Study On Ecological Functions Of Macrobenthos In Yantai Sishili Bay

Macrobenthos is an important ecological groups,which plays an important role in energy flow and material cycling of marine ecosystem.In this papermacrobenthos samples were collected in spring(May)2009 and autumn (October) 2009 in Yantai Sishili Bay.The spatial and temporal variation of macrobenthic community structure in Sishili Bay were firstly stuied in this paper. Furthermore, the ecological production was calculated with empirical formula of Brey (1990). And the sea water quality was assessed by macrobenthic diversity indices (H'), richness index (D) and pollution index (MPI). The main results are as follows:1. A total of 92 species of macrobenthic were identified in Yantai Sishili Bay, including Annelida (52 species), Mollusca (23 species), Arthropoda (10 species), Echinodermata (3 species), Nemertea (1 species), Urochordata (1 species), Coelenterata (1 species), and Phylum Sipunculida (1). The number of macrobenthos species in offshore waters was higher than that in inshore waters, and the species number in autumn was higher than that in spring.2. There were six dominant species, including Annelida (3 species), Mollusca (2 species), and Urochordata (1 species). Lumbrineris latreilli and Notomastus sp. were the common dominant species in spring and autumn, and Lumbrineris latreilli was absolute dominant species in Yantai Sishili Bay.3. The average abundance of macrobenthos was 1939.4 ind/m2. The abundance in spring and autumn was 1494.7 ind/m2 and 2384.0 ind/m2 respectively. Annelids was the most abundance macrobenthic.The average biomass (wet weight) of macrobenthos was 50.62 g/m2.The biomass in spring and autumn was 24.48 g/m2 and 76.76 g/m2, respectively. Annelids was the biomass-dominant groups in spring, and Urochordata was the biomass-dominant groups in autumn as inffluednced by the large biomass of Styela clava. The abundance and biomass of macrobenthos in autumn was higher than that in spring and the abundance and biomass in inshore waters was higher than that in offshore waters.4. Average ecological production was 8.911 g(AFDW)/(m2·a) in Yantai Sishili Bay. Annual productivity was 1158.43 t, and P/B ratio was 0.98. There were a total of 13 species of macrobenthos, whose ecological production contributed to more than 1% of total annual productivity, including Annelida (6 species), Mollusca (5 species), Echinodermata (1 species), and Urochordata (1 species).5. Water quality in Yantai Sishili Bay was light pollution-light pollution by H 'comprehensive evaluation, was light - moderate pollution by D comprehensive evaluation, and was clean-light pollution by MPI evaluation. The offshore water quality was better than inshore water, and the water quality in spring was better than that in autumn.