한국 서해안 이원 갯벌에 조성된 인공 퇴적 촉진 구조물로 인한 중형저서생물 군집의 변동 및 이동

Abstract

During the last decade, meiobenthos have been examined as an indicator to assess environmental condition of marine benthic ecosystem because comparatively short generation time causes rapid response of the populations to variable environments. Detailed information of environmental factors and successions of representative benthos is required because the function of the tidal flat is sustained by variable environmental conditions and activities of many marine organisms. For that reason, It is necessary to continuous post monitoring of macro- and meio- benthos in the artificially constructed or promoted tidal flat. The study was conducted on the sandflat near the Iwon dike located in west coast of Korea. Samples of meiobenthos were collected seasonally from 2002 to 2005. In total, 10 sampling stations near the deposition-promotional facility were included in the study. A total of 12 meiofaunal groups were found in the study area in Iwon. Nematodes were the most dominant among the meiofaunal groups as a whole. Benthic foraminiferans, harpacticoid copepods, polychaetes and nauplius of crustacean were also dominant groups in all site. The total density of meiobenthos at each stations was 246 ~ 2,177 ind./10㎠ in the tidal flat of the study area in Iwon. As the sediment depth increase, the density of meiobenthos in each station decrease gradually. The major change of meifaunal density in the study area were mainly occur in sediment surface (0~1cm). Generally, the density of nematodes was increased, and the density of another dominant meiofaunal group (benthic harpacticoids, nauplius of crustacean, benthic foraminiferans etc.) was decreased near the sediment trap against the control site of sediment trap during the period of spring to summer. Based on the results of cluster and MDS plots, meiofaunal community was changed by construction of artificial low-crested wood groin facility. A total of 14 major meiofaunal taxa, including copepoda nauplius, were recorded in the sedi