Study on selectivity of different mesh size gillnet for Nemipterus virgatus in South China Sea

Nemipterus virgatus gillnet is one of the main fishing gears in South China Sea. According to the theory of maximum likelihood method of gillnet selectivity that rose in resent years, this paper uses the Normal, Gamma and Lognormal selectivity models, which are commonly used to describe gillnet selectivity curve, to analyze the catch data of Nemipterus virgatus from simultaneous fishing with 45, 50, 55 and 60 mm mesh sizes of gillnets in 1992. The results show that Lognormal model equation provide an adequate description for the selectivity curves of Nemipterus virgatus gillnet in South China Sea.