Spatial and Temporal Variation of Fish Assemblage Associated with Aquatic Macrophytes in Three Small Lagoons of the SOUTH-Eastern, Côte d’Ivoire

Abstract

Aquatic plants play a crucial role in an aquatic ecosystem partly because these plant communities provide suitable habitats and food items to other aquatic organisms especially fish. The purpose of the present study was to examine spatial variation in fish assemblage structure associated with aquatic macrophytes in Ono, Kodjoboue and Hebe lagoons, three small lagoons of Côte d’Ivoire. Fish were monthly sampled from September 2014 to August 2016 using traps, gill nets, harpoons and hawks. The abiotic parameters namely temperature, transparency, pH, total dissolved solids, conductivity, dissolved oxygen, ammonium-nitrogen, nitrate, nitrite and phosphate were recorded for the characterization of the water mass in the lagoons. Significant variation in water parameters was observed among the sampling lagoons, except for nitrite and ammonium-nitrogen. However, no significant different was obtained between Kodjoboue and Hebe lagoons. A total of 42, 35 and 37 species were recorded respectively in Ono, Kodjoboue and Hebe lagoons, with Perciformes (22 species), Siluriformes (8 species) and Osteoglossiformes (7 species) being the most diverse Orders. Habitats with highly amounts of macrophyte cover provide the optimal environment for many fish and hence, increase the taxonomic richness, abundance, diversity and equitability. The multivariate analysis showed that temperature, dissolved oxygen, nitrate, phosphate, pH and ammonium-nitrogen and macrophyte were key environmental variables and played important roles in determining species composition of fish assemblages.