Temporal variation of macrobenthic community zonation over nearly 60 years and the effects of latitude and depth in the southern Yellow Sea and East China Sea

摘要

To examine the temporal variation of macrobenthic community zonation over nearly 60 years and the effects of latitude and depth in the southern Yellow Sea and East China Sea, a total of 1386 box-corer samples from four large spatial scale studies during 1958-1959, 2000-2004, 2011-2013 and 2014-2016 period, respectively, were compiled. A total of 26,14,13 and 18 communities were identified, respectively during the four periods with the same analytical method. The Yellow Sea Cold Water Mass (YSCWM) community, restricted to the 34°N latitude in the south and 50 m isobaths in the west, varied little in its spatial pattern over nearly 60 years, while other communities did not. The representative species in the YSCWM community changed from the polychaetes to the brittle stars during 1958-2016. However, in other large spatial scale communities except the YSCWM community, the representative species changed from the echinoderms, nemerteans or crustaceans to the polychaetes. For the revisited locations across studies, significant temporal and spatial variations in community structure at both species and family levels were detected. Macrobenthic species with high consecutive contributions to the community similarity were significantly influenced by latitude, depth, temperature and salinity, among which latitude and depth were the first two most significant environmental variables. Species diversity increased from 32 to 37°N during 1958-1959, but decreased during 2014-2016. It seems that the latitude of 32°N is an ecological barrier for macrobenthic community and diversity, but its effects weakened from 1958 to 2016. Species diversity roughly showed a first increasing then decreasing trend with the increase of the water depth in the southern Yellow Sea and East China Sea.