however, some limited preliminary information suggests a 50% reduction in pristids and a 79% reduction in A. cuspidata (D. Brewer, CSIRO Marine Research, personal communication).

The effects of Commonwealth fisheries on some non-target threatened species, such as albatrosses and turtles, had been assessed under previous legislation and these assessments and their listings have been carried over to the EPBC Act. Some fishing methods are recognised as 'key threatening processes' under the EPBC Act. Regulations were issued in February 2001 placing very specific obligations on longlining operations under the Threat Abatement Plan for the incidental catch of seabirds during oceanic longlining fishing operations. This Plan was developed in cooperation with the fishing industry. A nomination for otter trawling for marine turtles is being considered for listing.

The Commonwealth Government has provided funds from the Natural Heritage Trust to establish the SeaNet extension service. The project is focused on increasing the rate of adoption by the commercial fishing sector of new fishing gear and practices to aid bycatch reduction and to implement environmental best practice.

The States and the Northern Territory have also been addressing bycatch in different ways. Western Australia and the Northern Territory have adopted the National Policy. Action plans or management plans for fisheries are being prepared in three States and the Northern Territory on a priority basis. The use of bycatch reduction devices (BRDs) in two estuarine prawn trawl fisheries in New South Wales has been made mandatory, to save large quantities of juvenile fish. In Queensland, New South Wales and Western Australia, the recording of bycatch is currently being considered for compulsory inclusion in management plans. However, there has been little or no response to the assessment or management of the non-target retained species (byproduct) in relation to either the effects on the species or the effects on the ecosystems.

In response to information demonstrating that sawfish are at “high risk” from commercial gillnetting, the NT Joint Authority Shark Fishery has established a voluntarily ‘no take’ status for all sawfish, encouraging all commercial fishers to release live sawfish. Due to the difficulty in releasing large live sawfish, combined with high value fins; it is uncertain whether this initiative will prove effective. The compliance of commercial operators is currently being assessed via log book (David McKee, NTDBIRD, pers. comm.).

36. Which populations are in reserve systems? Which of these are actively managed for this species? Give details Marine Reserves, National Parks and other protected areas provide some protection for freshwater and coastal populations of P. microdon in Australia. Examples are the Cobourg Marine Park, Kakadu and Lichfield National Parks and the Milingimbi Crocodile Island, Glyde River area and Castlereagh Bay/Howard Island areas in the Northern Territory, and areas of the Great Barrier Reef Marine Park in Queensland. However, none of these areas are actively managed for P. microdon.

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Section 2 – Recovery, Conservation, Protection Additional information on legal status 1. Does the species have legal protection under other legislation or political agreements, e.g. Convention on International Trade in Endangered Fauna and Flora (CITES),Convention on Migratory Species (CMS) No, a proposal to list pristids on CITES has to date been unsuccessful; not listed on CMS. Additional information on distribution 2. Give locations of: captive/propagated populations; populations recently re-introduced to the wild; and sites for proposed population re-introductions. Note if these sites have been identified in recovery plans Some P. microdon, captured in Australia, are held in Australian and overseas aquariums such as at Osaka, Kaiyukan, Singapore, Hong Kong, the USA, Genoa, Shanghai and Seoul (Truelove 2003). Cairns Marine Aquarium Fish have a permit for collecting sawfish in northern Australia. Additional information on habitat 3. Describe the specie’ non-biological habitat (e.g. aspect, topography, substrate, climate) and biological habitat (e.g. forest type, associated species, sympatric species). If the species uses different habitats for different activities (e.g. breeding, feeding, roosting, dispersing, basking), then describe each habitat Juveniles of P. microdon mainly inhabit freshwater habitats, while the adults appear to occur in inshore coastal waters. Pupping may occur in estuarine waters with the neonates then traveling up the rivers. Specific details of mating or pupping areas are not known. See sections 1.5 and 1.15 for more details on habitat of this species 4. Does the species use refuge habitat, e.g. in times of fire, drought or flood? Describe this habitat Available freshwater habitat will vary with the season, expanding to flood plains during the wet season and being restricted in some cases to isolated pools in the dry season. 5. Is the species part of, or does it rely on, a listed threatened ecological community? Is it associated with any other listed threatened species? In some regions, including areas of northern Australia, P. microdon occurs with the Commonwealth EPBC listed speartooth and northern river sharks Glyphis spp. It may also co-occur with the green sawfish Pristis zisjron that is classified as Endangered by the IUCN Red List 2003 and listed as an Endangered Species in New South Wales waters under the Fisheries Management Act 1994. Additional information on population 6. Provide details on ages of sexual maturity, life expectancy and natural mortality Peverell (James Cook University, unpublished MSc thesis) examined vertebral bands on 41 specimens from inshore Queensland waters and suggesting sexual maturity could be attained at 7-8 years of age and longevity was about 35 years. Interpolating from the data of Tanaka (1991), in an earlier study also based on analysis of vertebral rings, maturity was at around 20 years and longevity about 50 years or more (see section 1.5). There are no published estimates of natural mortality. 7. Identify important populations necessary for the species’ long-term survival and recovery? This may include: key breeding populations, those near the edge of the species’ range or those needed to maintain genetic diversity In a global context, northern Australia (particularly Western Australia) may have some of the only relatively healthy populations of P. microdon (and other pristids) remaining. Survey methods 8. Describe methods for detecting species including when to conduct surveys (e.g. season, time of day, weather conditions); length, intensity and pattern of search effort; and limitations and expert acceptance; recommended methods; survey-effort guide Pristids, including P. microdon, are vulnerable to most types of fishing gear including nets (particularly gillnets and

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demersal trawls) and hooks. In coastal areas they are readily captured by commercial trawl and gillnets, as well as longlines. In freshwater areas they are most easily captured in gillnets, but are also vulnerable to longlines. Recreational hook and line fishing is also effective, particularly in restricted freshwater areas. The timing of freshwater surveys will depend on the area, but in most tropical environments will be restricted during the wet season, with best access during the dry season. Four-wheel drive vehicles and small boats are required to access many rugged and remote areas. Sampling should include a range of habitats from the coastal marginal zone, tidal feeder creeks, main channels, tributaries and waterholes. Permission to sample from the relevant land-owners and management authorities may be required. A combination of 30 m (2.5 m drop) monofilament gill net panels, of 10, 15 and 20 cm stretched mesh are often suitable in riverine habitats. The number of panels used at each site will be determined by factors such as the channel width and the density of snags. Gill net set-times will depend on factors such as catch rate and tidal influence. Nets should be checked at intervals depending on the amount of bycatch present; at sites with high bycatch nets should be checked every hour. When nets are set overnight, only larger mesh sizes should be used to minimise by-catch. In most cases key priorities should be to avoid mortality and minimise stress to the target species, and to reduce bycatch of other species. Approval for the capture of live animals for research should be obtained from Animal Ethics, committees. Gill nets can be anchored to run at right angles to the river bank or set parallel to it when the flow rate is high. At sampling sites where there is excessive tidal influence, gill netting should be conducted at periods of slow and slack water. Sinking long-lines of about 40 m length can be set at right angles to river banks. Suitable construction is 250 kg nylon main line, with a maximum of 20 4/0 all rounder and/or tuna circle hooks, spaced approximately 2 m apart. Each hook is connected to the main line via a shark clip and 70 kg trace. Any commonly available bait can be used, such as catfish (Ariidae spp) or mullet (Mugilidae spp). During transit in shallow waters, or while surveying from the riverbanks, freshwater elasmobranchs can occasionally be observed. These animals can be pursued and captured with the use of a throw net (Thorburn et al. 2003). 9. Give details of the distinctiveness and detectability of the species See section 1.5. Pristis microdon can be easily confused with other pristids and a reliable key (such as in Last and Stevens 1994) should be used by the inexperienced to confirm identifications. Distinctive characters of P. microdon are 18-23 evenly spaced rostral teeth, a distinct lower lobe on the caudal fin and the first dorsal fin situated well forward of the pelvic fins. Reproduction 10. For plants: When does the species flower and set fruit? What conditions are needed for this? What is the pollinating mechanism? If the species is capable of vegetative reproduction, a description of how this occurs, the conditions needed and when. Does the species require a disturbance regime (e.g. fire, cleared ground) in order to reproduce? For animals: provide overview of breeding system and of breeding success, including: when does it breed; what conditions are needed for breeding; are there any breeding behaviours that may make it vulnerable to a threatening process? Little is known about reproduction in P. microdon. As in other pristids, the reproductive mode is aplacental viviparity with lecithotropic nutrition of the embryos (energy reserves come from the egg). Pristids have some of the largest ova sizes in the chondrichthyes. Litter size in other pristids is up to 20. Size at birth and at maturity in P. microdon appears to be about 50 cm and 3 m TL, respectively. However, a specimen in a Hong Kong aquarium was mature at 200 cm (P Last, CSIRO Marine Research, personal communication). Pupping may occur in estuarine areas with juvenile distribution mainly restricted to freshwater and adults in coastal habitats. In the Mitchell River (western Cape York Peninsula, Queensland), pupping apparently occurs at the beginning of the wet season in November or December (Allen 1991). Preliminary results of micro-chemistry work on specimens caught in the Gulf of Carpentaria suggests gestation occurs in the marine or estuarine environment (Peverell, James Cook University, unpublished MSc thesis). At birth the rostrum is well developed but soft and flexible, and covered by a firm membranous sheath (Merrick and Shimida). Breeding frequency is unknown, but the closely related P. perotteti is believed to breed every second year (Thorson 1976). There are no known records of P. microdon being bred in captivity (Camhi et al. 1998). Specimens in Sea World (US)

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have shown mating behaviour (L. Squire, Cairns Marine Aquarium Fish, personal communication). See also section 1.5.

Feeding 11. Summarize the species’ food items or sources and timing/seasonality Generally, pristids are bottom feeders taking a variety of fish, mollusks and crustaceans (Merrick and Shimida 1984). The saw may be used to rake through the substratum or to stun schooling fishes with sideswipes of the snout. Specimens of P. microdon collected for aquaria from the Gulf of Carpentaria region have had barramundi, saratoga and jewfish (Protonibea diacanthus) scales on the rostrum; the size of scales suggests they may feed on quite large fish. In the Flinders River, Queensland, they have been observed congregating to eat freshwater prawn (Macrobrachium rosenbergii), and have been taken by fishers also targeting freshwater prawns using cast nets (L. Squire, Cairns Marine Aquarium Fish, personal communication). Anecdotal information indicates that they feed at night. 12. Briefly describe the species’ feeding behaviours, including those that may make the species vulnerable to a threatening process See section 2.11.

Movements 13. Describe any relevant daily and seasonal pattern of movement for the species, including relevant arrival/departure dates if migratory Other than postulated movements associated with reproduction (see sections 1.5 and 1.11) little is known about migration. Thorburn et al. (2004) tagged 25 P. microdon ranging in length from 81.5-277.0 cm TL in the Fitzroy River, Western Australia. Of 12 tagged in the early dry season, one was recaptured near its release location in the middle reaches of the Fitzroy late in the dry season. Tagging has also been carried out by Peverell (James Cook University, unpublished MSc thesis) in Queensland. 14. Give details of the species’ home ranges/territories Not known, other than information presented in section 1.5. Other 15. Is there other information that relates to the survival of this species that you would like to address?

Section 3 – References, referees Reference list Allen, GR (1991). Field Guide to Freshwater Fishes of New Guinea. Publication No. 9 of the Christiansen Research Institute, Madang, PNG.

Camhi, M, Fowler, S., Musick, J, Brautigam, A and Fordham, S. (1998). Sharks and their Relatives. Ecology and Conservation. Occasional Paper of the IUCN Species Survival Commission no. 20, 39 pp.

Compagno, LJV. (2002). Freshwater and estuarine elasmobranch surveys in the Indo-Pacific region: threats, distribution and speciation. p. 168-180. In: Fowler, S.L., Reed, T.M. and Dipper, FA. (eds). Elasmobranch Biodiversity, Conservation and Management: Proceedings of the International Seminar and Workshop, Sabah, Malaysia, July 1997. IUCN SSC Shark Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. xv + 258 pp.

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Compagno, LJV and Cook SF. (1995). The exploitation and conservation of freshwater elasmobranchs: status of taxa and prospects for the future. p 62-90. In: The biology of freshwater elasmobranchs. Asymposium to honor Thomas B. Thorson. Eds:M Oetinger and GD Zorzi. Journal of Aquariculture & Aquatic Sciences, Volume 7.

Compagno, LJV and Last, PR (1999). Family Pristidae: Sawfish. In: Carpenter, KE and Niem, V (eds). FAO Identification guide for fishery purposes. The Living Marine Resources of the Western Central Pacific. FAO, Rome Environment Australia (1998). Advice to the Minister for the Environment and Heritage from the Endangered Species Scientific Subcommittee (ESSS) on a proposal to add a species to Schedule 1 of the Endangered Species Protection Act 1992 (the ACT) – Pristis microdon. http://www.biodiversity.environment.gov.au/plants/threaten/lists/changes…/Fwsawfish.ht FishBase (2002). FAO http://www.fishbase.org Ishihara, H, Taniuchi, T and Shimizu, M. (1991). Sexual dimorphism in number of rostral teeth in the sawfish, Pristis microdon, collected from Australia and Papua New Guinea. The University Museum, University of Tokyo, Nature and Culture No.3: 83-89. Last, PR. (2002). Freshwater and estuarine elasmobranchs of Australia. In: Fowler, S.L., Reed, T.M. and Dipper, FA. (eds). Elasmobranch Biodiversity, Conservation and Management: Proceedings of the International Seminar and Workshop, Sabah, Malaysia, July 1997. IUCN SSC Shark Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. xv + 258 pp. Last, PR. and Stevens, JD (1994). Sharks and rays of Australia. C.S.I.R.O. Australia, 513 pp + 84 colour plates. Manjaji, BM. 2002. New records of elasmobranch species from Sabah. pp 70-77. In: Fowler, S.L., Reed, T.M. and Dipper, FA. (eds). Elasmobranch Biodiversity, Conservation and Management: Proceedings of the International Seminar and Workshop, Sabah, Malaysia, July 1997. IUCN SSC Shark Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. xv + 258 pp. McDavitt, M (1996). The cultural and economic importance of sawfishes (family Pristidae). Shark News 8 Newsletter of the IUCN/SSC Shark Specialist Group Merrick, JR and Shimida, GE (1984). Australian Freshwater Fishes. Biology and management. Griffin Press, South Australia, 409 pp. Morgan, D, Allen, M, Bedford, P and Horstman, M. (2002). Inland fish fauna of the Fitzroy River Western Australia, including the Bunuba, Gooniyandi, Ngarinyin, Nyikina and Walmajarri Aboriginal names. Report to the Natural Heritage Trust: 56 pp. Peverell, SC. Sawfish (Pristidae) of the Gulf of Carpentaria, Queensland, Australia. James Cook University. Unpublished MSc thesis. Pogonoski, JJ, Pollard, DA and Paxton, JR (2002). Conservation Overview and Action Plan for Australian Threatened and Potentially Threatened Marine and Estuarine Fishes. Natural Heritage Trust, Environment Australia, 375 pp.

Rose, C and McLoughlin K (2001). Review of Shark Finning in Australian Fisheries. Final report to the Fisheries Resources Research Fund. Bureau of Rural Sciences. 166 pp.

Shimizu, M and Taniuchi, T (1991). Eds: Studies on elasmobranches collected from seven river systems in northern Australia and Papua New Guinea. The University Museum, University of Tokyo, Nature and Culture No.3: 109 pp. Stehman, M (1981). Pristidae. In Fischer, W., Bianchi, G. and Scott, WB (eds). FAO Species Identification Sheets for Fishery Purposes Eastern Central Atlantic.

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Stevens, JD, and Davenport, SR (1991). Analysis of catch data from the Taiwanese gill-net fishery off northern Australia, 1979-1986. CSIRO Marine Laboratories Report 213, 51 pp Stobutzki, I, Stevens, JD, Miller, M, Salini, J, Jones, P, Deng, R, Fry, G, Taranto, T (2003) The Sustainability of Northern Australian Sharks and Rays: Final report to Environment Australia. Tanaka, S (1991). Age estimation of freshwater sawfish and sharks in northern Australia and Papua New Guinea. The University Museum, University of Tokyo, Nature and Culture No.3: 71-82.

Tanuichi, T (2002). Outline of field surveys for freshwater elasmobranchs conducted by a Japanese research team. P. 181-184. In: Fowler, S.L., Reed, T.M. and Dipper, FA. (eds). Elasmobranch Biodiversity, Conservation and Management: Proceedings of the International Seminar and Workshop, Sabah, Malaysia, July 1997. IUCN SSC Shark Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. xv + 258 pp.

Tanuichi, T and Shimizu, M (1991). Elasmobranchs collected from seven river systems in Northern Australia and Papua New Guinea. The University Museum, University of Tokyo, Nature and Culture No. 3: 3-10. Thorburn, DC, Peverell, S, Stevens, JD, Last, PR. and Rowland, AJ (2003). Status of freshwater and estuarine elasmobranchs in northern Australia. Final Report to Natural Heritage Trust. 75 pp.

Thorburn, D, Morgan, DL, Rowland, AJ and Hill, H (2004). Elasmobranchs in the Fitzroy River, Western Australia. Report to the Natural Heritage Trust, 29 pp.

Thorson, TB (1982a). Life history implications of a tagging study of largetooth sawfish, Pristis perotetti, in the Lake Nicaragua-Rio San Juan system. Environmental. Biology of Fishes. 7: 207 -228 Thorson, TB (1982b). The impacts of commercial exploitation on sawfish and shark populations in Lake Nicaragua. Fisheries 7: 2 – 10 Thorson, TB (1976). Observations on the reproduction of the sawfish, Pristis perotteti, in Lake Nicaragua, with recommendations for its conservation. In: Investigations of the ichthyofauna of Nicaraguan lakes (Ed. TB Thorson). University of Nebraska-Lincoln. p 641-650. Thorson, TB (1987). Human impacts on shark populations. In: Sharks an inquiry into biology, behaviour, fisheries and use. (Ed. SF Cook). Oregon Sea Grant Publication EM8330. Oregon State University, Corvallis. p. 31-37. Truelove, K (2003). Draft freshwater sawfish (Pristis microdon) Recovery Plan. Department of the Environment and Heritage, unpublished report. 51 pp. Wilson, D (1999). Freshwater sawfish Pristis microdon. Australian New Guinea Fishes Association's A-Z Notebook of Native Freshwater Fish. ANGFA Bulletin 41. Whitley, GP (1945). Leichhardt’s sawfish. Australian Zoologist 11 (1): 1-41. Dated: Has this document been refereed? If so, indicate who: No.

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Section 1 – Conservation Assessment Information required for assessing species nominated as threatened under the EPBC Act. Answer all parts, indicating when there is no information available. Taxonomy 1. What are the currently accepted scientific and common name/s for the species? Note any other scientific names that have been recently used

Pristis zijsron Bleeker, 1851 (green sawfish)

2. Is this species conventionally accepted? If not, explain why. Is there any controversy on the taxonomy?

Yes.

Pristis zysron is an older spelling (Pogonoski et al. 2002)

3. Describe any cross-breeding with other species in the wild, indicating how frequently and where this occurs

Not known to occur

Legal status 4. What is the species’ current conservation status under Australian and State/Territory Government legislation? EPBC Act: not listed. (Nominated as “Vulnerable” but this was rejected as there was insufficient data to demonstrate that it was likely to become endangered within the next 25 years)

NT Parks & Wildlife Conservation – Vulnerable.

NSW Fisheries Management Act 1994 – Endangered.

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Description 5. Give a brief description of the species’: appearance, including size and/or weight, and sex and age variation if appropriate; social structure and dispersion (e.g. solitary/clumped/flocks)

Pristis zijsron is greenish-brown/olive above and pale/whitish below. It is a large, robust sawfish with ventral gill openings and it has 24-28 pairs of unevenly-spaced teeth, starting from the rostral base. The first dorsal fin origin is slightly behind the pelvic fin origin and the lower lobe of the caudal fin is much shorter than half the length of the upper lobe (Last and Stevens, 1994).

Pristis zijsron reaches 500cm total length in Australia (Last and Stevens, 1994). The growth curve below is taken from Peverell (James Cook University, unpublished MSc thesis) and is based on limited samples, but is the best information available for the species.

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Figure 1.5.A von Bertalanffy growth curve fitted to observed age estimates from 18 vertebral sections and back calculated lengths for Pristis zijsron (sexes combined).

6. Identify major studies on the species

Cavanagh Rachel, D. (ed.); Kyne, Peter, M. (ed.); Fowler, Sarah, L. (ed.); Musick, John A. (ed.); Bennett, Michael B. (ed). (2003). The Conservation Status of Australian Chondrichthyans: Report of the IUCN Shark Specialist Group Australia and Oceania Regional Red List Workshop. The University of Queensland, School of Biomedical Sciences, Brisbane, Australia. X+ 170pp.

Giles, J., Pillans, R., Miller, M. and Salini, J. (2004). Sawfish catch data in northern Australia: a desktop study. Report produced for FRDC Project 2002/064 Northern Australian Sharks and Rays: the sustainability of target and bycatch fisheries, phase 2.

Peverell, S C (2005). Distribution of sawfishes (Pristidae) in the Queensland Gulf of Carpentaria, Australia, with notes on sawfish ecology. Environmental Biology of Fishes, (in press).

Peverell, S C (James Cook University, unpublished MSc thesis) Sawfish (Pristidae) of the Gulf of Carpentaria, Queensland, Australia, James Cook University, unpublished MSc Thesis.

Thorburn, DC., Peverell, S., Stevens, JD., Last, PR. and Rowland, AJ. (2003). Status of freshwater and estuarine elasmobranchs in northern Australia. Final Report to Natural Heritage Trust. 75 pp.

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International context (for species that are distributed both inside and outside Australia’s jurisdiction) 7. Describe the species’ global distribution

Widely distributed in the northern Indian Ocean to South Africa, and off Indonesia and Australia. (Last & Stevens 1994). However, based mainly on anecdotal reports, the current distribution is severely reduced due to fishing pressure and anthropomorphic coastal habitat changes.

8. Give an overview of the global population’s size, trends, threats and security of the species outside Australia

Pristis zijsron has not been recorded within fish markets of Eastern Indonesia during the current ACIAR Sharks and Rays of Eastern Indonesia projects despite over 160 visits to 11 markets from Jakarta to Kupang (CSIRO Marine Research, Unpublished data).

No quantitative data are available on global population size of P. zijsron. There is a distinct lack of data on the biology of Pristis spp with important parameters such as age and size at maturity, reproductive periodicity and lifespan being largely unknown. It is likely that due to the large size attained by sawfish that they are long lived, produce few young and mature late in life. These “k-selected” life history traits combined with a heavily toothed rostrum that makes them particularly vulnerable to capture in gill net and trawl fisheries results in sawfish being extremely prone to overfishing. This vulnerability to overfishing is highlighted by the fact that all four species are listed under the IUCN Red List of Threatened Species as Endangered globally. From interviews carried out with communities on the Kinabatangan River and in Labuk Bay in Sabah, Borneo, villagers indicated a downward trend in sawfish captures. They remembered them as abundant in the 1970s, declining sharply in the 1980s and most of them could not catching any since then (Manjaji 2002). In North and South America, there is increasing evidence that sawfish populations have suffered severe declines in range and abundance. Large toothed sawfish Pristis perotetti were once common in Lake Nicaragua and Thorson (1982a) reported that during the late 1960s the sawfish population in the lake was “in the hundreds of thousands”. However, heavy fishing pressure driven by markets for the fins and flesh resulted in massive population declines by the late 1970s and 1980s leading Thorson (1982b) to comment that “sawfish had virtually disappeared from the lake”. Recent surveys of Lake Nicaragua by Taniuchi (2002) suggest that sawfish are “close to extinction in Lake Nicaragua” The small toothed sawfish Pristis pectinata once ranged from the Gulf of Mexico to North Carolina and is now restricted to a few remote areas in the Florida Keys Everglades national park that are protected from fishing. It is estimated that the U.S. population has declined by 99% due to capture in gillnets and trawls. In 2003, the small toothed sawfish was listed by the National Marine Fisheries Service (NMFS) as Endangered under the U.S. Endangered Species Act. This landmark decision was the first to protect a marine fish in U.S. waters (Giles et al., CSIRO Marine Research, unpublished report). Pristid fins are highly sought after in the international shark fin trade (Rose and McLoughlin 2001), and escalating prices in this trade are cause for grave concern to all species in this family. Within the Indo-West Pacific, anecdotal reports suggest sawfish populations have declined drastically in the last 15-20 years (Giles et al., CSIRO Marine Research, unpublished report) 9. Explain the relationship between the Australian population and the global population, including:

j. What percentage of the global population occurs in Australia; k. Is the Australian population distinct, geographically separate or does part or all of the population move in/out

of Australia’s jurisdiction (give an overview; details in Movements section); l. Do global threats affect the Australian population?

a. Anecdotal information suggests that this species Indo-West Pacific distribution has been severely impacted by anthropogenic factors. The available catch records indicate that it is virtually extinct in most of South East Asia, and that northern Australia may be the last region where there are significant populations of P. zijsron.

b. In view of the likely (generally) restricted movements of pristids, it is probable that the Australian population can be considered geographically separate, certainly in a management sense. There is almost certainly some genetic exchange with South East Asian populations, but this would only require movement of one or two

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individuals per generation to result in genetic homogeneity.

c. Yes. Foreign fishing incursions now occur within sight of the Australian coast and it is possible that P. zijsron from Australian waters are caught by illegal Indonesian fishers. These fishers are mainly after fins and most likely take sawfishes as part of their catch. This issue will be addressed in a CSIRO Marine Research shark fin identification proposal (May 2005).

National context Distribution 10. Describe the species’ distribution in Australia and, if available, attach a map

Pristis zijsron is distributed from about Cairns north to Shark Bay in Western Australia. It has been recorded in inshore coastal environments, as well as estuaries and river mouths in slightly reduced salinities ,but it does not penetrate into freshwater. There are also records of animals far offshore in up to 70 m of water (CSIRO Marine Research, unpublished data). Their current distribution is significantly less than 40-60 years ago when they were found in NSW and Southern Queensland. Records of P. zijsron from the last 100 years are presented in Figure 1.10.1. This figure shows records of this species along the east coast of Queensland and NSW prior to the 1960s, but not records south of Cairns after this period. Little is known about their historical distribution in Western Australia and the Northern Territory, although given these areas are less populated than the east coast it is likely that sawfish have not undergone declines of the same magnitude.

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Figure 1.10.1. Records of 92 P. zijsron in Australia from 1912 – 2004. Data were collected from museums, research surveys and fisheries observers (see Giles et al., unpublished report).

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11. What the extent of occurrence (in km2) for the species (described in Attachment A); explain how it was calculated and datasets used

j. What is the current extent of occurrence? k. What data is there to indicate past declines in extent of occurrence (if available, include data that indicates

the percentage decline over the past 10 years or 3 generations whichever is longer)? l. What data is there to indicate future changes in extent of occurrence (if available, include data that indicates


a. Northern Western Australia, the Northern Territory and Queensland north of about 200 S. There are a few records of this species in trawls from well offshore. See Figure 1.10.1 for extent of occurrence. Given the sporadic nature of the records for P. zijsron, it not possible to place an area value to their extent of occurrence.

b. A good sequence of data are available from the Queensland Shark Control Program (QSCP) and indicates a total disappearance of all sawfish in recent times in southern regions (see Figure 1.11.1). These data represent a continuos sampling effort at the same location throughout the year for over 40 years and provide the best long term dataset available for pristids. It is important to note that the captures in the shark nets are a minor source of mortality for this species, but they do represent the only time-series of abundance for sawfish in Australia. There are over 1400 gill net licences in Queensland, and these have probably contributed to the long term decline in these species. In NSW P. zijsron is listed as Critically Endanged, however it is quite probably already extinct there with no records of this species in the last 20 years (Nick Otway, Fisheries Research Institute, Cronulla, personal communication).

c. Given the evidence from the QSCP data, it is likely that P. zijsron will disappear from populated regions of the Queensland east coast. Unless fishing effort is reduced or capped in more remote areas of Queensland, Western Australia and the Northern Territory, the species is likely to progressively disappear where there is heavy fishing pressure.

The increased demand for shark and shark products will place additional pressure on sawfish population in remote areas. This is not restricted to the Australian shark fishery, but includes impacts by the escalating foreign shark fishing presence in the Gulf of Carpentaria and elsewhere in the north. John Salini (CSIRO Marine Research) has Coastwatch data on illegal shark fishing vessels from the past four years (2001, 2002, 2003, 2004) which shows a significant increase in illegal shark fishing very close to Australia. The recent arrest of 27 foreign vessels (escorted to Gove) is clear evidence of this increase in shark fishing effort.

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12. What is the area of occupancy (in km2) for the species (described in Attachment A; explain how calculated and datasets that are used)

j. What is the current area of occupancy? k. What data is there to indicate past declines in area of occupancy (if available, include data that indicates the

percentage decline over the past 10 years or 3 generations whichever is longer)? l. What data is there to indicate future changes in area of occupancy (if available, include data that indicates


a. The state of the catch data is such that this question cannot be answered in a meaningful way. Gillnetting fishers do not always record sawfish ‘interactions’ and hence this creates large gaps in the coastal distribution map. The data from the QSCP clearly shows a dramatic decline in catches of all sawfishes from Cairns to the Gold Coast, with literally no sawfish recorded for many years.

The same factors influencing extent of occurrence are influencing area of occupancy (See section 1.11 for further comments)

13. Is the species’ distribution severely fragmented? Why? Severely fragmented refers to the situation in which increased extinction risk to the taxon results from most individuals being found in small and relatively isolated subpopulations (in certain circumstances this may be inferred from habitat information). These small subpopulations may go extinct, with a reduced probability of recolonization.

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Given the even distribution of P. zijsron throughout northern Australia (Figure 1.10.1), the species distribution does not appear to be severely fragmented. Gaps in their distribution on Figure 1.10.1 are likely to be a result of inadequate surveys in remote regions of Western Australia.

14. How many locations do you consider the species occurs in and why? The term 'location' defines a geographically or ecologically distinct area in which a single threatening event can rapidly affect all individuals of the species present. The size of the location depends on the area covered by the threatening event and may include part of one or many subpopulations. Where a species is affected by more than one threatening event, location should be defined by considering the most serious plausible threat.

Pristis. zijsron appears to have a uniform distribution throughout northern Australia and there are no data to suggest the population is fragmented. However, it is clear that this species has suffered severe restrictions in range. See sections 1.7 and 1.10 - 13 Habitat 15. Give a brief description of the species’ habitat/s (Details entered in Section 2)

Pristis zijsron occurs in near shore coastal environments including estuaries, river mouths, embayments and along sandy and muddy beaches. They have been recorded in very shallow water (less than 1 m) to offshore trawl grounds in over 70 m of water. Data from animals captured in Australia by gill nets (predominantly inshore) and prawn and fish trawls (predominantly offshore) (Figure 1.15.1) suggests that smaller P. zijsron (<2.5 m TL) are more common in inshore environments while larger animals (> 2.5 m TL) are likely to be captured both inshore and offshore.

Figure 1.15.1. Proportion of catch records for P. zijsron taken in commercial trawls and gill nets (n=47). Information on the short term habitat usage of a 3.5 m female P. zijsron tracked in Port Musgrave, Queensland were obtained by Peverell and Pillans (2004). Over 27 hours, the sawfish moved 28.7 km at an average speed of 28.4 m.min-1 and was at all times within 200 m of the shoreline in very shallow water. Average water depth was 0.69 m. During the day, the sawfish was in slightly deeper water (0.84 m) compared to the night (0.48 m) indicating a diurnal shift in water depth. The preference for shallow water shown by the sawfish in this study and the fact that it moved parallel to the shoreline suggests they may occupy a relatively small area of available habitat that is concentrated in a narrow strip of water adjacent to the shoreline. These data are supported by studies on the small tooth sawfish (P. perotetti) in North America (Simpfendorfer 2000; Colin Simpfendorfer, Centre for Shark Research Mote Marine Laboratory, personal communication, 2003) where sawfish have been recorded along the shallow inshore regions of the coastline. However, P zijsron have also

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been recorded in water depth greater than 70 metres (CSIRO Marine Research, unpublished data) along the east coast of Queensland. Populations 16. What is the species’ total population size in terms of number of mature individuals? Are there other useful measures of population size and what are they? In the absence of figures, terms such as common, abundant, scarce can be of value.

Not known. See section 1.8 for comments on population trends.

17. Does the species occur in a number of smaller populations? How many? If available, for each population give the locality, numbers and trends in numbers and tenure of land (if available) (include extinct populations). Can these be considered to be subpopulations and why? Subpopulations are defined as geographically or otherwise distinct groups in the population between which there is little demographic or genetic exchange (typically one successful migrant individual or gamete per year or less).

Given the relatively uncommon occurrences of P. zijsron in catch data, it is difficult to say if subpopulations exist. It is a large species, and presumably is capable of long distance movements along the coast. Unless they are fished out locally across northern Australia, they should form a continuous population.

18. What is the population trend for the entire species?

g. What data is there to indicate past decline in size (if available, include data on rate of decline over past 10 years or 3 generations whichever is longer)?

h. What data is there to indicate future changes in size (if available, include data which will indicate the percentage of decline over 10 years or 3 generations whichever in longer (up to a maximum of 100 years in the future) where the time period is a continuous period that may include a component of the past)?

There are no species-specific data that show a decline in P. zijsron numbers. However, see section 1.8 and 1.11 for data on declines of sawfish worldwide and within Australia.

19. Does the species undergo extreme natural fluctuations in population numbers, extent of occurrence or area of occupancy? To what extent and why? Extreme fluctuations can be said to occur in a number of taxa when population size or distribution area varies widely, rapidly and frequently, typically with a variation greater than one order of magnitude (i.e. a tenfold increase or decrease).

Not known. Unlikely, as chondrichtyan life-history strategies provide more stable recruitment patterns than teleost fish.

20. What is the generation length and how it is calculated? Generation length is the average age of parents of the current cohort (i.e. newborn individuals in the population). Generation length therefore reflects the turnover rate of breeding individuals in a population. Generation length is greater than the age at first breeding and less than the age of the oldest breeding individual, except in taxa that breed only once. Where generation length varies under threat, the more natural, i.e. pre-disturbance, generation length should be used.

Pristis zijsron appears to reach 95% of its maximum length (508cm TL) at approximately 24 years of age and size at maturity (from direct observation) in 9 years (Peverell, James Cook University, unpublished MSc thesis). Based on these estimates of age, generation length is likely to be about 16 years. Survey effort 21. Has the species been reasonably well surveyed? Provide an overview of surveys to date and the likelihood of its current known distribution and/or population size being its actual distribution and/or population size

There have only been a few dedicated surveys for sawfish with P. zijsron being the most uncommon pristid in all surveys. In the Current FRDC funded “Northern Australian Sharks and Ray: The sustainability of target and bycatch species, Phase 2” only 21 P. zijsron have been recorded from Western Australia, the Northern Territory and Queensland. Thorburn et al. (2003) carried out a broad, field-based survey of freshwater elasmobranchs in northern Australia. In six months of field work, they surveyed 137 sites within 39 river/creek systems in Western Australia, the Northern

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Territory and Queensland covering some 30,000 km during the NHT funded project. Thorburn et al. (2003) caught only 3 P. zijsron (all around Weipa). Although fishing effort was directed more towards rivers and estuaries, it does indicate that the green sawfish is not abundant across the north. By comparison, this survey caught 16 P. clavata, 17 P. microdon and 2 Anoxypristis cuspidata.

Giles et al., unpublished report, summarise all available records of sawfish in Australia.

Based on these scientific surveys, and data from fisheries observers, it is unlikely that the known range of this species will increase with increased survey effort. Surveys in remote areas of the Northern Territory and Western Australia are likely to record this species in locations where they have not previously been documented. Nothing is known about population size. Threats 31. Identify past, current and future threats, to the species indicating whether they are actual or potential. For each threat, describe:

j. how and where it impacts on this species k. what its effect has been so far (indicate whether it is known or suspected; present supporting

information/research; does it only affect certain populations) l. what is its expected effect in the future (is there supporting research/information; is the threat only suspected;

does it only affect certain populations)

The toothed rostrum of sawfish makes them highly susceptible to capture in all fisheries that utilise nets. Gill net and trawl fisheries operate throughout the range of P. zijsron and pose the greatest threat to this species. Data from the Giles et al. (unpublished report) are summarised below and clearly show that P. zijsron are captured by all commercial and recreational fishing methods. Due to the danger of removing large specimens from nets and lines, many fishers kill sawfish before removing them from fishing gear. In addition, the high value of sawfish fins (white fin) which are worth up to $250 per kilogram results in animals that would normally be released being retained. Habitat alteration and destruction caused by coastal development is also likely to have a negative influence on this species.

In the future, the impact can be minimized across the less developed north by the introduction of Marine Planning Areas that represent bioregions, as envisaged by DEH/NOO. The present coastal and offshore gillnet fisheries (especially in the Gulf of Carpentaria) have wet season closures to protect barramundi spawning from October-January in the Northern Territory and November-January in Queensland. Some protection for pupping green sawfish may be gained by this management closure. Similar controls on other commercial finfish operations, eg bait net fishers in the Northern Territory and Queensland. would enhance this protection. Bait net fisheries are of special concern as catches are poorly monitored and often unreported. This is because animals captured in the net are used as crab bait and therefore fins from these animals can be marketed without associated trunks. These bait net fisheries operate in shallow near-shore habitat and are not under the same management regulations as barramundi fisheries (ie seasonal and or spatial closures which apply to barramundi fisheries do not apply to bait net fisheries). If there are no changes to gillnet (and longline) fishery management regulations, then there will be gradual depletion of sawfishes across the north with current fishing pressure.

Global threats to sawfishes and to freshwater elasmobranchs in general have been summarised by Compagno and Cook (1995). These authors note that the observations of Thorson (1976, 1982, 1987) were the first to raise conservation concerns over this group of fish. While the level of threats in Australia are much less than in most undeveloped countries, habitat degradation, pollution and overfishing are still impacting on sawfish populations. Truelove (2003) provided some information on the traditional utilisation of freshwater pristids, noting that they may represent a valuable, traditional source of food. Pristids have very high cultural and religious importance to some communities and there may be cultural restrictions on who can take them, limited to particular times and places. Some communities may use pristids as food for ceremonial purposes and McDavitt (1996) gives a brief account of some of the tribal mythologies and cultures relating to pristids among communities in Central America, West Africa and Papua New Guinea, noting that in some societies sawfish have powerful totemic meaning. Pristid rostra are used for

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ceremonial purposes by indigenous people (Environment Australia 1998) and there are anecdotal reports that indigenous people in the Weipa and Karumba area are buying sawfish rostra from commercial fishers. The rostra are then painted and the end product put onto the tourist market in Cairns (Truelove 2003). Giles et al. (CSIRO Marine Research, unpublished report) reviewed commercial and recreational catch records for sawfish, including P. zijsron, from a wide range of methods and available datasets in northern Australia. They noted that the information base on sawfish distribution and abundance could be greatly improved by accessing the large amount of knowledge and experience possessed by commercial fishers, particularly in the Northern Prawn Fishery and inshore net fisheries. They examined a number of research and commercial datasets over the last 30 years for sawfish records, which had not been fully explored previously for this purpose. Commonwealth and State commercial fisheries likely to capture sawfish were identified in a previous risk assessment of elasmobranch vulnerability in northern Australian waters (Stobutzki et al., 2003), based on fishing methods and spatial distribution of effort. These fisheries were treated as the primary possible sources for logbook and/or observer data, and included those from demersal and semi-pelagic trawl, demersal and surface set gillnet, and hook and line fisheries. Some pelagic trawl and longline fisheries not included in the previous study, on the basis of the demersal habit of sawfish, were found to include a small number of sawfish records and were also included. Historical commercial fisheries likely to have caught sawfish, and live-collection licences were also targeted as data sources. The coverage of northern commercial fisheries with possible sawfish take documents the main areas of bycatch, but was not exhaustive; some fisheries were not considered due to the difficulty of obtaining data and because of time constraints. Recreational catch of sawfish is very difficult to quantify, the emphasis necessarily focusing on available anecdotal evidence. Rostra mounted on the walls of fishers’ homes and in public establishments are testament to a long history of catch in northern Australia, extending into the fairly recent period of history before fishing licences and gear restrictions were introduced in Australia’s north. An attempt was made to gather any available data and/or rostra dimensions from fishing clubs where sawfish are known to occur, and data sourced from previous research on recreational fisheries. Records in museum collections are often originally from the recreational sector. Research catch data for sawfish were gathered from CSIRO for all voyages in northern Australian waters, and for all collaborative projects for which data were available. Visits were made to a number of museums to gather catch records and measure and photograph sawfish remains. Other research organisations were contacted for any available information. Availability of contextual effort data varied considerably, and catch rates were calculated on a dataset basis wherever possible. For the commercial fisheries, fishing effort data necessary for the calculation of catch rates was not generally available. For the majority of the research datasets, sawfish catch was consistently recorded, in which case fishing events (shots, hauls etc) where sawfish were not caught were also incorporated into the database to allow the calculation of dataset catch-rates. All non-catch records in the database are mapped alongside catch in the respective research dataset descriptions. The species identifications in this report are those originally recorded, and were only corrected where there are ambiguities and where the intention is clear (e.g. saw shark vs. sawfish in Northern Territory), or where later verification was possible. The majority of records in the database were obtained from State agencies; primary Northern Territory logbooks and Queensland’s beach meshing program. State observer data made a very small contribution to the overall number of State records, and is presently the only data source for sawfish bycatch in Western Australia and Queensland fisheries. After the State fisheries, the most data were collected from historical fisheries, the Northern Prawn Fishery and research surveys, followed by collections, a small number from the aquarium trade, and miscellaneous reports. The majority of catch data from these fisheries are not species-specific, and are contained in the main CSIRO Marine Research report by Giles et al. that is appended with these conservation assessment templates. The main data pertaining to P.zijsron are summarized below. In the Commonwealth Northern Prawn Fishery, 448 sawfish were recorded from 1998-2003 of which only 16 (3.6%) were recorded as P. zijsron. In the Northern Territory commercial fishery logbook data, 1858 sawfish were recorded

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between 1994-2003. No species-specific data are available from the logbooks, and there is only very limited observer coverage with only 2 P. zijsron recorded in the current FRDC funded project. One of these was from a barramundi fisher and the other from the Northern Territory Joint Authority Shark Fishery. As logbooks do not itemise sawfish in Queensland fisheries, only a small number of commercial records were available from their CFISH database (combined weight/boat day) and these records were not itemised by fishery. A small amount of scientific observer records were available for the Queensland Inshore Net Fishery which are presented in Peverell (2005). Sawfish bycatch from the Queensland Shark Control Program (QSCP) contributes a large dataset from about thirty years of beach meshing around major Queensland population centres during the summer months; although these data are not species-specific. The QSCP dataset shows a clear decline in sawfish catch from 1970 to 1990 (Appendix 2, figure 1), over which period effort was relatively constant (N. Gribble, Northern Fisheries Centre, personal communication). Detailed data were available for a number of sawfish captured under an aquarium trade license, and some anecdotal information was gathered from an ex-operator in the same region. There are also around 250 high detail records from QDPI observer studies in the N3 and N9 fisheries (Peverell, QDPI Northern Fisheries Centre, Cairns, personal communication). Some of these data were not made available for the purpose of this assessment. Logbook data are not available for Western Australia’s commercial fisheries as sawfish are not itemised. North Western Australian fisheries cover a large expanse of remote coastline which is likely to support the healthiest populations of sawfish in Australian waters. A small amount of scientific observer data are available for some fisheries with 14 records from the Kimberly gillnet and barramundi fishery. The Taiwanese Pelagic Gillnet Fishery (TPGF) operated surface set gillnets in northern Australian waters from 1974 until 1986. Fishing took place offshore from the North West Shelf to Cape York, with effort concentrated on the area north of the Wessel Islands from the AFZ limit to 12 nautical miles from the coast. Sawfish recorded as a catch component in the AFZ logbooks were confined to three short periods on respective vessels in 1982 and 1984. Thirty pristids were recorded from one vessel between the 3rd and 29th June 1982, four between 1st February and 14th March 1984 by another vessel and 31 between 16th April and 13th September 1984 by another vessel. Length frequency data on sawfish catch were collected by the AFZ Observers, covering 389 sets, around 2% of the total gillnet sets (Stevens and Davenport 1991), and about half of the specimens were recorded to species. One P. zijsron was recorded. The Taiwanese pair trawl fishery operated from 1971 to the early 1990s, from about 26ºS, 112ºE east to 136ºE and north to 8ºS. AFZ logbook data show that the majority of pristid records (94%) were part of what appears to be a continuous record of sawfish over a 3 month period when one vessel caught 306 individuals between 10th September and 16th November 1984. Interpreting these data as a continual record of sawfish catch operating at 3.4 shots per day, as used for previous NPF calculations (CSIRO Marine Research, unpublished data), more than one sawfish was captured per shot over this 96 day interval. Daily catch was highly variable, with sawfish appearing in 69.5% of shots (at 3.4 shots/day); two sawfish or more in 32% of shots, and one sawfish captured in 37% of shots over the period. Fishing was concentrated over the area north of the Wessel Islands and Cape Arnhem, and sawfish were caught in depths of 27-96 m. Only 12 pristids were recorded from limited coverage of both the Taiwanese longline and Soviet trawl fisheries in northern Australia. One and four P. zijsron was recorded from the Taiwanese longline fishery and Soviet trawl fishery, respectively. As there were 748 trawls where no pristids were noted, this strongly suggests they were not normally recorded. From CSIRO research datasets on the North West Shelf, one pristid was caught from 279 FV Courageous trawls between 1978-79, and 12 pristids from 1750 RV Soela trawls from 1979-89. However, many of these trawls, particularly by FV Courageous were in midwater and thus unlikely to catch pristids. Of the 12 specimens caught by RV Soela, 10 were identified as P. zijsron. The FV Rachel conducted pelagic gillnetting surveys in near shore environments off the north coast of Australia in 1984 and 1985. Of the 26 pristids caught, one was P. zijsron. Fish surveys run by CSIRO at Embley, Karumba, Groote Eyland and Albatross Bay in the Gulf of Carpentaria between 1986-1996 caught 33 pristids none of which were P. zijsron. A summary of the data by gear type shows that net fishing accounts for most of the catch records in the database (80.2%), followed by trawling (16.6%), line (9.2%) and recreational gears (0.3%) The overwhelming majority of data

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(79.7%) are recorded at the family level. Of pristids recorded at the species level, 6.8% were P. zijsron. Anoxypristis cuspidata were found primarily offshore, with Pristis spp dominating inshore catch. Small numbers of P .zijsron and P .microdon were recorded offshore, and some A .cuspidata were recorded in inshore habitats. Records available for sawfish catch in Australian waters have greatly increased in number and diversity of sources in recent years, due to increasing efforts to monitor this group. The earliest sawfish records acquired in the study are museum specimens, with a small number of records distributed fairly evenly from 1883 to 1960. Records compiled from Australian fisheries begin with the start of the QSCP beach meshing in 1963. Research datasets provide data from around 1980, with historical fisheries contributing a large number of records in the early 1980s. The least number of records are available for the early to mid 1990s, with a reduction in sawfish captures in the QSCP, before the recording of sawfish became routine in the Northern Territory fisheries and NPF, and elasmobranch observer programs began in most northern fisheries. With the bias of the dataset toward more recent records, evidence that pristids as a group have decreased in abundance in northern Australia must be derived from analysis of catch rates calculated with comparative spatial and temporal distribution of effort. This has not been attempted in this report. See also sections 1.8 and 1.9

32. If not included above, identify catastrophic threats, i.e. threats with a low predictability that are likely to severely affect the species - Identify the threat, explain its likely impact and indicate the likelihood of it occurring (e.g. a drought/cyclone in the area every 100 years)

Not relevant to this species given the scale of the impacts of commercial fishing (gillnets, trawling) and coastal development over the last 100 years.

33. Identify and explain any additional biological characteristics particular to the species that are threatening to its survival (e.g. low genetic diversity)? Identify and explain any models addressing survival of the specie.

The relatively low fecundity of the pristids limits their ability to recover from fishing mortality.

Their apparent preference for shallow inshore waters as pupping grounds, increase the likelihood of their interaction with inshore gillnets.

There have been no studies on genetic diversity of P. zijsron (or other sawfish species).

Threat abatement and recovery 34. Identify key management documentation available for the species, e.g. recovery plans, conservation plans, threat abatement plans.

Protection or status at present is: NT Parks & Wildlife Conservation – Vulnerable. NSW Fisheries Management Act 1994 – Endangered. (not recorded from NSW waters for at least 20 years)

International Level:

IUCN Red List of Threatened Species as Endangered; FAO International Plan of Action for Sharks.

National Level: P. zijsron is not listed in the Department of the Environment and Heritage Draft Recovery Plan (2003). Bycatch Action Plans and Strategic Assessments for Australian Fisheries. Australian National Action Plan for Sharks. Commonwealth EPBC Act only lists P. microdon as Vulnerable.

Within Jurisdictions:

Northern Territory: In response to the acknowledged decline in pristids in these waters, shark fishers have recently

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(December 2004) adopted a ‘no take’ policy for all live sawfish (David McKee, NTDBIRD, personal. communication). There are a few P. zijsron recorded in the Northern Territory Joint Authority Shark Fishery, however, the major overlap of effort (gillnets) probably occurs with the barramundi gillnet fishery. No data are available on this fishery to date. Given the vulnerability of pristids to gillnets, especially in shallow coastal environments, capture rates of P. zijsron in the barramundi fishery is likely to be high.

Queensland: Gillnet fishers have adopted a Code of Conduct for releasing live pristids from nets (Stirling Peverell, QDPIF, Northern Fisheries Centre, Cairns, personal. communication). This is not a Queensland government law or requirement at present.

Western Australia: The majority of sawfish captured by inshore gill net fishers operating along the Eighty Mile Beach, area are released alive according to Rory McAuley (Fisheries WA, personal. communication). It is uncertain whether this occurs when observers are not present.

See also section 1.4

35. Give an overview of how threats are being abated/could be abated and other recovery actions underway/proposed. Identify who is undertaking these activities and how successful the activities have been to date

Refer section 34;

Some abatement is provided by the following temporal (seasonal) and spatial management regulations. However, these temporal closures were put in place for management of the barramundi (Lates calcarifer) fishery and NOT for elasmobranchs.

Gillnet/Longlines: In response to information demonstrating that sawfish are at “high risk” from commercial gillnetting, the Northern Territory Joint Authority Shark Fishery has established a voluntarily ‘no take’ status for all sawfish, encouraging all commercial fishers to release them alive. Due to the difficulty in releasing large live sawfish, combined with the high value of their fins; it is uncertain whether this initiative will prove effective. The compliance of commercial operators is currently being assessed using log book data (David McKee, NTDBIRD, personal. communication).

Barramundi spawning closures in Queensland (1 Nov-1 Feb) and the Northern Territory (1 Oct- 1 Jan) may offer some protection to P. zijsron, but do not offer the same protection as for teleosts due to the low fecundity and slow growth rates of pristids. These closures may offer short term protection to large females moving inshore to drop their pups, but at present there is insufficient data on sawfish life history to substantiate this. More data on habitat requirements and long-term movement patterns of P. zijsron of all sizes are urgently required to determine adequate means of reducing incidental capture of this species in commercial fisheries.

In the Northern Territory, commercial barramundi gillnetting is prohibited from most major rivers where it has been replaced by recreational fishing (private anglers and charter operators). The spawning closures (October-January) apply to all fishers. The closure of most rivers to commercial gill netting may have some benefits for P. zijsron, however increased effort outside of rivers and estuaries will possible negate these benefits. Again, data on movement patterns and habitat utilisation are required in order to assess the effectiveness of these spatial closures. The sub adult P. zijsron tracked in Port Musgrave (Queensland) was captured outside of the estuary and outside of the temporal closure and was therefore not offered any protection by management regulations designed for other species.

Western Australia has some spatial management of rivers and estuaries; however these are unlikely to influence the likelihood of sawfish capture.

Trawling: The Northern Prawn Fishery (NPF) has a prohibition on the take of any elasmobranchs from prawn trawls. There is some evidence that Bycatch Reduction Devices (BRD) may reduce the capture of sawfishes, and for Anoxypristis cuspidata, a significant reduction of 73% has been reported. Survival of sawfish passing through a BRD is unknown but this appears to be a significant issue in the NPF. The NPF has two major seasonal closures from approximately November-April and a mid-year closure for six weeks over July/August. The shortened fishing season and reduction in number of vessels in the NPF is likely to result in an overall reduction in sawfish mortality. However, given historical effort and long generation time in sawfish, their populations will not yet have recovered from

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historical fishing levels and any additional mortality is a serious threat to their long term survival.

The Commonwealth of Australia developed a National Bycatch Policy in 1999 and a Commonwealth Bycatch Policy in 2000. The National Policy restricts its attention to non-target discard species and non-target organisms affected by fishing gear, and does not include byproduct species which include elasmobranchs.

The Commonwealth Policy commits to prepare Bycatch Action Plans for all major Commonwealth fisheries. Plans for the NPF and the Torres Strait Prawn Fishery were implemented in 1999.

Turtle exclusion devices (TEDs) and BRDs have been trialled in the NPF since 1993 and became compulsory in this fishery in 2000. Trials to improve their performance through modifications are continuing. Projects are currently under way to evaluate the effectiveness of these devices, in collaboration with the fishing industry. A project by the Bureau of Rural Sciences, CSIRO and AFMA is monitoring the catch of sea turtles in the Northern Prawn Fishery. Results from these projects show that the use of TEDs and BRDs has resulted in a substantial decline in the catches of large animals such as turtles, stingrays and sharks. Sawfish are less likely to be effectively excluded by BRDs, however, some limited preliminary information suggests a 50% reduction in pristids and a 79% reduction in A. cuspidata (D. Brewer, CSIRO Marine Research, personal communication).

The Commonwealth Government has provided funds from the Natural Heritage Trust to establish the SeaNet extension service. The project is focused on increasing the rate of adoption by the commercial fishing sector of new fishing gear and practices to aid bycatch reduction and to implement environmental best practice.

The States and the Northern Territory have also been addressing bycatch in different ways. Western Australia and the Northern Territory have adopted the National Policy. Action plans or management plans for fisheries are being prepared in three States and the Northern Territory on a priority basis. The use of BRDs in two estuarine prawn trawl fisheries in New South Wales has been made mandatory, to save large quantities of juvenile fish. In Queensland, New South Wales and Western Australia, the recording of bycatch is currently being considered for compulsory inclusion in management plans.

However, there has been little or no response to the assessment or management of the non-target retained species (byproduct) in relation to either the effects on the species or the effects on the ecosystems.

36. Which populations are in reserve systems? Which of these are actively managed for this species? Give details

As detailed in the Conservation Assessment for P. microdon, Marine Reserves and National Parks across the north, and on the east coast offer some protection from commercial and recreational fishing impacts, especially in the recently declared Great Barrier Reef Marine Park (GBRMP) . The major reserves offering protection to P. zijsron are: Kakadu and GBRMP, see http://www.deh.gov.au/parks/ for details and for links to other State/Territory managed parks, such as Northern Territory mangrove (coastal) parks shown at http://www.nt.gov.au/ipe/pwcnt/index.cfm?attributes.fuseaction=open_page&page_id=116

None of the northern reserves/parks are specifically managed for pristids.

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Section 2 – Recovery, Conservation, Protection Additional information on legal status 1. Does the species have legal protection under other legislation or political agreements, e.g. Convention on International Trade in Endangered Fauna and Flora (CITES),Convention on Migratory Species (CMS) Pristis zijsron is not listed on CITES or CMS.

Additional information on distribution 2. Give locations of: captive/propagated populations; populations recently re-introduced to the wild; and sites for proposed population re-introductions. Note if these sites have been identified in recovery plans

One company, Cairns Marine Aquarium Fish, exports live P. zijsron. Stirling Peverell (QDPIF, Northern Fisheries Centre, Cairns, personal communication) is working with this company to obtain estimates of sawfish growth rates in captivity.

No other captive/propagated populations exist in Australia.

Additional information on habitat 3. Describe the specie’s non-biological habitat (e.g. aspect, topography, substrate, climate) and biological habitat (e.g. forest type, associated species, sympatric species). If the species uses different habitats for different activities (e.g. breeding, feeding, roosting, dispersing, basking), then describe each habitat

See sections 1.10 – 1.15

Pristis zijsron are not euryhaline and are therefore not found in freshwater or high up rivers and estuaries like P. microdon. They do occur in lower reaches of estuaries and river mouths (eg sawfish tracked in Port Musgrave was in water of 24 parts per thousand (Peverell and Pillans, 2004)). Limited data suggests that juveniles occur in inshore areas while larger animals have been recorded both inshore and offshore (see section 1.15).

4. Does the species use refuge habitat, e.g. in times of fire, drought or flood? Describe this habitat

See section 2.3

5. Is the species part of, or does it rely on, a listed threatened ecological community? Is it associated with any other listed threatened species?

Pristis zijsron has been found in the same areas as P. microdon and Glyphis sp. A within Port Musgrave (Stirling Peverell, QDPI, Northern Fisheries Centre, Cairns, personal communication)). In the Gulf of Carpentaria, P. zijsron has been recorded in the same areas as P. microdon. It has been recorded in the Van Diemen Gulf area with P. microdon and Glyphis sp. A and Glyphis sp. C. Within Joseph Bonaparte Gulf, it has been recorded with Glyphis sp. C and P. microdon (see Figure 2.5.1).

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Species

300 0 300 600 Kilometres 'W Pristis microdon

Figure 2.5.1. All records of Glyphis sp. A, Glyphis sp. C, Pristis microdon and P. zijsron in Australia (CSIRO Marine Research database). Additional information on population 6. Provide details on ages of sexual maturity, life expectancy and natural mortality

As noted above in Section 1.20, size at first maturity has been calculated at around 9 years from Peverell’s (James Cook University, unpublished MSc thesis) growth curve based on 19 specimens. Maximum size and age was estimated at 5.08 m and 24 years. There are no estimates of natural mortality for this, or any other species of sawfish.

7. Identify important populations necessary for the species’ long-term survival and recovery? This may include: key breeding populations, those near the edge of the species’ range or those needed to maintain genetic diversity

Any remaining populations on the east coast can be considered “near the edge of the species range” and as such are extremely important to maintain genetic diversity along the east coast. Mortality in all remaining populations in northern Australia also needs to be reduced in order to maintain genetic diversity within this region. Information on long term movements, as well as data on population genetic structure, is required to determine the status of the northern ‘stock’.

Remnant populations along the east coast may be partially protected by the latest GBRMPA Green Zones declared in 2003. Additional closures to gill netting of suitable inshore coastal habitat will be required in order to prevent this species from disappearing from the east coast. Survey methods 8. Describe methods for detecting species including when to conduct surveys (e.g. season, time of day, weather conditions); length, intensity and pattern of search effort; and limitations and expert acceptance; recommended methods; survey-effort guide

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Pristis. zijsron (and all pristids), are vulnerable to most types of fishing gear including nets (particularly gillnets and demersal trawls) and hooks. As described in Section 1.31, they are easily captured in commercial trawl and gillnets, as well as longlines.

Sampling should include a range of habitats from the coastal marginal zone and lower reaches of sheltered estuaries and embayments. Although short (30 m, 2.5 m drop) monofilament gill net panels, of 10, 15 and 20 cm stretched mesh are often suitable in riverine habitats, longer nets with a deeper drop should be used in coastal environments and large estuaries. Net length should be as long as is practical (100 – 200 m) and should have a drop that ensures the net is in contact with the substrate at all times. Nets should be set over mud/sand or rubble bottom in suitable locations. Given the movement patterns of a P. zijsron tracked in Port Musgrave (Peverell and Pillans, 2004), nets should be set in shallow water close to the bank. Ideally nets should be set from the high water mark at right angles to the shoreline. Nets should be set in multiple habitats including areas close to mangroves, sandy and muddy beaches, tidal channels, mud flat drains and mouths of suitable rivers and creeks. Because of the relatively low abundance of P. zijsron, gill net set-times may need to be spread over several days at any site. This requires the nets to be closely monitored to minimise stress and prevent the death of captured specimens. Another factor will be the amount of bycatch present; at sites with high bycatch nets should be checked every hour. When nets are set overnight, only larger mesh sizes should be used to minimise by-catch.

Long lines can also be used to capture P. zijsron but are not as effective as gillnets. Long lines should consist of a mainline of 9 mm rope with ganglions of at least 200 kg monofilament and 4-6/0 tuna circle hooks. Tuna circle hooks should be used in preference to other hook designs as the chances of gut-hooking animalsis much (Cooke and Suski, 2004). 9. Give details of the distinctiveness and detectability of the species

Pristis zijsron is easily identified by the pattern of rostral teeth. These are spaced at increasing intervals from the rostrum tip, with the longest separation at the junction of the rostrum with the head.

Sawfish are generally very hard to observe in their natural habitat. During the track of the green sawfish in Port Musgrave (Peverell and Pillans, 2004), the animal was only observed very briefly on a few occasion when the rostrum was seen breaking the surface. This was despite the fact that the float attached to the tag was observed on several occasions, and that the sawfish was in water less than 1 m deep for much of the track.

Reproduction 10. For plants: When does the species flower and set fruit? What conditions are needed for this? What is the pollinating mechanism? If the species is capable of vegetative reproduction, a description of how this occurs, the conditions needed and when. Does the species require a disturbance regime (e.g. fire, cleared ground) in order to reproduce? For animals: provide overview of breeding system and of breeding success, including: when does it breed; what conditions are needed for breeding; are there any breeding behaviours that may make it vulnerable to a threatening process?

Peverell (2005) inferred that pupping occurs during, or just before, the wet season. Pupping frequency is unknown but is likely to be every two years given the similarity in size to Pristis perotteti which only reproduces biannually (Thorson, 1976).

Little is known about reproduction in P. zijsron. As in other pristids, the reproductive mode is aplacental viviparity with lecithotropic nutrition of the embryos (energy reserves come from the egg). Pristids have some of the largest ova sizes in the chondrichthyes. Litter size in other pristids is up to 20. Pupping may occur in estuarine and coastal areas. At birth, the rostrum is well developed but soft and flexible, and covered by a firm membranous sheath (Merrick and Shimida).

Feeding 11. Summarize the species’ food items or sources and timing/seasonality

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One P. zijsron captured in a prawn trawl targeting banana prawns (Penaeus merguiensis) in Joseph Bonaparte Gulf had a banana prawn and two 8 cm TL Leiognathus bindus in its stomach. These data, and observations of feeding behaviour, suggest that P. zijsron feed on schooling fish and prawns. There are no other data on the diet of P. zijsron.

12. Briefly describe the species’ feeding behaviours, including those that may make the species vulnerable to a threatening process

Peverell and Pillans (2004) observed a 3.5 m female P. zijsron slashing its rostrum from side to side in shallow water. Herrings (Nematalosa come) and anchovy (Thryssa hamiltonii) were observed jumping out of the water during these episodes, presumably to escape from the sawfish.

The presence of sawfish around concentration of banana prawns greatly increases the probability of capture as these schools are actively targeted by prawn trawlers and are fished continuously when located.

Importantly, P. zijsron are not an ambush predator but actively pursue schools of baitfish and prawns. Data from the individual tracked in Port Musgrave (Peverell and Pillans, 2004), showed that it moved continuously throughout the track and did not rest on the bottom. This behaviour makes P. zijsron even more vulnerable to capture in gillnets as animals are more likely to encounter fishing gear if they are moving around an area as apposed to being inactive for long periods.

Movements 13. Describe any relevant daily and seasonal pattern of movement for the species, including relevant arrival/departure dates if migratory

Peverell (2005) suggests there is a general inshore pupping movement of pristids during summer (wet season).

The 27 hour track of a 3.5 m female in Port Musgrave (Peverell and Pillans, 2004) showed the animal utilised a very narrow area immediately adjacent to the shoreline. The area utilised by the animal overlaps with those fished by bait nets and commercial barramundi nets.

14. Give details of the species’ home ranges/territories

The acoustic tracking study by Peverell and Pillans (2004) was a 27 hour study with no opportunity to make inferences about home ranges/territories. Peverell (James Cook University, unpublished MSc thesis) tagged numerous sawfish but these data are not yet available.

Other 15. Is there other information that relates to the survival of this species that you would like to address?

Section 3 – References, referees Reference list

Cavanagh Rachel, D. (ed.); Kyne, Peter, M. (ed.); Fowler, Sarah, L. (ed.); Musick, John A. (ed.); Bennett, Michael B. (ed). (2003). The Conservation Status of Australian Chondrichthyans: Report of the IUCN Shark Specialist Group Australia and Oceania Regional Red List Workshop. The University of Queensland, School of Biomedical Sciences, Brisbane, Australia. X+ 170pp.

Compagno, L.J.V. and Cook, S. F,. (1995). The exploitation and conservation of freshwater elasmobranchs: status of

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taxa and prospects for the future. Journal of Aquaculture and Aquatic Sciences, 7: 62-89.

Cooke SJ, Suski CD (2004). Are circle hooks an effective tool for conserving marine and freshwater recreational catch-and-release fisheries?, Aquat. Conserv. 14: 299 - 326.

Gribble, N, Whybird, O, Williams, L and Garrett, R (2004). Fishery assessment update 1989-2003: Queensland Gulf of Carpentaria coastal shark catch. Information Series QI, May 2004.

Giles, J, Pillans, R, Miller, M and Salini, J (2005). Sawfish catch data in northern Australia: a desktop study. Report produced for FRDC Project 2002/064 Northern Australian Sharks and Rays: the sustainability of target and bycatch fisheries, phase 2.

Last, PR. and Stevens, JD (1994). Sharks and Rays of Australia. CSIRO Australia.

Manjaji, BM (2002). New records of elasmobranch species from Sabah. pp 70-77. In: Fowler, S.L., Reed, T.M. and Dipper, FA. (eds). Elasmobranch Biodiversity, Conservation and Management: Proceedings of the International Seminar and Workshop, Sabah, Malaysia, July 1997. IUCN SSC Shark Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. xv + 258 pp. McDavitt, M (1996). The cultural and economic importance of sawfishes (family Pristidae). Shark News 8 Newsletter of the IUCN/SSC Shark Specialist Group

Peverell, SC (2005). Distribution of sawfishes (Pristidae) in the Queensland Gulf of Carpentaria, Australia, with notes on sawfish ecology. Environmental Biology of Fishes, (in press)

Peverell, SC (James Cook University, unpublished MSc thesis). Sawfish (Pristidae) of the Gulf of Carpentaria, Queenland, Australia, James Cooks Univeristy, Unpublished MSc thesis.

Peverell, SC and Pillans, RD (2004). Determining feasibility of acoustic tag attachment and documenting short-term movement in Pristis zijsron Bleeker, 1851. Report for the National Oceans Office, 18 pp. Peverell SC, Gribble NA (2003). Sawfish (F. Pristidae) in the Northern Planning Area – Description of key species groups for the National Oceans Office Pogonoski, JJ, Pollard, DA and Paxton, JR (2002). Conservation overview and action plan for Australian threatened and potentially threatened marine and estuarine fishes. Environment Australia, February 2002 ISBN 0 642 54786 6 Rose, C and McLoughlin K (2001). Review of Shark Finning in Australian Fisheries. Final report to the Fisheries Resources Research Fund. Bureau of Rural Sciences. 166 pp.

Simpfendorfer, CA (2000). Predicting population recovery rates for endangered western Atlantic sawfishes using demographic analysis. Env. Biol. Fish. 58 (4): 371-377. Stevens, JD, and Davenport, SR (1991). Analysis of catch data from the Taiwanese gill-net fishery off northern Australia, 1979-1986. CSIRO Marine Laboratories Report 213, 51 pp Stobutzki, I, Stevens, J, Miller, M, Salini, J, Jones, P, Deng, R, Fry, G, Taranto, T (2003) The Sustainability of Northern Australian Sharks and Rays: Final report to Environment Australia. Tanuichi, T (2002). Outline of field surveys for freshwater elasmobranchs conducted by a Japanese research team. P. 181-184. In: Fowler, S.L., Reed, T.M. and Dipper, FA. (eds). Elasmobranch Biodiversity, Conservation and Management: Proceedings of the International Seminar and Workshop, Sabah, Malaysia, July 1997. IUCN SSC Shark Specialist Group. IUCN, Gland, Switzerland and Cambridge, UK. xv + 258 pp.

Thorburn, DC, Peverell, S, Stevens, JD, Last, PR and Rowland, AJ (2003). Status of Freshwater and Estuarine Elasmobranchs in Northern Australia. Report to Natural Heritage Trust, Canberra, Australia.

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Thorson, TB (1976). Observations on the reproduction of the sawfish, Pristis perotteti, in Lake Nicaragua, with recommendations for its conservation. In: Investigations of the ichthyofauna of Nicaraguan lakes (Ed. TB Thorson). University of Nebraska-Lincoln. p 641-650. Thorson, TB (1982a). Life history implications of a tagging study of largetooth sawfish, Pristis perotetti, in the Lake Nicaragua-Rio San Juan system. Environmental. Biology of Fishes. 7: 207 -228 Thorson, TB (1982b). The impacts of commercial exploitation on sawfish and shark populations in Lake Nicaragua. Fisheries 7: 2 – 10 Dated: Has this document been refereed? If so, indicate who:

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