MORTALITIES AND EXPLOITATION RATES OF SOME COMMERCIAL FISHES LANDED BY ARTISANAL FISHERS IN EKPERIAMA, NIGER DELTA

Length-frequency data of 22 fish species sampled were collected randomly from the landings of artisanal fishers and analysed with the aim of estimating mortalities and exploitation rate of most landed fish species in Ekperiama along Ogbia Creek in Niger Delta. The data was fed into FiSAT (FAO- ICLAM Fish Stock Assessment Tool). Gears used in the area were identified through personal contacts and discussions with the fishers and were classified into various types (active and passive). Fishing gears consist mostly of gill net, drift nets hook and line, and traps. M/K (natural mortality to growth coefficient) ranged between 1.0 and 2.5 which is acceptable and makes the study valid for scientific interpretation and deduction. Fishing mortality values estimated was < 0.7 excerpt for Lutjanus agennes and Ilisha africana. Exploitation rate (E) estimated in this study are within optimum level indicating low fishing intensity which means that other activities such as oil exploration and exploitation activities, illegal refineries and sand drilling going on in the area are responsible for depletion of fish stock in the aquatic ecosystem. These factors could affect the physic-chemical properties of the aquatic ecosystem, thereby affecting the physiology and metabolism of the aquatic organism. It is therefore pertinent for the government to check and control these activities in the Niger Delta.