Assessment of Environmental Influences on Fecundity of Blackchin Tilapia (Sarotherodon Melanotheron) in Selected Coastal Lagoons of Ghana

Abstract

Coastal lagoons provide small-scale fisheries as a source of livelihood for coastal dwellers. Unfortunately, anthropogenic activities in Ghana are greatly degrading these lagoons which also serve as habitats for fish, including blackchin tilapia (Sarotherodon melanotheron). Yet, scientific information on the influence of these degraded lagoons on fish in Ghana is presently scarce. Given that S. melanotheron forms the mainstay of brackishwater fisheries in Ghana, this study was therefore carried out to assess environmental influences on fecundity of S. melanotheron in selected coastal lagoons of Ghana. A total of 744 fish from five selected lagoons were sampled for fecundity during the major breeding season (March – May). Within the same period, physicochemical parameters were measured monthly. Stomach content analysis was conducted to determine the diversity of food items consumed by S. melanotheron. Results showed significant variations (p < 0.05) in both fecundity and physicochemical parameters across the five lagoons. Among these physicochemical parameters, temperature, pH, dissolved oxygen, salinity, biochemical oxygen demand and food diversity markedly influenced fecundity (R2 = 0.98). By inference, environmental conditions play a remarkable role in the dynamics of reproductive performance of S. melanotheron. The negative impacts of these environmental factors on the reproductive capacity of S. melanotheron threaten the sustainability of lagoon fisheries in Ghana with consequences for food security. Hence, strict environmental management and conservation measures such as proper waste management should be instituted to discourage deleterious anthropogenic activities carried out around water bodies in Ghana