底生動物の炭素・窒素安定同位体比を用いた中国地方一級河川の環境評価

抄録

 In this study, a new assessment of river environment using benthic fauna is proposed. Field observations for the samplings of water quality and benthic fauna were conducted at 5~12 points in the ten first-class rivers of Chugoku district. As a result, there wasn't any significant correlation relationship among the water quality (T-N) and the stable isotope ratios of nitrogen (δ¹⁵ N) in benthic fauna. However, δ¹⁵ N in benthic fauna have a clear relation with the land use ratio of urban and farm area in the catchment for each sampling point which was estimated using GIS analysis. This result indicates that the δ¹⁵ N in benthic fauna can be an indicator of the river environment.