Assessement of Fish Diversity in Relation to Fishing Gear Efficiency in Tagwai Lake Minna, Nigeria

Abstract

The fish fauna of Tagwai Lake, Niger State, Nigeria was studied between February and August, 2016. The catch assessment was conducted at the landing site bi-weekly. Simple descriptive statistical tools such as simple percentage, frequency counts were used to analyze data obtained. A total of 53,442 fishes belonging to 7 families and 8 species were identified namely: Tilapia zill, Sarotherodon galilaeus, Alestes dentex, Auchenoglanis occidentalis, Clarias gariepinus, Mormyrus hasselquistii, Chrysicthys auratus, and Odaxothrissa mento. In terms of number, the Family: Clupeidae dominated the catch, and contributed 46.98% to the total catch. This was followed by the Cichlidae (43%), Alestidae (7.03%), Bagridae (2.08%), Clarotidae (7%), Claridae (0.42%), Mormyridae (0.00%). In terms of weight, the Cichlidae family was dominant (40.84%) for the total weight of fish caught. Cichlidae was also the most diversified family, represented by 2 species. The results showed the species abundance to be: Tilapia zillii (21.96), Sarotherodon galilaeus (21.04%), Odaxothrissa mento (46.98%), Alestes dentex (7.033%) and Auchenoglanis occidentalis (2.08%) in Tagwai Lake. Cast nets and gill nets were the most productive fishing gear with a total catch of 33, 555 and 7095 fishes respectively. Hook-and-line yielded no catch. The predominantly used gear between the month of July and August were Trap nets (Wire trap and the Gura Malian trap) The dominant species in cast net collections was T. galilaeus (32.60%) while that of Gill net was O. mento (59.48%). As a management strategy for this Lake, fishing activities should be monitored periodically to avoid the use of inappropriate gear for fishing.