Abstract

Characteristics of artisanal fisheries in the upper reaches of Bonny Estuary were investigated for a period of six months from December 2014 to June 2015. Data were collected from randomly selected fishermen from five communities, viz., Bodo, Kpor, Bomu, Lewe and Gbe, using interview and open ended structured questionnaire. The research was carried out to ascertain the fish existed in the study area, types of gear, and methods of fishing, preservation and marketing techniques. The mean values of physico-chemical parameters such as temperature, dissolved oxygen (D.O), salinity, pH, turbidity, and biological oxygen demand (BOD) were 30.47±1.34?C, 8.64±1.24 mg/l, 16.4±5.78 ppt, 7.66±0.76, 117.0±16.9 NTU and 4.94±2.66 mg/l, respectively. A total of 52 fish species belonging to 24 families were identified and the species diversity and their abundance were determined. Tilapia guineensis was the highest in number (190) with 4.0% of abundance, while Sphryraena afra was the least in number (9) with 2.0% of abundance. The dry season (December–February) recorded the number of 2,772 (57.7%) fin fishes, while the wet season (April–June) found 2,028 (42.3%). The mean number of fish caught was highest in station 2 and lowest in station 4. The physico chemical parameters were within the acceptable limits for fish growth in brackish water ecosystem. The study revealed that the gear commonly used by the fishermen include cast nets, drag nets, hook and line, and traps, while the crafts used were mainly dug-out canoe and non-motorised boat. It also revealed that the constraints responsible for the low catch and poor standard of living of the fishermen as observed include high cost of gear materials, poor condition of boat, no access to credit facilities, destruction of nets by engine boat and environmental pollution. In view of the negative impacts that the aforementioned factors have on the fishermen, it is necessary to implement an effective management of the fisheries through proper enforcement and environmental laws and policies to safeguard and conserve the aquatic biota from going into extinction as well as restoring the source of livelihood to the fishermen in the area under investigation.

Keywords

Fish composition, Upper reaches, Bonny estuary, Nigeria, Dissolved oxygen, Biological oxygen demand, Catch per unit effort, Exploitation, Conservation, Preservation, Livelihoods, Artisanal fisheries, Parts per thousand, Physico-chemical parameters, Environmental laws