An overview of studies on marine macrobenthic biodiversity from Chinese waters: principally from the Yellow Sea

The progress on the studies of marine macrobenthic biodiversity from Chinese waters with a focus on the Yellow Sea is summarized in the present paper, with discussions of achievements in the fields of species composition, individual consistency, biomass, biodiversity, secondary productivity, macrobenthic community energy levels, and the introductions of research methods, impacts of environmental change and pollution. To date, Jiaozhou Bay, Changjiang Estuary, and the Fujian and Zhejiang coastal zones are the most intensively studied regions. The seminal research projects on macrobenthic ecology and biodiversity within the study region are also listed. In conclusion of the studies of macrobenthic ecology and biodiversity in China seas, the macrobenthic fauna from the Bohai Bay is the most simple. A total of 413 macrobenthic species have been found in this gulf, the common or dominant species are usually the hypothermal, euryhalinous warm water species; the annual mean biomass is 19.83 g/m2, the Mollusca is the main contributing group to the biomass; the annual mean density is 474 inds./m2, the Polychaeta and Mollusca are the two main contributing groups to the density. In the Yellow Sea, 853 macrobenthic species have been found. The common or dominant species are stenohaline warm water species; the annual mean biomass from the northern Yellow Sea is 99.66 g/m2, the Echinodermata is the main contributing group to the biomass, the annual mean biomass from the southern Yellow Sea is 27.69 g/m2, which is much lower than that from the northern Yellow Sea, the Polychaeta is the main contributor; the annual mean density from the northern Yellow Sea is 2,017.40 inds./m2, that from the southern Yellow Sea is only 88.67 inds./m2. In fact, the mean density and biomass from the northern Yellow Sea is much higher than those from other areas in China seas; the annual mean secondary productivity from the southern Yellow Sea is 4.98 g(AFDW)/m2, the two high areas of secondary productivity are located in the two sides of the Yellow Sea Cold Water Mass. In the East China Sea, there have been found 1,300 macrobenthic species, in which, 45 are common or dominant ones; the differences among the seasonal mean biomasses are indistinct, usually spring>winter>summer>autumn; the annual mean biomasses from area off Zhejiang Province(28.22 g/m2)>Changjiang Estuary area (15.55 g/m2) >Taiwan Strait (8.98 g/m2), the annual mean density from the East China Sea is 164 inds./m2, the trend of the density is higher and higher from north to south areas. In the South China Sea, 1,661 macrobenthic species, distinctly more than those from the Bohai Gulf, Yellow Sea and East China Sea, part of dominant species are the same as those from the East China Sea, very different from those from the Bohai Gulf and the Yellow Sea; the annual mean biomass is 20.06 g/m2, usually the seasonal biomasses are spring>winter>autumn>summer, the Mollusca and Echinodermata are the two main contributing groups to the biomass; the annual mean density is 198 ind./m2, usually the seasonal densities are summer>spring>winter>autumn, the Polychaeta is the main contributor to the density. The main themes of this research are ever-increasing impacts from human activities and global climate change, and the pressing need for conservation of marine biological resources. The conservation and sustained utilization of marine biological resources need the understanding of the changing mechanisms of marine macrobenthic biodiversity based on the approach of long-term change of marine environment.