Efficiency and Selectivity of gillnet mesh sizes for assessing fish composition of Egbe Water Reservoir, Ekiti State, Nigeria

·        Adebola,O.T, Bello, A.O, Fagbenro, O.A and Sabejeje, T.A

 

·         Email:adebolaoluwatoyin@yahoo.com

·         Abstract: Comparism of five (5) different gillnet mesh sizes ranging from 50.8mm, 63.5mm, 78.2mm, 88.9mm, and 101.6mm was done at four (4) different sampling stations along the banks of the reservoir to evaluate the efficiency and selectivity of gillnet mesh sizes for assessing fish composition in Egbe water reservoir, between April, 2014 and January, 2016, they were designated as A (Odode), B (Church), C (Ayepe) and D (Dawodu). The nets were set at 6.00pm and hauling done in the morning at 8.00am, fishermen were well monitored to avoid sampling bias and ensure a constant fishing effort. The fishes were sorted into separate container based on gillnet mesh sizes and also species. The total length and weight of individual were taken, Simpson’s index, Simpson reciprocal index and Evenness were determined. The percentage composition by biomass fish landing was recorded. 31,905 fishes belonging to 7 species and 5 families were recorded. The most abundant family was the Cichlids represented by 3 major species, Oreochromis niloticus, Coptodon zillii, and Tilapia guineensis. All the net types captured all the fish species but the smallest gill net mesh size (50.8mm) captured a greater number than others, this shows that the smaller bar mesh nets were more efficient for capturing more fishes than other graded mesh nets, but should be discouraged for artisanal fishing activities in the study area, other gears like hook and line, cast nets and traps should be encouraged.