Assessment of longline f ishing in the

Macquarie Island Toothfish Fishery

November 2010

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CONTENTS 1. Introduction....................................................................................................3

2. Background and design of the trial ................................................................3

2.1. Location ............................................................................................................ 3

2.2. Brief history of fishing at Macquarie Island............................................ 5

2.3. Bycatch ............................................................................................................. 5

2.4. Strategic Assessment requirements......................................................... 5

2.5. Seabirds............................................................................................................ 6

2.6. Scientific Permit conditions ........................................................................ 7

3. Trial of longline fishing in the MITF ................................................................8

3.1. Fishing program ............................................................................................. 8

3.2. Wildlife observations .................................................................................... 8

3.3. Patagonian toothfish ..................................................................................... 9

3.4. Bycatch ........................................................................................................... 11

3.5. Stock assessment........................................................................................ 11

3.6. Gear loss ........................................................................................................ 13

3.7. Benthic impacts ............................................................................................ 13

4. Summary .....................................................................................................14

5. Recommendation.........................................................................................14

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1. Introduction

A demersal longline trial was undertaken over four seasons from 2007 to 2010 by Petuna Sealord Pty Ltd in the Macquarie Island Toothfish Fishery (MITF). The key aims of the trial were to determine whether Patagonian toothfish (Dissostichus eleginoides) could be targeted by the longline fishing method in the Macquarie Ridge sector of the fishery, and whether the adopted mitigation strategies were effective at preventing the incidental capture of seabirds.

The trial, which comprised one trip and setting an average of around 290,000 hooks in each season, showed that toothfish can be harvested by the longline fishing method and the adoption of a range of best practice mitigation strategies can effectively avoid seabird interactions. No seabird interactions resulting in a bird being caught or injured were observed during the trial.

The trial has now concluded. The report has been prepared by the Australian Fisheries Management Authority (AFMA) for consideration as part of the process to determine whether longlining becomes an approved fishing method in the MITF.

2. Background and design of the trial

AFMA manages the toothfish (Dissostichus spp.) fisheries in the MITF, the Heard Island and McDonald Islands (HIMI) Fishery and Australian operations in New and Exploratory fishing ventures approved by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR). Patagonian toothfish is the target species in the MITF.

At its meeting on 10 and 11 July 2007 the AFMA Board 1 agreed to the commencement of a trial

of longline fishing in the MITF, with annual reviews, subject to conditions and specific limits for seabirds. Petuna Sealord Pty Ltd undertook the trial with the longline vessels Avro Chieftain (in 2007 and 2008) and Janas (in 2009 and 2010). The company fully complied with all the trial conditions prescribed by AFMA.

Annual reviews were undertaken with details of the previous years operations provided to the AFMA Commission. Following this consideration approval was given to continue the trial.

A similar process was used before longline fishing became an approved fishing method in the HIMI Fishery.

2.1. Location

Macquarie Island falls under Tasmanian jurisdiction and is located outside the Antarctic convergence approximately 1500 kilometres south east of Hobart.

The waters surrounding Macquarie Island out to 3 nautical miles are Tasmanian State waters and the Tasmanian Department of Primary Industries, Water and Environment controls fishing in these waters. State waters were closed to fishing and classified as a Nature Reserve under Tasmanian law in July 2000. Waters from the 3 nautical mile boundary out to the 200 nautical mile outer boundary of the Australian fishing zone are under Commonwealth jurisdiction and fishing in these waters is managed by AFMA under the Fisheries Management Act 1991.

Figure 1 shows an indicative map of the location of Macquarie Island. Australia shares a maritime delimitation boundary with New Zealand whose Exclusive Economic Zone (EEZ) abuts the Australian fishing zone north-east of Macquarie Island.

1 Prior to July 2009 AFMA was a statutory authority with a Board of Directors. AFMA is now a Commission and the

term ’AFMA Commission’ is also used in the document.

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Figure 1: Indicative map showing the location of Macquarie Island

In the Macquarie Island Toothfish Fishery Management Plan 2006 (the MITF Plan) the area of the fishery is divided into two sectors: the Aurora Trough and the Macquarie Ridge.

The maps at figure 2 show in greater detail the location of the Aurora Trough sector (the major trawl fishing ground), the Macquarie Ridge sector, the Macquarie Island Marine Park and the World Heritage area. The Aurora Trough and Macquarie Ridge sectors were both fished during the longline trial.

Figure 2: Indicative maps showing the location of the Aurora Trough and Macquarie Ridge sectors and the Macquarie Island Marine Park and World Heritage area

Red – Aurora Trough, Yellow – Macquarie Ridge, Green – Macquarie Island Marine Park

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2.2. Brief history of fishing at Macquarie Island

Currently trawl fishing is the only authorised fishing method in the MITF. Trawl fishing commenced in the fishery in 1994.

Most of the EEZ around Macquarie Island comprises deep oceanic waters (>2000 metres deep) and the fishable area is confined to a ridge, about 170 nautical miles long by up to 14 nautical miles wide, together with a few small outlying banks. Much of these waters are unsuitable for trawling given the rough terrain. The main trawl fishing ground is the Aurora Trough which is an area of approximately 130 square kilometres located to the west of the Island (see maps at figure 2).

Separate total allowable catches (TACs) for Patagonian toothfish are set for the Aurora Trough and Macquarie Ridge sectors. They have been relatively small (290 tonnes in 2010/11) compared to those set for the HIMI Fishery (2550 tonnes in 2009/10). On a number of occasions a research TAC (of up to 60 tonnes) has been set for the Aurora Trough when the stock assessments have shown that less than 66.5% of the pre-fishing trawl available biomass was available to fishing.

The MITF Plan makes provision for the issue of Scientific Permit to allow for other fishing methods. The longline trial was conducted using Scientific Permits issued by AFMA for each year of the trial.

When commercial trawl fishing takes place it is generally conducted over a 4 to 6 week period as part of a single trip to the fishery. Similarly, the TAC set for the longline trial has taken up to 5 weeks to catch. No other fishing takes place outside these periods.

The table at Attachment A summarises the historic TACs set and catches taken in the fishery.

2.3. Bycatch

A precautionary bycatch limit of 200 tonnes combined per season applies for all finfish species (excluding Patagonian toothfish), crabs and sharks, with a 50 tonnes limit on any one species. Data is collected by observers on all species.

2.4. Strategic Assessment requirements

While longlining is almost universally employed in toothfish fisheries managed through CCAMLR, longlining within the MITF has not been permitted due to the potential of the fishing method to incidentally interact with seabirds.

The ‘Assessment Report – Macquarie Island Toothfish Fishery – November 2005’ outlined approval process for introducing longlining into the MITF, and includes the development of seabird bycatch mitigation strategies and the requirement for approval of the fishing method by the Minister for the Environment and Heritage (now the Minister for Sustainability, Environment, Water, Population and Communities).

The recommendation from the Department of Sustainability, Environment, Water, Population and Communities in relation to longlining and the strategic assessment is:

‘AFMA to monitor interactions with protected species, in particular seabirds, to ensure that risk of interactions do not increase due to changes in the levels of effort, fishing capacity or methods such as additional boats entering the fishery or the use of longlines. In the event that risk levels increase or cumulative effects are detected then AFMA should develop and implement further mitigation measures as a matter of highest priority. In the event of an interaction occurring with a Critically Endangered species then additional mitigation measures should be immediately adopted to prevent further interactions.’

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2.5. Seabirds

The following mitigation strategies to avoid potential seabird catches and seabird limits were applied during the longline trial in the MITF.

Bycatch mitigation measures

The bycatch mitigation measures approved by the AFMA Board for the longline trial were:

• one longline vessel operated during the trial – one vessel operated by Petuna Sealord Pty Ltd was permitted to longline at any one time;

• no offal discharge - the prohibition on the dumping of offal, which is applied to all Australian vessels operating in sub-Antarctic and Antarctic waters, was adopted in the MITF;

• limited season – longline operations were restricted to the period between 1 May and 31 August each season;

• night setting - setting could only occur during the hours of darkness between the times of nautical twilight;

• integrated weight line – integrated weight line (IWL) was used which was capable of achieving the CCAMLR standard for IWL of a sink rate of 0.2 metres per second. Sink rate tests for the IWL gear were required before the vessel entered the fishery;

• observer coverage - 2 full time observers were deployed on each trip and duties included the monitoring of wildlife abundance and any interactions;

• paired streamer lines - two streamer lines (with specifications to type and dimensions) were used to scare birds away from gear;

• ‘brickle curtain’ – this device (designed and developed by Petuna Sealord Pty Ltd and subsequently adopted by CCAMLR), was used on the vessel Janas to discourage birds from accessing baits during the haul of longlines. Some minor improvements to the brickle curtain design were made during the course of the trial to improve its deterrence affect on giant petrels. The Avro Chieftain had a moonpool which negated the need to use a brickle curtain as the longline was hauled through the keel of the vessel;

• prohibition on the use of plastic packaging bands - to prevent ingestion of or entanglement in the debris by seabirds or marine mammals; and

• minimisation of lighting – to reduce the risk of seabirds colliding with the boat.

Limits on seabirds

The AFMA Board recognised the particular circumstances surrounding the seabird populations of Macquarie Island and agreed that trigger catch limits on seabirds should apply during the trial, subject to an annual review. The limits were developed in consultation with Statutory Fishing Right holders in the MITF. Table 1 below listed the species in each category and the action that were to be taken if a seabird was killed. These limits were in addition to the bycatch rate of 0.01 birds per 1000 hooks set for Antarctic fisheries by the ‘Threat Abatement Plan for the incidental catch (or bycatch) of seabirds during oceanic longline fishing operations’ (TAP).

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During the trial no more than three seabirds in total could be taken in a season. This was a maximum number and the actual limit may have been less depending on which category the seabird species falls into (see Table 1). For example, if one seabird from category one was killed then fishing would have had to cease for the remainder of the season. If one seabird from category 2 and one from category three were taken then operations could have continued, but any additional seabird death would have resulted in the cessation of fishing for the season.

Category Seabird species Action

1 Wandering albatross

Black-browed albatross

Grey-headed albatross

Grey petrel

Soft-plumaged petrel

If one seabird from this category was killed as a result of an interaction with fishing gear then longline fishing would have ceased for the remainder of the season

2 Southern giant petrel

Northern giant petrel

Light-mantled sooty albatross

Blue petrel

If two seabirds from this category were killed as a result of interactions with fishing gear then longline fishing would have ceased for the remainder of the season

3 All other seabirds If three seabirds in total from categories 2-3 were killed as a result of interactions with fishing gear then longline fishing would have ceased for the remainder of the season

Table 1: Seabird categories and actions to be taken if an interaction occurs

2.6. Scientific Permit conditions

In addition to the seabird bycatch mitigation measures outlined in section 2.5, several other measures were included in the Scientific Permits which enabled the trial to proceed. The Scientific Permit specified the conditions agreed to by the AFMA Commission, and included supplementary instructions from scientists from the Australian Antarctic Division (AAD) on the biological data to be collected. These included:

• spreading effort as much as practicable to enable as much information on species distribution as possible;

• tagging toothfish at a rate of 3 tags per tonne to continue the extensive tagging work that has been undertaken in the fishery in trawl operation since 1995;

• count of the birds around the vessel at the same time once each day provided the vessel is not hauling or setting to provide estimates of species presence and abundance;

• conduct line weighting trials to ensure line sinks at least as rapidly as the CCAMLR standard;

• record time, position etc. of sets & hauls in the FishLog database;

• observe at least 60% of hooks set for seabird interactions;

• observe at least 50% of hooks for bird and fish bycatch in all hauls;

• record catch composition of each haul and take biological observations on common bycatch species;

• undertake biological sampling of Dissostichus spp. in commercial hauls;

• collect specimens of bycatch species, as required; and

• undertake conversion factor experiments to determine the whole weight from processed weight.

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In 2007, 2009 and 2010 additional Scientific Permits were issued to allow longline operations in the Aurora Trough sector. This work provided additional data on selectivity and temporal information on the Aurora Trough stock, which historically has been fished in late summer by the trawl fishing method.

3. Trial of longline fishing in the MITF

3.1. Fishing program

Petuna Sealord Pty Ltd conducted the longline trial over four seasons using the vessels Avro Chieftain in 2007 and 2008 and Janas in 2009 and 2010. The company fully complied with all measures prescribed by AFMA.

A single trip was undertaken each season to catch the available Patagonian toothfish TACs. Each season longline operations were completed within a period of up to five weeks.

Table 2 gives a broad summary of the annual longline operations.

Sector

Vessel Period Macquarie Ridge catch

(tonnes)

Aurora Trough catch

(tonnes)

Avro Chieftain 1 to 18 August 2007 83.5 5.0

Avro Chieftain 1 to 29 July 2008 147.9 did not fish in this sector

Janas 15 July to 20 August 2009 146.1 66.2

Janas 17 May to 14 June 2010 138.9 124.9

TOTAL 516.4 196.1

Table 2: Annual longline catch summary by sector and season

All voyages took place in winter to minimise the risk of seabird bycatch with line setting only occurring at night.

3.2. Wildlife observations

The seabird bycatch mitigation strategies (outlined in section 2.5) were fully complied with during all voyages. The range of mitigation strategies are best practice and incorporate all known measures which effectively limit the potential for interactions with seabirds. No seabird interactions resulting in the death or injury of a bird were observed on any of the four voyages.

Should longlining become an approved fishing method in the MITF, AFMA will continue to apply a range of mitigation strategies to avoid potential seabird bycatch. The mitigation strategies are provided in Attachment B.

The Avro Chieftain had a moon-pool which had the line being hauled through an opening in the keel of the vessel where the line is not exposed to seabirds. This negated the need to use a ‘brickle curtain’ (a device designed by Petuna Sealord Pty Ltd consisting of a barrier of floats which is set around the line when it is being hauled).

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Two observers were deployed on the vessel. The instructions to the observers in relation to wildlife observations were:

• observe at least 50% of hooks set during night time for seabird interactions;

• observe at least 50% of hooks for bird and fish bycatch in all hauls; and

• count birds around the vessel at the same time once each day provided the vessel is not hauling or setting.

Two tori lines were used on all the line sets conducted, and lighting was kept to a minimum for safe operations at all times during the voyages.

One marine mammal interaction was observed in 2008. A New Zealand fur seal swam into the moon-pool on the Avro Chieftain and was hooked through the right fore flipper and cut free. The animal continued swimming around the moon-pool for around 10 minutes before leaving with a hook embedded in the flipper. It came back momentarily before continuing to take fish from the line below the vessel’s moon-pool.

3.3. Patagonian toothfish

Following each voyage Mr Dick Williams (formerly a fish biologist employed by AAD) was commissioned by Petuna Sealord Pty Ltd to prepare a report on the fisheries research aspects undertaken. These reports were prepared using AFMA observer data. Much of the following information is summarised from Mr Williams’ reports.

The data collected (outlined in section 2.6) during the longline trial complemented the existing data set which has been collected in the fishery since trawl operations began in 1994. The data will be incorporated into the Stock Synthesis 3 integrated assessment model which has been developed by CSIRO for the fishery.

Methods

In the first three years of the trial Petuna Sealord Pty Ltd was requested to spread effort as much as practicable within areas of the Macquarie Ridge. This was achieved. At each site fished, between five and eight magazines each containing 875 hooks (for a total of 4750 to 7000 hooks), were set. An integrated weight line (IWL) containing 50 grams of weight per metre of line was used with 14/0 hooks spaced at 1.4 metre intervals. Squid was used as bait.

During the fourth year of the trial the operations were commercially oriented and the vessel fished in numerous locations to maximise catch.

Two observers were on board and counted and weighed the entire catch of each species and made biological observations and collections on Patagonian toothfish and the principal bycatch species (Macrourus carinatus, Antimora rostrata and a morid species). Biological observations comprised measurement of standard and total length and weight; determination of sex, gonad maturity stage and collection of otoliths.

Results were entered directly into the AAD’s fish database Fishlog on the vessel and quality controlled on return to Hobart. This report uses the data compiled by Mr Williams and AFMA from Fishlog and from information supplied in the observers’ report to AFMA.

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Catch

All toothfish caught were Patagonian toothfish. No Antarctic toothfish (Dissostichus mawsoni) were caught. The catch taken in each sector is summarised in table 2 above.

The average weight per toothfish taken in longline operations was 6.9 kilograms in the Aurora Trough and 9.5 kilograms in the Macquarie Ridge, which contrasts to averages of 3.8 and 1.7 kilograms from the trawl fishery in each sector respectively.

Toothfish tagged and recaptured

A total of 2433 toothfish were tagged and were spread over all locations fished, except for the far north. The observers were asked to tag three fish per tonne of toothfish caught in each locality, which is a higher rate than that undertaken in the HIMI Fishery (1 fish per tonne). This strategy was adopted to maximise the data coming from the trial and address stock structure issues. 151 tagged fish were recaptured. All tagged fish were released close to their point of capture.

Of the 151 recaptures, 120 (79%) had moved less than 10 nautical miles during up to 12.8 years at liberty. 108 of these fish (72% of the total recaptures) stayed within the same ground in which they were released, suggesting fidelity to site of release is strong. The remaining 12 short distance movers were recaptured in an adjacent ground. This pattern is similar to toothfish recaptures in the HIMI Fishery, where the majority of recaptures occur near the point of release.

Fifty-nine of the 120 recaptures were from the Aurora Trough. 22 of these fish that stayed within the Aurora Trough were at liberty for more than four years. The large number of fish that have stayed within Aurora Trough with a generally long time at liberty is a consequence of the very large number of fish tagged within the Aurora Trough since 1997 during the trawl fishery.

Thirty-one of the recaptures had moved more than 10 nautical miles. 13 of these fish originated in Aurora Trough, all but one released during trawl fishing, and all moved southwards. 3 fish had moved virtually the entire length of the main ridge a distance of 75 – 96 nautical miles.

(photo; AFMA Observer Section)

One fish was recaptured with a foreign tag of the type used by New Zealand and CCAMLR in Antarctic waters. Data on the release of this fish has not been obtained as yet but circumstantial evidence suggests that it may have been tagged in the New Zealand EEZ on the northern extension of the ridge in early 2009. This would mean the fish travelled about 200 nautical miles in four months. This is particularly noteworthy as it is the first recorded capture of a fish originating outside the EEZ around Macquarie Island.

Toothfish length frequency

Catch-weighted length frequencies were obtained from the spread of fishing grounds. A total of 9517 fish were measured from a total estimated catch of 79844 fish.

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The longline fishery is characterised by taking a mixture of adolescent and mature fish. The grounds in valleys on top of the ridge and sheltered from the open ocean (including the Aurora Trough) are characterised by a preponderance of fish <1000 mm in length.

These data reinforce the notion derived from the trawl fishery that the Aurora Trough is a haven for smaller fish. The Aurora Trough cannot be considered a nursery ground because around 255 of the fish are <800 mm and around 5% are <650 mm.

Sex and gonad stage

Among the 9517 fish measured, 7077 (2746 males, 4331 females) were examined for sex and gonad stage. Males comprised 38.8% of the sample and females 61.2%. Stages 1 and 2 (immature and maturing virgin) are considered as ‘immature’ whereas stages 3 to 6 (developing, ripe, ripe running, spent and recovering) are considered ‘mature’.

Of the fish examined 9.8% of the males were considered mature and 6.0% of the females were considered mature. The locations where mature fish were caught were similar for both males and females, and tended to be on the exposed flanks of the ridge. There were variations in the percentages of mature fish each season which reflected the areas fished and the timing of fishing each season.

3.4. Bycatch

The trial showed that longlining is a method which effectively targets toothfish. Very little bycatch was taken in longline operations, and catches were well within the limits determined for the fishery. The total fish bycatch for the 4 years of the trial was 42.8 tonnes.

The principal bycatch species recorded were Macrourus carinatus (macrourid), Antimora rostrata (blue antimora), morid cods and Lithoides murrayi (crab).

In contrast to toothfish fisheries elsewhere (HIMI, Kerguelen, Ross Sea, South Georgia) where skates are the major bycatch species, there was no skates caught on the Macquarie Ridge proper. However, a number of skates were recorded for the first time in the far northern area, where there is a connection with the New Zealand continental shelf.

Table 4 shows the whole weight of toothfish and the principal bycatch species in the Macquarie Ridge. The average whole weight per fish of Antimora rostrata was 1.62 kilograms which equates to a total catch of 13,101 kilograms during the trial. For Macrourus carinatus the average whole weight per fish was 1.89 kilograms which equates to a total catch of 23,734 kilograms during the trial. The bycatch of both species is well below the limit of 50 tonnes set by AFMA for any bycatch species and within the 200 tonnes of total bycatch for the fishery.

Very little bycatch was taken in the Aurora Trough sector. Table 5 shows the whole weight of toothfish and the principal bycatch species.

3.5. Stock assessment

An integrated assessment model has been developed by CSIRO to apply to the MITF. The model replaced the tag based assessment model versions which had been used in the fishery since assessments first began, and integrates the emerging spatial and temporal changes that are occurring in the fishery. In 2010/11 it was applied in setting the TAC in the Aurora Trough for the first time.

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Table 4: Weight (kilograms) of Patagonian toothfish (TOP) and principal bycatch species as a percentage of TOP in the Macquarie Ridge sector

Patagonian toothfish (TOP)

Antimora rostrata Macrourus spp. Morids Lithodes murrayi

Year Weight (kgs) Weight (kgs) % of TOP Weight (kgs) % of TOP Weight (kgs) % of TOP Weight (kgs) % of TOP

2007 83,500 2,609 3.12 3,800 4.55 295 0.35 9 0.01

2008 147,900 6,451 4.36 8,188 5.54 476 0.32 12 <0.01

2009 146,100 2,434 1.67 6,995 4.79 134 0.09 23 0.01

2010 138,900 1,607 1.16 4,751 3.42 52 0.04 34 0.02

TOTAL 516,400 13,101 2.54 23,734 4.60 957 0.19 78 0.01

Table 5: Weight (kilograms) of Patagonian toothfish (TOP) and principal bycatch species as a percentage of TOP in the Aurora Trough sector. Note: no longlining occurred in the Aurora Trough in 2008.

Patagonian toothfish (TOP)

Antimora rostrata Macrourus spp. Morids Lithodes murrayi

Ground Weight (kgs) Weight (kgs) % of TOP Weight (kgs) % of TOP Weight (kgs) % of TOP Weight (kgs) % of TOP

2007 5,000 0 - 11 0.22 0 - 0 -

2009 66,200 4 <0.01 249 0.38 0 - 4 <0.01

2010 124,900 30 0.02 569 0.46 17 0.01 41 0.03

TOTAL 196,100 34 0.02 829 0.42 17 <0.01 45 0.02

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The trial has provided valuable information which should help resolve issues around the stock structure on Macquarie Ridge. In this area an extremely large biomass of fish was observed in one year but it has not been available to the trawl fishery since that time. The high tagging rates undertaken during the trial will provide a more complete picture of stock structure and movement for the fishery.

However at this stage there is insufficient data at this stage to apply the model to the Macquarie Ridge sector which has been subject to a longline fishing trial. Continued fishing in the future would provide the additional information necessary to apply to the model.

SARAG is of the view that the toothfish in the Aurora Trough and Macquarie Ridge sectors are likely to form a single stock. The information from the longline trial, results from the Management Strategy Evaluation and biological work being conducted by CSIRO are important in addressing the single stock issue. CSIRO and SARAG will assess the situation prior to the start of the 2011/12 season, which starts on 15 April 2011.

3.6. Gear loss

Table 6 summarises the gear that was lost during the trial. A significant amount of gear was lost in 2008 and 2009, which in part was a result of the exploratory nature of fishing operations.

In response to this gear loss, Petuna Sealord Pty Ltd in 2010 replaced the 11.5 mm integrated weight line (IWL) with 12 mm IWL which increased the breaking strain by 20%. The operations were more commercially focused and toothfish was targeted in specific areas, including those areas with less rough ground. This strategy and the use of stronger integrated weight line and line tensioners resulted in significantly less gear being lost. Accordingly, 2010 is likely to be more indicative of normal commercial longline fishing operations.

Gear lost

Year Integrated weight line (metres)

Downline (metres)

Hooks Hooks lost vs set (%)

2007 8,085 3,360 6,775 4.1

2008 35,157 7,750 25,112 7.0

2009 44,940 6,300 32,325 7.9

2010 8,582 2,367 6,130 2.3

TOTAL 96,764 19,777 70,342 5.9

Table 6: Summary of gear lost during the longline trial

3.7. Benthic impacts

The impacts of demersal longlining on benthic habitats are not well understood. The Fisheries Research and Development Corporation approved a project (commenced 1 July 2006) to investigate ‘Demersal fishing interactions with marine benthos in the Australian EEZ of the Southern Ocean: an assessment of the vulnerability of benthic habitats to damage by demersal gears’. The development of underwater camera technology which can be attached to the fishing gear (trawl, longline and pot) is a key aim of the project along with assessment of benthic interactions of the differing gear types.

The final report is due in July 2011, and the outputs and implications will be discussed by SARAG and SouthMAC at that time. The results from this work can be effectively adopted in the MITF as well as in the HIMI fishery and the CCAMLR region more generally.

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4. Summary

Demersal longline fishing is the main fishing method used to target toothfish in Antarctic and sub-Antarctic fisheries. Since it became an approved fishing method in the HIMI Fishery it has become the major method for targeting toothfish.

The trial showed that:

• Petuna Sealord Pty Ltd complied with all conditions prescribed by AFMA;

• the mitigation strategies adopted to avoid interactions with seabirds proved to be successful with no seabird deaths or injuries being reported on any of the four voyages;

• there was one minor interaction with a marine mammal;

• Patagonian toothfish can be effectively targeted by longlining in both the Aurora Trough and the Macquarie Ridge sectors of the fishery;

• longlining provides access to toothfish in deeper waters with uneven topography that are unavailable to trawlers;

• the longline method targets larger (and older) toothfish;

• low levels of bycatch were reported and the catch of bycatch species was well below the limits specified for the fishery; and

• gear loss has been significantly reduced during the course of the trial as a result of changing fishing strategies and gear modifications.

5. Recommendation

The AFMA Commission met on 25 and 26 October 2010 to discuss the longline trial and recommended that demersal longline fishing becomes an approved fishing method in the Macquarie Island Toothfish Fishery, subject to the following measures:

• that the range of best practice mitigation strategies adopted during the trial to limit the potential for interactions with seabirds be continued for future longline operations. The mitigation strategies are outlined in Attachment B;

• that the group of seabirds comprising wandering albatross, black-browed albatross, grey headed albatross, grey petrel and soft-plumaged petrel have a trigger limit of one, to apply on a per vessel basis. This would mean that if one of the species were killed as a result of an interaction with the fishing gear, the vessel would be required to immediately cease fishing in the MITF for the remainder of the season; and

• that any interactions with other seabird species should be dealt with in the measures outlined in ‘Threat Abatement Plan for the incidental catch (or bycatch) of seabirds during oceanic longline fishing operations’, where a seasonal rate of 0.01 birds per 1000 hooks is specified. The rate would be applied retrospectively over a season to the fishery as a whole, so the capture of a bird(s) would not require an operator to cease fishing for the season. The review procedures outlined in the TAP would be applied.

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Attachment A

Summary by season of total allowable catches (TACs) set and catch taken in the Macquarie Island Toothfish Fishery

Total allowable catch and catch by sector

Aurora Trough Macquarie Ridge Season

TAC (tonnes) catch (tonnes) TAC (tonnes)** catch (tonnes)

1994 – 31/08/96 not set 1351 not set 0

01/09/96 – 31/08/97 750 489 1000 586.0

01/09/97 – 31/12/98 200 200 1500 397.0

01/01/99 – 31/12/99 40 (research)* 36 600 (1000) 26.0

01/01/2000 – 31/12/2000 40 (research)* 11 510 (1000) 7.0

01/01/01 – 31/12/01 40 (research)* 23 420 (1000) 0.1

01/01/02 – 31/12/02 40 (research)* 36 242 (782) 2.5

01/01/03 – 30/06/03 40 (research)* 0 205 (665) 0.6

01/07/03 – 30/06/04 354 352 174 (441) 0.7

01/07/04 – 30/06/05 60 (research)* 57 148 (376) 0.6

01/07/05 – 30/06/06 255 241 125 (319) 8.5

01/07/06 – 30/06/07 241 238 100 (264) 0.1

01/07/07 – 30/06/08 390 223 86*** 84.0

01/07/08 – 30/06/09 312 307 150*** 149.7

01/07/09 – 14/04/10 60 (research) 66 150*** 146.1

15/04/10 – 14/04/11 140 125 150*** 138.9

* a research TAC for Aurora Trough was set to enable the tag based stock assessments to be undertaken. The research TACs were set at a maximum of 40 tonnes per annum from 01/01/1999 to 30/06/2003 and at a maximum of 60 tonnes in the periods from 01/07/2004 to 30/06/2005 and 01/07/2009 to 14/04/2010. Commercial TACs were not set during these periods.

** for the Macquarie Ridge sector the tonnage (shown in brackets) would have been triggered if trawl catch rates reached a threshold of 10 tonnes per km

2 over 3 consecutive fishing days. The TAC has not been

triggered since operations began.

*** the TACs shown are those set for the longline trial.

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Attachment B

Seabird mitigation measures recommended to be adopted for demersal longline operations in the Macquarie Island Toothfish Fishery

The following mitigation strategies to avoid potential seabird catches are recommended to be adopted in the Macquarie Island Toothfish Fishery for demersal longline operations.

a) no offal discharge - a prohibition on the dumping of offal, which applies to all Australian vessels operating in sub-Antarctic and Antarctic waters, including in the Macquarie Island Toothfish Fishery;

b) limited longline season - a season of 1 May to 31 August;

c) night setting - setting can only occur during the hours of darkness between the times of nautical twilight;

d) integrated weight line – all longline vessels to use integrated weight line which is capable of achieving the CCAMLR standard sink rate (currently >0.2 metres per second). Sink rate trials to meet this requirement will be undertaken before the vessel enters the Fishery;

e) 100% observer coverage - 2 full time observers would be required on each trip and duties would include the monitoring of wildlife interactions;

f) paired streamer lines - use of streamer lines (with specifications to type and dimensions of streamer line) to scare birds away from gear;

g) ‘brickle curtain’ – this device was designed and developed by Petuna Sealord Pty Ltd (and subsequently adopted by CCAMLR) will be deployed to discourage birds from accessing baits during the haul of longlines;

h) prohibition on the use of plastic packaging bands - to prevent ingestion of or entanglement in the debris by seabirds or marine mammals; and

i) minimisation of lighting – to reduce the risk of seabirds colliding with the boat.