Lessons from the Korean Shihwa dike construction in the Japanese Isahaya dike construction

초록

Effects of the Korean Shihwa dike construction was studied on the benthic communities inside and outside Shihwa dike. It is suggested that sequential changes in macrofaunal assemblages progressed in two successional directions in the Shihwa lake under the influence of organic enrichment, the appearance of 'azoic zone' or 'grossly polluted zone' developed in teh area of less than 6m in depthresulted from the severe DO depletion due to the eutrophication from the increased organic loading and 'polluted zone'characterized by the proliferation of the opportunistic species in organically enriched area in the vicinity of the industrial discharges and nearby fluvial inputs. However, these phenomena were improved by openning the water gate of the dike, and the benthic species richness incresed after 2.5 years of openning the gate. But, species composition changed remarkably due to the different oceanographic conditions inside the Shihwa lake.