Changes in macrobenthic community structure and benthic environmental characteristics in Songdo Tidal Flat on the west coast of Korea

초록

This study was conducted to assess the current status of marine benthic communities in Songdo Tidal Flat of Incheon, Korea. This site was designated as a marine protected area in 2009 to protect the feeding grounds for birds (black-faced spoonbill, Platalea minor) from reclamation activities. We sampled the macrobenthos in 2013 in the same area in which a benthic community survey was conducted in 1995–1997. The surface sediment was finer than in 1995–1997 and the mean density and biomass of macrobenthos were significantly increased, but average diversity index was decreased. In previous studies, the bivalve Mactra veneriformis occurred as a biomass dominant fauna, but they did not appear in this study. Instead, the bivalve Potamocorbula laevis, which is known as a brackish water species, appeared to be the new biomass dominant species. Polychaete indicating species of organic pollution such as Heteromastus filiformis and Mediomastus californiensis have been ranked as dominant species, and their density was higher than in the previous study. Multivariate analyses enabled the whole macrobenthic community to be distinguished into two groups of past (1995–1997) and present (2013). Overall, these findings indicate that shoreline modification due to reclamation activities may have negative effects on the macrobenthic community structures and dominant species composition in Songdo Tidal Flat.