An Assessment of Fish Assemblages in Peripheral Lotic Habitats of the Caroni Swamp, Trinidad

Luberson Joseph; Ryan S. Mohammed; Rakesh Bhukal; Amy E. Deacon

An Assessment of Fish Assemblages in Peripheral Lotic Habitats of the Caroni Swamp, Trinidad

Luberson Joseph^1,4,*, Ryan S. Mohammed¹, Rakesh Bhukal^2,3, and Amy E. Deacon¹

¹The University of the West Indies, Department of Life Sciences, Faculty of Science and Technology, St. Augustine Campus, Trinidad and Tobago. ²The University of the West Indies, Faculty of Medical Sciences, School of Veterinary Medicine, St. Augustine Campus, Trinidad and Tobago. ³The University of the West Indies, Faculty of Food and Agriculture, Departmnt of Food Production, St. Augustine Campus, Trinidad and Tobago. ⁴Oklahoma State University (OSU), Department of Integrative Biology, College of Arts and Sciences, Stillwater, OK 74077, USA. *Corresponding author.

Caribbean Naturalist, No. 85 (2022)

Abstract
To fully understand the biodiversity of protected areas and the threats that they face, it is vital to monitor the habitats immediately adjacent to their borders. In this study, we assessed the fish assemblages of inland peripheral habitats of the Caroni Swamp Protected Area, Trinidad. We sampled each of 3 rivers that flow into the Caroni Swamp—the Caroni, Cunupia, and Guayamare rivers—at 3 locations of varying distance from the border of the protected area. A sample consisted of cast nets and fish traps deployed over 2 days. In total, we identified 205 fishes representing 19 species and 13 families. Cichlidae was the most dominant family and made up 65.36% of the total fish individuals captured. The introduced tilapia Oreochromis mossambicus was the most abundant species across all sites (33.17% of the fish recorded), followed by the native cichlid Andinoacara pulcher (14.15%). Diversity (species richness and Shannon index) varied considerably among sites, but neither measure varied consistently between rivers or with distance from the protected area. Spearman’s correlation indicated that levels of dissolved oxygen were positively correlated with fish abundance (P = 0.004) and richness (P = 0.02) at our sites. We also detected a significant positive correlation between both salinity and temperature on fish abundance (P < 0.05), but no relationship with either diversity metric. A PERMANOVA showed no significant difference in fish assemblages’ composition (P > 0.05) among sampling sites. These findings confirm that peripheral habitats of the Caroni Swamp support important biodiversity, yet they may also be acting as a source of invasive tilapia for downstream habitats. We recommend that these overlooked habitats be incorporated into future management plans for the Caroni Swamp, as they are closely connected in terms of both the biodiversity they support and the threats that they faceitability models used for the conservation management of this species.

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