Caroni Swamp RDI Project

Newsletter

Wetlands are important for the invaluable ecosystem ser-vices they provide, yet are threatened worldwide, with half of the World’s wetlands being lost since 1900. An important wetland ecosystem in Trinidad is the Caroni Swamp, located on the west-ern coast. This swamp is also the most heavily impacted in Trinidad, influenced by the capital city and landfill to the north, agricultural develop-ment to the east, and the pol-lution impacts from its name-sake river which drains almost ¼ of the surface area of the island. This swamp is domi-nated by mangrove forests with herbaceous swamp on its eastern boundary, and tidal mudflats scattered within and on the western boundaries of the swamp. This rich mosaic is critically important to the

people of Trinidad and Toba-go, as well as the organisms which make it home. The Caroni Swamp RDI project afforded us the opportunity to expand our knowledge of this critically important ecosystem. The funding resulted in 24 research projects producing invaluable information which will better inform manage-ment.

Research over the past three years focused on the ecologi-cal, social and economic im-portance of the swamp. Cam-era trapping was used to mod-el the factors which influence the persistence of the Crab-eating Racoon. Transects were used to estimate the densities of the Silky Anteater as well as Ruschberger’s Tree Boa and Caiman. Mist-netting was employed to examine bat com-munity composition in differ-

ent habitats, and to examine the importance of the swamp to overwintering passerine birds. The swamp was also extensively sampled for fish community composition while mangrove tree community composition along the Blue River, as well as leaf litter fall and decomposition rates were studied. The attitudes and responses of the people of Cacandi to the Swamp were examined, and public partici-patory GIS was used to not only determine where im-portant resources were derived by people in the swamp, but to indicate the effectiveness of current protection. Finally, the economic value of recrea-tional activity at the swamp, as well as the value of some of the resources and services within it were derived.

Biodiversity in the Caroni Swamp

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Inside this issue:

Research Projects 2 - 7

About RDI Fund 8

Contact information 8

ISSUE 3

FEBRUARY 2015

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©Luke Rostant

Contact information Phone: 1(868) 662-2002 Ext 83739 Fax: 1 (868) 663-5241 E-mail: caroniswamp.rdi@sta.uwi.edu

©Luke Rostant

© Sherazade Ali

Page 2 Issue 3

The Caroni Swamp is the main habitat site for one of the country’s national birds – the Scarlet Ibis Eudoci-mus ruber (Linnaeus 1758) in Trinidad. The species is featured on the Coat-of-Arms and one-dollar bill (Bildstein 1990), and supports an established eco-tourism industry at Caroni Swamp as a feature attraction (Frederick et al. 1990).

Increasing development pressures have negatively affected coastal wet-lands (Bildstein et al. 1991) such as Caroni Swamp which over recent years has seen increasing habitat destruction and human disturbance (Cuffy 2002, Juman and Ramsewack 2012). Sur-rounding communities are dependent on its resources for their livelihood and have been utilizing the area prior to the declaration of any Protected or Prohib-ited Areas (Gibbes et al. 2009, Bacon 2000). The declaration of restricted areas has resulted in decreased legal

resource use at the Swamp (Juman and Ramsewack 2012) which suggests that top down management focused on exclu-sion methods have failed to sufficiently protect the species (Bacon 2000). The Ibis was also – perhaps accidently – listed as a game species on hunting licenses up until the late 1980’s despite its protection under the Conservation of Wildlife Act 1963 and has remained a target species for many poachers over the years (Hislop and James 1990) due to cultural embed-ment; even after its removal from hunt-ing permits.

Under the RAMSAR Convention, the Caroni Swamp was declared a Pro-tected Natural Area (PNA) (Juman and Ramsewack 2012). PNAs require manage-ment plans that are properly thought out and include biological and cultural diver-sity; as well as take into account social and economic functions of the area (Thomas and Middleton 2003). Participa-tion methods can reduce tensions be-

tween natural resource managers and the public in decision making pro-cesses (Cox et al. 2014). This project utilizes participation methods along-side Geographic Information Systems (GIS) technology in order to engage a variety of stakeholders; both commu-nity participants as well as experts, in mapping the habitat sites where the Scarlet Ibis nests, roosts and feeds in Caroni Swamp. After a short orienta-tion on the project objectives, map-ping groups are asked to identify are-as Scarlet Ibis use on an aerial photo-graph of the Caroni Swamp with col-our coded stickers representative of nesting (yellow), roosting (red) and feeding (blue) sites. Additional data is collected on these identified points through semi-structured interview such as numbers observed, habitat characteristics, prey, predators, etc. Assessment of the effectiveness of existing Protected and Prohibited Areas will be done through compari-

son of identified points against the boundaries of the Forest Reserve, Wild-life Sanctuaries, and RAM-SAR Site. Survey data would be used to deter-mine the degree of overlap between local and expert knowledge collected through mapping exercis-es. It is expected that data collected from this project can facilitate better man-agement planning for PNAs within Caroni Swamp and be used as a foundation for further studies focused on the Scarlet Ibis within Caroni Swamp or along its wider habitat extent along the wetlands of the west coast of Trinidad.

Participatory GIS for Nesting, Roosting and Feeding habitat sites of the Scarlet Ibis Eudocimus ruber in Caroni Swamp, Trinidad. - Deanna Albert

Student Research Projects - http://www.caroniswamprdi.org/research.html

Page 3 Caroni Swamp RDI Project Newsletter

There is still little known about the Crab-eating Raccoon, Procyon cancrivorus (Cuvier, 1798) due its nocturnal be-haviour and its elusive conduct. It is a carnivorous mam-mal that can be found throughout Central and South America and also inhabits the island of Trinidad (Zeveloff 2002). The study focused on whether or not environmental factors influence the patch occupancy of the crab-eating raccoon in the Caroni Swamp, Trinidad.

The aims of this study are:

To obtain an overall estimate of occupancy of the crab-eating raccoon in the Caroni Swamp, Trinidad.

To investigate and determine whether patch size, dis-tance from nearest patch, vegetation density, canopy cover, density of crab holes and size of crab holes affect patch occupancy of the crab-eating raccoon (Chen et al. 2009; Zeveloff 2002).

Data collection occurred over a three month period from September to November, 2014. In order to capture the presence of the target species camera trapping was used. Camera trapping is a non-invasive method to survey mammal populations and is an idyllic choice for survey-ing cryptic species (Cove et al. 2013). The camera traps were placed at a total of 32 random sites and environ-mental surveys were conducted at each site over the three month period. To analyse the data the program PRES-ENCE version 7.1 was used.

The occupancy of target species within a site is of consid-

erable interest in ecology and can be used in monitoring programs for mammals since the occupancy data can be used prior to making inferences about the distribution and popu-lation change of the species (O’Connell et al. 2002). The data gathered from this project can be used as baseline data for future research and can contribute to the awareness and conservation of the species.

Patch Occupancy of Crab-eating Raccoons in the Caroni Swamp, Trinidad - Laura Baboolal

Student Research Projects - http://www.caroniswamprdi.org/research.html

©RDI Caroni Swamp Project

Page 4 Issue 3

The land crab Ucides cordatus (Linnaeus, 1763) is a semi-terrestrial species that is common to Neotropical mangrove for-ests; it is an important resource for the artisanal fisheries. This paper aims to evaluate the population structure and density of U. cordatus in the Caroni swamp Trinidad using field survey and social survey. Three sites were selected differing in accessibility and harvesting

history. Site A was accessible, Site B semi- accessible and site C non-accessible or re-served. U. cordatus was collected for 9 days at 5 hours per day during April 2014. Alto-gether, 227 specimens were collected (79 male and 148 females). Carapace size ranged from 69-8.97cm and 5.66-8.75cm for males and females respectively, and the weight for males and females ranged from 75-318g and 81-227g for males and females

respectively. There was no significant difference in the sizes of crabs for the three sites all the mean comparison showed a P value 0f >0.05 with a 95% confidence level. The overall popula-tion density was 0.9crabs/m² and popu-lation density was much higher in site C (0.36crabs/m² than in site B (0.29crabs/m²) and A (0.25crabs/m²) with the lowest population density. The general crab biomass was 49.67g/m² and biomass was higher in site C (61.56g/m²) than B (46.98g/m²) and A (40.48g/m²).For the social survey 51% of the respondents including both har-vesters and consumers have noticed a decline in the population of hairy crab while 49% believed that the population is increasing. However, 72% agreed to the formulations of policy to protect U.cordatus. In conclusion some conser-vation measures like moratorium and during the mating seasons, implementa-tion of regulations like allowable har-vested size and constant monitoring that can be taken to conserve and pro-tect U.cordatus in Trinidad and Tobago.

found for the site 7 which corresponds to 25.24% of the total specimens gathered, followed by the site 6 and 7 with 20.27%. Biomass ranged from 0.09 to 5.30g /m2, with a mean of 2.33g/m2. Mollusca, poly-chaeta and decapoda clearly predominated in the total biomass, contributing 56.05,

During April-May 2014, sampling was carried out in the Blue River in the Caroni Swamp, Trinidad to compare the spatial distribution of benthic mac-ro-invertebrates in relation to environ-mental variables and also to come up with an index of disturbance for each selected site. Macro-invertebrates col-lected were identified into family level. A total of 7 macro-benthic taxa were identified. Variation in the abundance and the biomass of macro-invertebrates were found for the 9 selected stations. Abundance varied from 43.48 to 880.43 ind./m2, with a mean of 356.24ind./m2. Highest density was

24.61%, and 10.91% respectively. Mul-tivariate statistical analyses were applied to identify environmental gradients and describe distributional patterns of ben-thic macro-invertebrates (numbers and biomass) in sub-tidal sediments of the Blue River. This revealed two main groups, particularly related to the depth and temperature. The Abundance Bio-mass Comparison method used for the index of disturbance revealed that the middle of the Blue River, which corre-sponds to site 5, would appear severely disturbed. The mouth of the Blue River presents a high abundance and biomass of molluscs.

Inventory, densities and distribution of benthic macro-invertebrates along the Blue River in the Caroni Swamp, Trinidad - Fritzner Agrossous

Investigating and Evaluating the population Dynamics of Ucides cordatus (Hairy Crab) in the Caroni Swamp, Trinidad and Tobago - Waisea Bolatolu

Student Research Projects - http://www.caroniswamprdi.org/research.html

© Sherazade Ali

© Waisea Bolatolu

Page 5 Caroni Swamp RDI Project Newsletter

The Blue Land Crab is a semi-terrestrial species that is found in neo-tropical regions such as the Caribbean and the Americas. It is commercially harvested in countries such as Venezue-la, Puerto Rico, the Bahamas and Bra-zil. This species inhabits coastal envi-ronments where it lives in burrows above the high tide line. The Blue Land Crab is an important member of estuarine ecosystems where they help shape the composition of plant com-munities through its predation on seeds and seedlings. They also contrib-ute to nutrient recycling, and its bur-rows facilitate the transportation of water, minerals and oxygen.

Recent research, however, has shown that the Blue Land Crab is over-exploited and endangered in places such as Puerto Rico, Venezuela and the Bahamas. The Blue Land Crab is cur-rently on a National List of Threatened and Overexploited Species in Brazil. The status of the species in Trinidad and Tobago, however, is unknown since no official data exists on its popu-lation structure and distribution. Con-sequently, this research was undertaken with the purpose of assessing the popu-lation status of this species at the Caro-

ni Swamp where it has been harvested for decades. Fieldwork was conducted during the months of September 2014 and January 2015 by Keimraj Sookhoo as part of the MSc in Biodiversity and Sustainable Development in the Carib-bean, and was supervised by Dr. Luke Rostant of The University of the West Indies.

Population density and size struc-ture was investigated at four sites- two protected sites, one minimally harvest-ed site and one intensely harvested site. Burrow counts were used to estimate population density, and traps were set at each site to capture crabs for size measurements. Traps were set on after-noons and checked the next morning since the Blue Land Crab is most active during the afternoons and early morn-ings. Carapace length and width of each crab was measured. Mean popula-tion density, mean carapace width and length was calculated and analysed for each site. It is expected that these anal-yses will identify sites that are over-exploited.

A habitat survey was also done to evaluate the influence of habitat quality on crab density and size. This included counts of the number of trees and spe-

cies at each site along with a calcula-tion of the Shannon diversity index. Stand basal area and leaf litter stand-ing stock was also measured for each site. Five leaf samples were collected from each site and dried in an oven to derive the dry weight. Analyses were conducted to evaluate the relationships between vegetation characteristics and crab populations.

A social survey was also done in the village of Cacandee with Blue Land Crab harvesters and consumers. Open and semi-structured interviews were used for harvesters while question-naires were distributed to consumers. Questions were designed to evaluate the socio-economic importance of the Blue Land Crab to surrounding com-munities and to gauge the public's opinion on the status of the Blue Crab populations in the Caroni Swamp.

It is hoped that the findings of this research will improve our under-standing of the population status of the Blue Land Crab at the Caroni Swamp and can help inform wildlife management policies that can assist in the conservation and sustainable growth of our Blue Crab populations.

Population status of the Blue Land Crab, Cardisoma guanhumi, in the Caroni Swamp, Trinidad and Tobago - Keimraj Sookhoo

Student Research Projects - http://www.caroniswamprdi.org/research.html

©Keimraj Sookhoo

Page 6 Issue 3

Within the mangrove system macrofauna are a vital part of the mangrove food web and are influential in the energy flow within the mangrove ecosystem (Nordhaus, et al. 2009). The organisms that colonize and grow on mangrove roots are referred to as epibionts (Wahl 1989). Epibionts typically settle and grow on any living, solid bare surface in mari-time ecosystems (Wahl 1989). In man-groves, littoral mangrove roots are the sole local solid area that is not impacted by significant sedimentation and repre-sent the model habitat for algal and in-vertebrate epibionts (Ellison and Farns-worth 1992). Root macrofauna commu-nities are impacted by abiotic factors such as temperature, salinity, dissolved oxygen, pH, nitrates and phosphates. Water qual-ity in the mangrove ecosystem can have

impacts on the macrofauna which exist, impacts including the types and number of macrofauna that occur at a given area. Macrofaunal assemblages are one of the most significant indicators of ecological health in coastal and estuarine environ-ments (Vazirizadeh and Iman 2011). Sam-pling was done along the main channel of the Caroni Swamp, utilizing three 1mx1m quadrats along a 5m transect into the man-grove at 20 sites along the channel. Along each transect root length and radius was measured and the number and types of macrofauna within each quadrat was rec-orded. Water quality measurements were also recorded using the YSI metre. The objective of this study is: To investigate the impact of water quality on community den-sity, species diversity and species richness of root macrofauna in the Caroni Swamp,

Trinidad. From the results collected it can be observed that the majority of species recorded were observed at the middle reaches of the channel. This area may be ideal due to the degree of space for colonization as well as stable water quality conditions. The main abiotic parameters influencing these sites were dissolved oxygen, nitrates, phosphates and pH. The majority of studies conducted on macrofauna in mangroves have focused on benthic macrofauna and to small degree; root macrofauna therefore further studies should be carried out on root macrofau-na specifically in the Caroni Swamp. Focus should be given to the mangrove oysters as these are the most dominant species and can be more easily and quickly observed due to their abundanc-es. Studies can be conducted in the Caroni Swamp to use mangrove oysters as an indication of the health of the ecosystem

The impact of water quality on root macrofauna succession in the Caroni Swamp, Trinidad - Errin Chong

Student Research Projects - http://www.caroniswamprdi.org/research.html

©RDI Caroni Swamp Project

Page 7 Caroni Swamp RDI Project Newsletter

Mangroves are tropical marine plants which are regarded as productive terres-trial ecosystems worldwide (Lacerda et al. 2002). About 50 percent of net pri-mary productions found in mangroves are being exported as organic matter to the ocean (Robertson and Alongi 1995). Mangrove leaves are the biggest part of the primary litter production that are available to consumers and have a significant contribution towards the coastal food chain (Dewiyanti 2010). Identifying decomposition rates of mangrove leaves is important in understanding how organic detritus and nutrients can enrich coastal seas. Leaf decomposition rates in mangroves in Trinidad have never been studied hence the research thesis investigates the decomposition rates of mangrove leaves in Trinidad particularly the de-composition rate of Rhizophora man-gle, Laguncularia racemosa and Avicen-na germinans. Leaves were investigates along the Blue River, Caroni Swamp. The objectives of the study were to 1) investigate the rate of decomposition of the three (3) species at six different sites and 2) determine if there is any positive correlation between remaining leaf litter and physico-chemical parameters e.g. salinity, dissolved oxygen, tempera-ture, electrical conductivity and pH.

The litter bag method was used to study the decomposition of the leaves.

Leaves of the three species were collect-ed from 6 plots along the Blue River; oven dried and packed in nylon bags.

Total of 126 bags were buried at 10cm deep at each plot

Environmental parameters were meas-ured during the collection of the bags.

The mass of remaining leaves for all three species in the Caroni Swamp for the six sites showed rapid mass loss. The average percentages of decom-posed litter were 23.1% ±8.6 for R. mangle, 26.45% ±9.0 for L. racemosa and 32.06% ±5.1 for A. germinans. The average half-life differed among species at 156, 169 and 89 days for R. mangle; L. racemosa and A. germinans,

respectively. The average decay con-stants for the three species following the initial mass loss were 0.005 d-1 for R.mangle, 0.005 d-1 for L. racemosa and 0.008 d -1 for the A. germinans. The ANCOVA test show that sites 4, 5, and 6 showed significance differences in decay of leaf material compared to sites 1, 2 and 3 which showed similari-ties in leaf decay. The Krus-Wallis test showed that salinity and electrical con-ductivity showed significant difference between sites. The linear test showed that there was significant correlation between salinity, electrical conductivity and the remaining litter for the man-grove species particularly the R.mangle and L.racemosa respectively.

Percentage of litter decomposed for each species showed significant difference in sites 4, 5 and 6 (near river mouth) between three species which could be attributed to location of the site along the river where salinity and conductivity gradient may be present. Decomposition rates of the three man-grove species were high in the begin-ning and lower at the end of the pro-cess. The first month, decomposition rates were more attributed to leaching accompanied by microbial actions. Decomposition is slower in the second phase which could be due to particles that are more resilient to bacterial activ-ities and could form humic materials of complex structure (Hossain and Hoque 2008). Comparison of decomposition rates showed that A. germinans had slight higher average decay rates of decomposition compared to R.mangle and L.racemosa in all sites except site 1. Major factors that contributes to the differences in decomposition rates between the three species is due to frequent inundation and as well as chemical constitution of leaves for each species and also another factor is the faunal community structure particular-ly the influence of earthworms which was observed during the study.

Site 1 showed much higher decomposi-tion rates for the three species. A main reason could be that site 1 is more in-

undated nearly or most times. Site 4 has the highest decomposition rates for A.germinans this could be due to its location closer to the mouth of the river and water bodies that can be affected by physical tide process. Site 6 showed lower decomposition rates which could be due to higher salinity compared to other sites. Decomposi-tion rate constants for the three species in the Caroni Swamp indicate that the rate of decomposition along the Blue River was medium, which is quite within the range of other studies in the tropical and subtropical regions show-ing that the decomposition process tends to be more similar when in simi-lar environmental conditions. The positive correlation of salinity and conductivity with the remaining leaf litter of the R. mangle and L. racemosa indicates that increase salinity and electrical conductivity increases re-maining litter thus it decreases decom-position rates particularly for the R. mangle and L. racemosa.

In conclusion study supports the hypothesis that there is a significant difference between the three man-groves species, the A. germinans showed higher rates of decomposition indicated by the slight increase of the decay constants from the remaining litter compared to the R.mangle and L.racemosa. The major factor that contributes to the differences in de-composition rates between the three species in all six sites is due to frequent inundation, chemical constitution of leaves for each species e.g. Nitrogen and tannins as well as salinity and electrical conductivity gradient. The data does not support the hypothesis that higher percentage of remaining litter positively correlates with parame-ters such as temperature, dissolved oxygen, and pH, however it positively correlates with salinity and electrical conductivity which shows that increase of salinity and electrical conductivity increases litter remaining indicating a decrease of decomposition rates.

Decomposition of Mangrove Leaves along the Blue River, Caroni Swamp, Trinidad- Mary Tahu

Student Research Projects - http://www.caroniswamprdi.org/research.html

The UWI-Trinidad and Tobago Research and Development

Impact Fund

As we embark upon a new UWI Strategic Plan 2012-2017, one of the priori-

ties for the UWI St. Augustine Campus is to position our Campus as the leader in producing

relevant and impacting research. The University of the West Indies has for several decades pro-

duced outstanding research and sought to communicate new knowledge through teaching, con-

ferences, public lectures, consultancies and public service. In today’s highly competitive environ-

ment, however, this has become even more essential if the university is to distinguish itself and

provide leadership in new and emerging areas linked to national and regional development.

So how do we strengthen the synergy between scholarship and development impact? The appli-

cation of research, the engagement of key stakeholders throughout the process and the effective

communication of research outputs to diverse audiences are all critical elements in this process,

in addition to the availability of dedicated research funding.

The focus of the RDI Fund is, therefore, to support projects that address pressing development

challenges and that will achieve recognizable and substantive impact in the short and medium

term (3-5 years). Emphasis will be placed on: multi-disciplinary research, collaboration and stra-

tegic partnerships, participation of PhD students and/or post-doctoral researchers, a focus on

research-directed action and impact on policy, practice, products and/or services, contribution

to shaping the intellectual discourse on a policy issue of national/regional importance,

knowledge dissemination and stakeholder engagement.

It is anticipated that through the methodological approach and execution of its projects, the

RDI Fund would foster a greater appreciation in our stakeholders, of the value and impact of

UWI research, innovation and knowledge transfer.

The University of the West Indies St. Augustine

WEBSITE: HTTP ://WWW .CARONISWAMPRDI .ORG/

Prof John Agard– Project leader

Dr Luke Rostant– Co-project leader

Ms Lee Ann Beddoe– Internal project manager

Dr Howard Nelson– external project collaborator

Dr Bheshem Ramlal– Co-lead on GIS/Remote Sensing aspects of Caroni Swamp

Caroni Swamp RDI Project Team

Contact information Phone: 1(868) 662-2002 Ext 83739 Fax: 1 (868) 663-5241 E-mail: caroniswamp.rdi@sta.uwi.edu

HTTP ://WWW .CARONISWAMPRDI .ORG/

©Luke Rostant © Kamal Mahabir

© Sherazade Ali

© Rachel Campbell

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