In the Yellow Sea of China, large scale green tides have broken out for four consecutive years from 2007 to 2010. The main causative species of green alga was identified as Ulva prolifera. The original source of this seaweed was suspected to be from the south of the Yellow Sea (Jiangsu open-sea) as revealed by satellite images. The floating biomass drifted with water current northward and flourished in nearshore waters around Qingdao, some reports showed that the Porphyra cultivation areas and aquaculture p...