Studies On Ecology And Biomass Size Spectra Of Zoobenthos On Lingchuan Shellfish-farming Mudflat, Meizhou Bay

Shellfish farming is an important industry in China. However, as the aquaculture developped, the environment of mudflat became worse and worse and bio-pathogeny grew up, many species of shellfish dead cosmically which retarded the aquiculture industry. Studies on benthic ecology and biomass size spectra on shellfish farming mudflat may help to evaluate the ecosystem of mudflat, provide evidence for appropriate aquiculture capacity and evaluating environmental quality. We investigated benthic status on Lingchuan shellfish farming mudflat of Meizhou Bay, which was the important aquiculture base of Ruditapes philippinarum in Fujian. New statistic software has been used to analyze macrofaunal community structure. Meifauna and biomass size spectra of benthos constructed on shellfish farming mudflat were studied firstly. The results as following:1. During four surveys from June 2005 to March 2006, 101 species of macrofauna were identified, including 52 Annelida, accounting for 51.49 percent to total number; 25 Mollusca, accounting for 24.75 percent; 18 Crustacea, accounting for 17.82 percent; 3 Chordata, accounting for 2.97 percent; Coelenterata, Platyhelminthes and Echinodermata,1 specie each, each occupied 0.99 percent respectively. Mean density was 2084 ind·m-2, mean biomass was 152.32 g·m-2,mean secondary production was 21.23 gAFDW·m-2·yr. There was significant difference in March compared with other seasons.2. Mean density of meiofauna was 657 ind·10cm-2, nematode and copepod were the main groups. Nematode accounts 97.3 percent to total meiofaunal density while copepod accounts 1.2 percent. Mean biomass of meiofauna was 0.357 gdwt·m-2, as 1.3 percent of macrofaunal, while secondary production was 13.6 percent of macrofaunal. There also displayed a significant difference between spring (March) and other seasons of meiofaunal density and biomass as macrofauna.3. Based on zoobenthic density and biomass in four seasons and six sampling stations, two types of biomass size spectra were constructed. The shape of biomass size spectra was partly irregularly serrated, at 4-8 size level across a logarithmic scale of body mass, there was an obvious trough, showed that biomass size spectra of benthos is conservative. The slope of normalized biomass size spectra was higher...