Evaluating the selective performance of gillnets used in a tropical low brackish lagoon south - western, Nigeria.

The result of the investigations of evaluating the selective performance, aspect of design and operation of gillnet used in Lekki lagoon between March, 2006 and February, 2008. The gillnet was the most abundant and constituted 50.04% and 48.74% of the fishing gears in the Lekki lagoon for March 2006 to February 2007 and March 2007 to February 2008 respectively. It was estimated that the 514 gillnet canoes produced a total of 218.73t fish at a low rate of 0.43t canoe/year. The catch per unit effort (CPUE) (kg/canoe/month) range between 14.2kg and 23.0kg with a mean value of 18.9± 2.91. The 30 - 45mm, 50 - 70mm and 75 - 180mm gillnet sizes caught an average of 2.05kg, 2.19kg and 2.32kg fish per canoe per day respectively. Monofilament gillnets caught more fish (by weight) than multifilament gillnets. The performance of gillnet was positively influenced by the improvised poles and concrete sinkers. To provide an overall (aggregated) effect of gillnet on the fish assemblage, multi - species selection curve for 40mm, 50mm and 75mm showed mean retention length of 135mm, 170mm and 235mm respectively. (Journal of American Science 2009;5(7):49-52). (ISSN: 1545-1003).