Abstract

By the species composition of macrobenthic community on the tidal flat of Garolim Bay, study area was divided into two regions, located near mouth and inner part of bay. Two regions were named as TFMB (tidal flat in the vicinity of the mouth of bay) composed of Ojiri (OGA, OGB), Mandae (MD) and Gopa (GP), and TFIB (tidal flat of inner bay) composed of Youngtap (YT), Heuksuk (HS), Duksong (DS) and Changsun (CS). Species number, density and biomass of macrobenthos in TFMB were higher than in TFIB., Dominant species in TFMB were Heteromastus filiformis and Mediomastus sp. belonging to polychaetes, and besides that, Musculus senhousia and Ruditapes philippinarum as a member of bivalves were seasonally important species. However, dominant species in TFIB were Macrophthalmus japonicus, Ilyoplax pingi and some amphipod species belonging to crustaceans. Main species in TFMB were composed of species known to inhabit on mixed tidal flat, but those in TFIB were on mud flat. As a result of PCA, there were high correlations with occurring species and their specific environments. M. japonicus, I. pingi and C. sinense showed high positive relations with fine sedimentary environments (mean grain size, organic matter content, sorting and AVS etc.) being typically characteristics of mud flat of inner Garolim Bay. H. filiformis, Mediomastus sp., Nephtys polybranchia, Armandia lanceolata, M. senhousia and R. philippinarum were closely related with coarse sedimentary environments and ecological parameters of macrobenthic community (density, biomass, diversity index and richness index etc.) being typically characteristics of mixed flat of mouth of Garolim Bay.