Abstract
Temporal changes in the growth of the filamentous green algae belonging to the gunus Cladophora and the effects of algal growth on environmental conditions and the clam Corbicula japonica were studied from June 2016 to July 2017 in Lake Shinji nearshore waters. Cladophora spp. started to grow around June and disappeared by December. In a year, there were two peaks in coverage. Low dissolved oxygen concentration, reduce sediment condition, and low frequency of Corbicula japonica were observed under Cladophora spp. mats in summer. In particular, low oxidation-reduction potential (ORP) (-334 mV), high sulfide ion concentration, and no survival of C. japonica were recorded after Typhoon No. 16 in 2016. It was suggested that Cladophora spp. mats in the lacustirine nearshore environments cause environmental deterioration of lake water and substrate, and have lethal effects on C. japonica.
