Fish diversity, composition, and guild structure influenced by the environmental drivers in a small temporarily closed tropical estuary from the western coast of India

• Published in: Environmental science and pollution research international Vol. 30; no. 50; pp. 108889 - 108906
• Main Authors: Benjamin, Liya Vazhamattom, R, Ratheesh Kumar, Padua, Shelton, Bhavan, Sreekanth Giri
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2023; Springer Nature B.V
• Subjects: Algae; Anthropogenic factors; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Carnivores; Chlorophyll; Detritivores; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Estuaries; Feeding behavior; Fish; Fisheries; Fishing; Freshwater fish; Geographical distribution; Guilds; Human influences; Marine fish; Mugilidae; Omnivores; Research Article; Salinity; Salinity effects; Species diversity; Waste Water Technology; Water Management; Water Pollution Control; India; Feeding guild; Spatio-temporal variation; Fish assemblage; Chettuva estuary; Salinity
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-023-29476-8

Globally, small temporarily closed estuaries are the least considered for fisheries assessment and management due to a low scientific priority and regional importance. However, these ecosystems are highly exposed to anthropogenic pressures and may deteriorate without assessing its aquatic resources. In this study, fish diversity and guild structure of Chettuva—a temporarily closed tropical estuary in the western coast of India—was investigated. A total of 70 fish taxa belonging to 32 families were recorded with the quantitative predominance of families; Mugilidae, Cichlidae, and Leiognathidae. Family Carangidae had the highest species diversity (seven species), followed by Clupeidae and Mugilidae (five species). Ecological guild assessment revealed that the immigrating marine fish species (marine estuarine opportunist (34 species) and marine estuarine dependent (13 species)) dominated the guild structure over the estuarine resident species (seven species). The marine species were found all along the saline gradient and throughout the sampling period indicating the salinity ingress towards the estuarine zone throughout the year. Carnivores and omnivores were the major feeding mode functional guilds in terms of diversity, whereas detritivores dominated in numerical abundance throughout the salinity gradient. The major environmental drivers of the fish assemblages in the estuary were salinity and chlorophyll a. The distribution of freshwater fishes and estuarine resident species was connected with the rising primary productivity as the majority of fishes rely on the algae for feeding, whereas marine estuarine dependent and marine estuarine opportunist species occurred in areas with the highest salinity concentrations.