acta satech Journal of the Life & Physical Sciences Babcock

Comparative studies on the catch selectivity of galvanized wire gauze trap from fresh and brackish water tropical creeks in south-western Nigeria
* Babatunde E. Emmanuel and Olojede, E.T.
Department of Marine sciences,University of Lagos, Akoka-Yaba,Lagos

The comparative studies on the catch selectivity of galvanized wire gauze trap from fresh and brackish water creeks in the south western; Nigeria was investigated between October, 2006 and March, 2007. Water samples from the two creeks (Abule - eledu and Iponri) were collected for physico chemical analysis. A monthly wire gauze trap catch composition was examined for 6 months. Salinity in the dry season in Abule Eledu creek has been associated with increased tidal seawater incursion coupled with reduced flood, water inflow from associated rivers and creeks. This was not so with Iponri creek which is totally freshwater creek throughout the year. The wire basket trap was highly selective for the crab, Callinectes amnicola in Abule Eledu creek. The effectiveness of the trap to catch different species in the two creeks made it a good small scale fishing gear. The soak time of twelve hours was affecting the fishing operation negatively by rendering the catch commercially value less. The dead fish attract more crabs which ended up feasting on the commercially important catch. The low species diversity noted in the creeks may be a reflection of fishing gear type used. Most fish specimen caught in this study from both creeks were juveniles meaning that the creeks served as nursery ground for these species. The longevity of the trap was related to the salinity of the area. The highest catch per Unit effort for Abule Eledu creek was in October (9 fish/trap/day) and the least was in January (2 fish/trap/day) while the highest catch per unit effort (CPUE) for Iponri creek was in March (12fish/trap/day) and the least was in December (6fish/trap/day). This trap is selective for both crabs and fin fishes and can be operated in both fresh and brackish shallow creeks.
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