胶州湾网采浮游植物群落结构的长期变化

Based on survey data collected using plankton net from the 1980＇s in the Jiaozhou bay,long-term changes of the phytoplankton community were analyzed in this study.The results indicated that total abundance of phytoplankton started increasing since 1981,and the increase was evident since 2000,especially in winter.However,there were no distinct changes in the spatial distribution patterns.The dominant phytoplankton species also changed in recent years.Some phytoplankton species,including Guinardia striata,Rhizosolenia alata f.Indica,and Hemiaulus sinensis,which were once dominant before the 1990＇s,lost their dominance after 2000.The new dominant species,including Chaetoceros lorenzianus,Chaetoceros densus,Lithodesmium undulatus,Ceratium furca,and Ceratium fusus,appeared in the past five years.The long-term changes of the dominant species revealed that the small chained diatoms such as Skeletonema costatum and Chaetoceros sp.,the warm water species such as Lithodesmium undulatus,and the dinoflagellates such as Ceratium furca and Ceratium fusus,increased dramatically in the past 30 years,indicating that the phytoplankton community had changed in response to the impacts of climate change and human activities in the Jiaozhou Bay.