Revista de Biología Tropical ISSN Impreso: 0034-7744 ISSN electrónico: 2215-2075

The effect of seasonal and human pressure on macrobenthic fauna in the Caroni Swamp Ramsar Site, Trinidad and Tobago


Caroni Swamp
environmental quality assessment
ecological status
Pantano Caroni
evaluación de calidad ambiental
estatus ecológico

How to Cite

Kanhai, A., & Juman, R. (2018). The effect of seasonal and human pressure on macrobenthic fauna in the Caroni Swamp Ramsar Site, Trinidad and Tobago. Revista De Biología Tropical, 66(3), 1101–1117.


Human pressures have placed many tropical estuaries in developing countries under increased levels of stress. The Caroni Swamp Ramsar Site, the largest mangrove swamp along the west coast of Trinidad, has been subjected to high levels of anthropogenic impacts including hydrological alteration and pollution from land-based sources since the 1920’s. While most of these impacts have been well documented, limited information exists on the macrobenthic communities in the swamp. This study addresses the paucity of information. The macrobenthic fauna in the main waterways of Caroni Swamp was sampled at 12 locations using a Van Veen 0.025m2 grab, once in the dry (April) and wet (August) season of 2015 with a total of 144 samples. The samples were sorted, counted and species were identified to the lowest possible taxonomic level. A total of 55 taxa were identified with polychaetes being the most abundant taxa. The ecological status of the macrobenthos was assessed using AZTI’s Marine Biotic Index (AMBI) and the multivariate-AMBI (M-AMBI). Physicochemical parameters were measured with a YSI multiparameter metre. Chemical analyses were also conducted on nitrates, nitrites, ammonia and reactive phosphates using standard methods. Overall, AMBI characterised the Caroni Swamp as “slightly disturbed” with a macrobenthic community of “poor” ecological status according to M-AMBI. Generally, the quality of the environment improves from the dry season to the wet season. However, seasonal variations in AMBI and M-AMBI were found to be site specific as some showed improvement in ecological status and macrozoobenthos quality while others showed degradation from the dry season to the wet season. The stations to the north of the swamp showed improvement from the dry season to the wet season while the opposite was observed in the more southern stations. One notable characteristic of the swamp was the high levels of pollutants, particularly ammonia, recorded in one of its major waterways, the Caroni River. This is in contrast to the other waterways within the swamp which experience much lower levels of pollutant input from land-based sources. The assessment of the Caroni Swamp using AMBI and M-AMBI may be useful for informing management strategies to conserve the wetland and improve environmental quality.


Afli, A., Ayari, A., & Zaabi, S. (2008). Ecological quality of some Tunisian coast and lagoonlocations, by using benthic community parameters and biotic indices. Estuarine Coastal Shelf Science, 80, 269-280.

APHA, AWWA, WPCF. (1995). Standard Methods for the Examination of Water and Waste water, 19th ed. American Public Health Association, Washington, DC.

Bacon, P. (1970). The Ecology of Caroni Swamp. Special Publication. Trinidad and Tobago: Central Statistical Office.

Bigot, L., Gremare, A., Amouroux, J.-M., Frouin, P., Maire, O., & Gaertner, J. (2008). Assessment of the ecological quality status of soft-bottoms in Reunion Island (tropical Southwest Indian Ocean) using AZTI marine biotic indices. Marine Pollution Bulletin, 56, 704-722.

Borja, A., Dauer, D., Diaz, R., Llansó, R., Muxika, I., Rodriguez, J., & Schaffner, L. (2008). Assessing estuarine benthic quality conditions in Chesapeake Bay: A comparison of three indices. Ecological Indicators, 8, 395-403.

Borja, A., Franco, J., & Pérez, V. (2000). A marine biotic index to establish the eco-logical quality of soft-bottom benthos within European estuarine and coastal environments. Marine Pollution Bulletin, 40, 1100-1114.

Borja, A., Josefson, A., Miles, A., Muxika, I., Olsgard, F., Phillips, G., . . . Rygg, B. (2007). An approach to the intercalibration of benthic ecological status assessment in the North Atlantic ecoregion, according to the European Water Framework Directive. Marine Pollution Bulletin, 55, 42-52.

Borja, A., Muxika, I., & Franco, J. (2003). The application of a Marine Biotic Index to differ-ent impact sources affecting soft-bottom benthic communities along European coasts. Marine Pollution Bulletin, 46, 835-845.

Borja, A., & Tunberg, B. (2011). Assessing benthic health in stressed subtropical estuaries, eastern Florida, USA using AMBI and M-AMBI. Ecological Indicators, 11, 295-303.

Brinkhurst, R. (1971). A Guide for the Identification of British Aquatic Oligochaeta. Toronto: University of Toronto.

Brown, C. B., Hansell, J. R. F.., Hill, I. D., Stark, J., Smith, J. W. (1966) Land Capability Survey of Trinidad and Tobago # 1. Port-of-Spain, Trinidad.

Buchanan, J., & Kain, K. (1971). The Determination of Organic Matter in Sediments. In W. Holme, & A. McIntyre (Eds.), Methods for the Study of Marine Benthos (pp. 49-50). Oxford: Blackwell Scientific.

Central Statistical Office (CSO) of Trinidad and Tobago. (1995). Population and Housing Census 1990. Government of Trinidad and Tobago.

Cheung, S., Lam, N., Wu, R., & Shin, P. (2008). Spatio-temporal changesof marine macrobenthic community in sub-tropical waters upon recovery fromeutrophication. II. Life-history traits and feeding guilds of polychaete community. Marine Pollution Bulletin, 56, 297-307.

Clarke, K. R., & Gorley, R. N. (2006). PRIMER v6: user manual/tutorial (Plymouth routines in multivariate ecological research). Plymouth: Primer-E Ltd.

Cuffy, G. C. (1999). Seasonal use of a neotropical marsh by avifauna, Caroni, Trinidad. (M.Phil. Dissertation). Department of Life Sciences, University of the West Indies, St. Augustine, Trinidad

Deonarine, G. (1980). Studies on the Biomagnification of Some Chlorinated Hydrocarbons in a Neotropical Mangrove Swamp. (M.Phil. Dissertation). University of the West Indies, Trinidad.

Fauchald, K. (1977). The Polychaete Worms, Definitions and Keys to the Orders, Families and Genera, Los Angeles: Natural History Museum of Los Angeles County.

Feebarani, J., Joydas, T., Damodaran, R., & Borja, A. (2016). Benthic quality assessment in a naturally- and human-stressedtropical estuary. Ecological Indicators, 67, 380-390.

Grasshoff, K., Ehrhardt, M., & Kremling, K. (1983). Methods of Seawater Analysis, Germany: Verlag Chemie.

Henry, E. B. (1990). Climate variability and climate change- the role of small island states, for instance Trinidad and Tobago. Trinidad and Tobago Climate Document. Trinidad and Tobago: Meteorological Services.

Hyland, J., Balthis, L., Karakassis, I., Magni, P., Petrov, A., Shine, J., . . . Warwick, R. (2005). Organic carbon content of sediments as an indicator of stress in the marine benthos. Marine Ecology Progress Series, 295, 91-103.

Institute of Marine Affairs (IMA). (1999). Trinidad and Tobago Water Sector Institutional Strengthening Design and Implementation of the surface Water Quality Monitoring Programme for the Caroni River Basin. Draft Final Report-Surface Water Quality in the Caroni River Basin. Trinidad and Tobago: Water and Sewage Authority.

Institute of Marine Affairs (IMA). (2012). Water Quality Assessment at Williams Bay and Chagville Beach. Institute of Marine Affairs, Chaguaramas, Trinidad.

Intergovernmental Oceanographic Commission. (1982). The Determination of Petroleum Hydrocarbons in Sediments. Paris: UNESCO.

Juman, R., Bacon, P., & Gerald, L. (2002). Caroni Basin Case Study, Caribbean Basins, LOICZ (Land-Ocean Interaction in the Coastal Zone) Global Change Assessment and Synthesis of River Catchment/Island Coastal Sea Interaction and Human Dimensions, with a desktop study of Oceania Basins. LOICZ Reports and Studies, No.27. The Netherlands: LOICZ Texel.

Juman, R. A. & Hassanali, K. (2013). Mangrove Conservation in Trinidad and Tobago. In G. Gleason, & T. R. Victor, (Eds.), Mangrove Ecosystems: Biography, Genetic Diversity and Conservation strategies (pp. 35-64). New York: Nova Publisher

Kanhai, L., Gobin, J., Beckles, D., Lauckner, B., & Mohammed, A. (2013). Metals in sediments and mangrove oysters (Crassostrea rhizophorae) from the Caroni Swamp, Trinidad. Environmental Monitoring Assessment, 186, 1961-1976.

Kjerfve, B. (1981). Tides of the Caribbean. Journal of Geophysical Research, 86, 4243-4247.

Kjerfve, B., Perillo, G.M.E., Gardner, L., Rine, J., Dias, G., & Mochel, F. (2002). Morphodynamics of muddy environments along the Atlantic coasts of North and South America. In T. Healy, Y. Wang, & J.A. Healy (Eds.), Muddy Coasts of the World: Processes, Deposits and Functions (pp. 479-532). N.Y.: Elsevier.

Lee, S. (2008). Mangrove macrobenthos: assemblages, services and linkages. Journal of Sea Research, 59, 16-29.

Lotze, H. (2010). Historical reconstruction of human-induced changes in U.S. estuaries. Oceanography Marine Biology Annual Review, 48, 267-338.

Matsui, N., Meepol, W., & Chukwamdee, J. (2015). Soil Organic Carbon in Mangrove Ecosystems with Different Vegetation and Sedimentological Conditions. Journal of Marine Science and Engineering, 1404-1424.

Ministry of Environment of British Colombia. (1991). Guidelines for Interpreting Water Quality Data. Retrieved from

Muxika, I., Borja, Á., & Bald, J. (2007). Using historical data, expert judgement and multi-variate analysis in assessing reference conditions and benthic ecological status,according to the European Water Framework Directive. Marine Pollution Bulletin, 55, 16-29.

Nathai-Gyan, G. (2006). Restoration of the freshwater marsh ecosystem of the Caroni Swamp to improve foraging opportunity for the Scarlet Ibis (Eudocimus ruber). St. Augustine: University of the West Indies.

NOAA. (2016). Hypoxia . Retrieved from National Ocean Service :

Oram, B. (2014). Water Research Centre. Retrieved from

Paz-Ríos, C. E., Simões, N., & Ardisson, P.L. (2013). Intertidal and shallow water amphipods (Amphipoda: Gammaridea). Nauplius, 21(2), 179-194.

Pearson, T., & Rosenberg, R. (1978). Macrobenthic succession in relation to organic enrichment and pollution of the marine environment. Oceanography and Marine Biology, 229-311.

Phelps, H. O., (1997). Caroni Swamp Rehabilitation Study- Hydrology and Engineering. Report to the Inter-American Development Bank.

Rabalais, N., Turner, R. E., Justic´, D., Dortch, Q., & Wiseman, W. J. (1999). Characterization of Hypoxia: Topic 1 Report for the Integrated Assessment on Hypoxia in the Gulf of Mexico. NOAA Coastal Ocean Program Decision Analysis Series No. 15. Maryland: NOAA Coastal Ocean Program, Silver spring.

Sigovini, M., Keppel, E., & Tagliapietra, D. (2013). M-AMBI revisited: looking inside awidely used benthic index. Hydrobiologia, 717, 41-50.

Siung-Chang, A., Norman, P., & Dalipsingh, R. (1987). Caroni River Study: Organic Pollution. Chaguaramas: Institute of Marine Affairs.

Spagnolo, A., Punzo, E., Santelli, A., Scarcella, G., Strafella, P., Grati, F., & Fabi, G. (2014). Offshore platforms: comparison of five benthic indicators for assessingthe macrozoobenthic stress levels. Marine Pollution Bulletin, 82, 55-65.

USEPA (1995). The EPA Quality Criteria for Water. Retrieved from the United States Environmental Protection Agency :

Vaalgamaa, S., Sonninen, E., Korhola, A., & Weckstrom, K. (2013). Identifying recent sources of organic matter enrichment and eutrophication trends at coastal sites using stable nitrogen and carbon isotope ratios in sediment cores. Journal of Paleolimnology, 50, 191-206.



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