Preliminary Assessment of Major Tilapiine Fishes Exploited by Artisanal Gillnet Fishery in Lake Ayame I (Bia Basin, Cote d Ivoire)

Artisanal gillnet fishery was investigated in Ayamé I reservoir during a survey of 12 months. Mean value of Catch Per Unit Effort (CPUE) was 9.23±5.18 kg of fish per trip. Both commercially important tilapiine species, Sarotherodon melanotheron and Oreochromis niloticus, constituted >57% of gillnet catches. The von Bertanlanffy growth parameters (L∞ and K) computed from length-frequency data through the FiSAT software were (L∞ = 35.3 cm and K = 0.4 year-1) for O. niloticus and (L∞ = 33 cm and K = 0.55 year-1) for S. melanotheron. Resources status analysis by comparison of fishing mortality rates F with the target [(Fopt) and limit (Flimit)] ones, biological reference points indicated that S. melanotheron is overfished whereas, O. niloticus is exploited close to the optimum level. These results allowed us to suggest some management strategies for sustainable exploitation of the studied tilapiine stocks in the reservoir.