Biodiversity of Fishery Resources of the Cross River System: Implication for Conservation and Management

Abstract

This study aimed to assessing the biodiversity of fishery resources of the Cross River System with implication for conservation and management. Sampling was carried out once a month for twelve months (January to December, 2016) with fish gears such as cast net, drift net, gill net, local traps and hook and line. Twenty six genera of fish were identified belonging to 22 families consists of 22703 individuals collected from all the stations. The most dominant families were Clupeidae and Cichlidae with respective relative abundance of 17.69% and 13.16% while the family Osteoglossidae was the least contributing only 0.77%to the fish taxa. For seasonal distribution, Mugilidae, Clariidae, Cichlidae, Gobiidae and Sciaenidae were abundant in both wet and dry seasons while Clupeidae, Bathyclupeidae, Carangidae and Sphyraenidae were low in wet season but high in dry season. There was no significant seasonal difference (p>0.05) in fish biodiversity and abundance. Like other water bodies in the Niger Delta, the Cross River system was found to possess desired potential for fisheries exploitation considering its high fish species diversity, composition and abundance. Although pollution level was not measured in this study, the continuous discharge of wastes/effluents into the aquatic ecosystem may pose deleterious effect on the biodiversity and abundance of the resident biota. Therefore to ensure sustainable biodiversity, conservation and management of fishery resources, there is need for stringent regulation and prevention of untreated wastes/effluents discharged from households, farms and industries into the aquatic environment.