Fishing Capacity Comparison of Different Types of Gillnet in the Liaodong Bay

Abstract:

In order to improve the fishing techniques and management level of offshore fishery resources, promote the implementation of National Marine Fishing Gear Catalog, selectivity among single gillnet (with the mesh sizes 40 mm, 50 mm, 60 mm), double gillnet, trammel gillnet and productive fishing gear (control group) was compared in the Liaodong Bay during October to November 2014. The results showed that the catch species of all experimental and productive fishing gear was between 6 and 9; the dominant species of experimental and productive fishing gear were Oratosquilla oratoria (dominance decreased with the increased mesh size) and Lateolabrax japonicas (dominance increased with the increased mesh size). There were significant differences on yields of the same type nets with different mesh size (P=0.0003, P=0.001, P=0.002), compared the CPUE of 60 mm with 40 mm, the single gillnet is 800%, the double gillnet is 650% and the trammel gillnet is 500%; but the influence on catch yields of the different type nets with same mesh size was relatively small. The average similarity of intra-group catch composition of the network was: single gillnet 59.24%, double gillnet 62.63%, and trammel gillnet 66.51%; Meanwhile, the average similarity of the inter-group was 71.44%, 67.50% and 70.58% respectively; The species which had the highest contribution to intra-group and inter-group average similarity were O. oratoria and L. japonicas. With the increasing of mesh size, the proportion of the catch the proportion of juvenile in the catch of all types of gillnets showed a decreasing trend.