Community Structure and Health Assessment of Macrobenthos in the Geum River Estuary, Korea

The purpose of this study was to identify the community structure and health index of Macrobenthos in the Geum River Estuary, evaluate the benthic ecosystem, and use it as basic data for developing efficient management plan. Sediment, Salinity and macrobenthos samples were collected four times (season) at 15 stations, 2018 . As a result, the sand content and salinity tended to decrease from the Geum River Estuary entrance area (brackish) to tne outer sea area (ocean). A total of 226 species/12㎡ occurred with mean density of 932 ind./㎡, mainly composed of Annelids, Arthropods and Mollusks. Based on the density, there were 13 dominant species accounting for approximately 48.3% of total individuals. Cluster analysis and nMDS ordination analysis based on the Bray-Curtis similarity divided into 3 groups. The entrance area (brackish) was A group, the middle area (disturbed) was B group, the outer sea area (ocean) was C group. As a result of analyzing three health indices, the entrance area was found to be in relatively slightly polluted condition. The macrobenthos community showed a station group clearly divided into the entrance and outer area, which is believed to be due to environmental factors such as salinity concentration and sedimentary facies.