Community Structure and Health Assessment of Macrobenthic Assemblages at Spring and Summer in Cheonsu Bay, West Coast of Korea

This study was performed to investigate the community structure and health assessment of macrobenthic assemblages in Cheonsu Bay, West Coast of Korea. Total species number was 224 and mean density was 1,940 ind./m 2 , both of which were dominated by polychaete worms (111 species and 1,213 ind./m 2 ). In terms of density, the major dominant species were the bivalve Theora fragilis (280±213 ind./m 2 ), the polychaetes Heteromastus filiformis (254±218 ind./m 2 ), Lumbrineris longifolia (216±41 ind./m 2 ), Mediomastus californiensis (158±97 ind./m 2 ) and the amphipod Eriopisella sechellensis (167±100 ind./m 2 ). As a result of community statistics (cluster analysis and nMDS ordination), the macrobenthic community structure was classified two major groups (inner and mouth of bay) and two stations (station 2 near Ganwol dyke in spring and summer). The Benthic Pollution Index (BPI) and AZTI's Marine Biotic Index (AMBI) were applied to assess the benthic ecological status. During the sampling periods, the BPI Index values varied between 11 (bad status) and 92 (high status). On the other hand, the AMBI Index values was ranged between 1.34 (good status) and 4.39 (poor sta