Impact of the coastal urbanization on the subtidal macrobenthic communities in Gyeonggi Bay, Korea

초록

Coastal urbanization is a major cause of loss of marine biodiversity. It exerts also significant influences on the structure and function of coastal habitats, mainly through modifying the hydrological and sedimentation regimes, and the dynamics of nutrients and chemical pollutants. Indeed, during the last two decades, Gyeonggi Bay area has been suffering from the intensive pressures of anthropogenic driving forces, including various constructions of the dike construction and subsequent tidal power plant, Incheon International Airport and tidal flat reclamation for Songdo New City planning. Little is known about the impact of habitat degradation on subtidal shallow-water habitats and therefore this study was focused on the changes in the macrobenthic assemblages due to these diverse environmental disturbances. Fifty-one stations were located in the shallow-water subtidal waters in Gyeonggi Bay, Korea, and sampled in August 2014 for macrofauna, water and sedimentary parameters. Overall, the macrobenthic assemblages were characterized by a total of 305 species number, mean abundance of 826 ind/㎡, and 86g WWt/㎡. The polychaetes were most dominant group: Heteromastus filiformis, Sternaspis scutata, Lumbrineris longifolia and Mediomasts californiensis together with a mytilid bivalve Arcuatula senhousia. The multivariate techniques revealed that the shallow-water macrobenthic fauna in community structure and composition were divided into 5 different groups as follows; (1) Capitella-dominated heavily polluted area (Innermost areas of Incheon North port ), (2) the upper stream Sihwa Lake dominated by Arcuatula senhousia and some polychaetes, (3) areas around outlet of the Ansan city sewage treatment plant and middle part in North Port; (4) shipping channels for the Incheon Port, (5) the other areas.