Fish diversity, abundance and fishing activities in the upper Ekole River, Bayelsa state, Niger Delta, Nigeria

Abstract

A thirty-six weeks investigation was carried out to determine the diversity and abundance of fish fauna and fishing activities of the Upper Ekole River in Bayelsa State. This research work was aimed at providing information on the fish stock and fishing gears used by fisher folks in this River. During the survey, fish samples were randomly collected from fisher-folks twice weekly from five sampling stations along the River. The fishes collected were counted, measured, and scientifically identified. Fishing gears used among fisher folks were identified such as cast nets, gill nets, seine nets, drag nets, drift nets, atalla (lift net), gura nets, clap nets, long-lines, hooks and lines, round traps, drum traps, non-return valve traps, cutlasses and machetes. Species diversity and abundance were analyzed using analysis of variance (ANOVA P<0.05) and Pearson correlation (2 tailed). The highest mean (31.39 ±77.53) in station B and the least mean (21.88 ±27.96) in station E of the Catches, while Relative Abundance highest mean (11.76 ±10.90) in station D and least mean (10.98 ±9.37) in station E; while in Species Diversity highest mean (2.09±0.94) in station A, and least mean (2.00 ±1.06) in station B. The diversity and relative abundance were determined using standard methods. Results revealed that, the River was composed of 70 species from 37 families, 16 orders and 52 genera from a total catch of 44,124. Fish species diversity was reported highest in Mormyridae (15.71%) and least in Nephropidae (1.43%) amongst others. The fish relative abundance was highest in Kryptopterus bicirrhis (16.42%), Marcusenius senegalensis (0.88%), Chrysichthys aluuensis (0.41%), Marcusenius cyprinoides (0.22%), and least in Chaceon maritae (0.01%).