Turkish Journal of Fisheries and Aquatic Sciences
2017, Vol 17, Num, 6 (Pages: 1287-1296)
Gillnet Selectivity on the Small Yellow Croaker Larimichthys polyactis in the Southern Yellow Sea
2 Jiangsu Marine Fisheries Research Institute, Nantong, 226007, China
3 Key Laboratory of Fishery Ecological Environment Assessment and Resource Conservation in Middle and Lower Reaches of the Yangtze River, Freshwater Fisheries Research Center, Chinese Academy of Fishery Sciences, Wuxi, 214081, China
4 East China Sea Fishery Research Institute, Chinese Academy of Fishery Sciences, Shanghai, 200090, China DOI : 10.4194/1303-2712-v17_6_22 Viewed : 3512 - Downloaded : 2680 Gillnet selectivity on the small yellow croaker, Larimichthys polyactis, was investigated in the southern Yellow Sea. Ten gillnet series were tested: two net heights (6 and 10 m) and five mesh sizes (35, 40, 45, 50, and 55 mm). The age 0+ and 1+ groups dominated the catch with proportions of 43% and 53%, respectively. The sex ratio was found to be size- and agedependent in gillnet surveys, with males increasingly dominant in the smaller size and younger age classes. Nets with heights of 10 m caught selectively more age 0+ individuals and males than 6 m height nets. Gillnet selectivity estimates derived from girth frequency distribution were represented by a binormal model, and the optimal mesh size for 50% retention for the proposed minimum landing size (body length 148.3 mm) of L. polyactis was estimated as 45 mm. We suggest that a gillnet with a mesh size of 45 mm and net height of 6 m is optimal for exploiting L. polyactis as it is less selective for juveniles and smaller males. Keywords : Larimichthys polyactis, gillnet, selectivity, age structure, sex ratio, southern yellow sea