Dynamic characteristics of abundance and community structure of fishery species in the overwintering ground of the Bohai Sea
渤海赵冬场渔业生物资源量和群落结构的动态特征

By the bottom trawl surveys in the overwintering ground of the Bohai Sea in the winter of 1983,1993 and 1999,the yearly variations of species composition,abundance index and dominant species of endemic stocks were analyzed The abundance trended to decrease dramatically,the average catch per haul was 11 5,3 5 and 0 7 kg/h,and average number of individuals per haul was 669,145 and 37 individual/h,respectively The community structure and dominant species obviously changed Those dominant species like Collichthys spp.and Raja porosa in 1983～ 1993 were replaced by Neosalanx anderssoni in 1999 Overfishing is the main cause for the sharp decrease of abundance in economic important species Strengthening fishery management,and implementing hatchery release are the main measures and approaches to conserving,rehabilitating and enhancing fishery resources in the Bohai Sea