한반도 서남부 하천 하구역의 수질 및 부착돌말 군집 특성

Abstract

Environmental factors and epilithic diatom communities in the lower streams near the harbor regionof South Korean peninsula were examined during no monsoon period in May 2013. The sampling of water andepilithic diatoms was conducted at both streams, 19 regulated streams(RS) that there are one or several damsconstructedin the river system, and 19 un-regulated streams(US) that there are no dams within the river. Acluster analysis based on the number of species and abundance of epilithic diatoms through the stations, dividedinto three groupssuch as groups I(mainly US), II(mixed with US and RS) and III(mainly RS), respectively.Group I showed that water quality is good and high diversity of diatom, while Group II and III was waterquality is relatively poor, but not differed in biomass of diatom from Group I. In addition, Group II that had highconductivity, nitrogen and phosphorus, was the lowest in diatom diversity among them. Dominant specieswere Nitzschia palea(17%) and Navicula seminuloides(11%) in Group I, Nitzschia inconspicua(19%) andNavicula perminuta(9%) in Group II, and Nitzschia inconspicua(15%) and Nitzschia palea(14%) in GroupIII, respectively. These taxa were widely distributed in brackish water, and not closely related with specificwater quality, like eutrophic water. However, the groups II and III belonged to RS, had not only little biomass,but bad water quality such as high concentrations of nutrient and chlorophyll-a. Therefore, to determine theeffect of dam construction on the lower water ecosystem, the planktonic algae, which can occur algal bloom inthe estuary, also was considered to be a parallel investigation.