Phytoplankton And Trophic Status Of Three Reservoirs In Fujian Province, China

Reservoirs are responsible for drinking water resource in Fujian, and play important roles in human livelihood, In the present study, it is the first time to annually investigate and compare the changes of phytoplankton and the environmental factors in three reservoirs of Fujian, Bantou reservoir, Tingxi reservoir, Shanzai reservoir in 2010. Moreover, the results about phytoplankton in three reservoirs are also compared with a shallow lake, Lake Chaohu, to explain by which phytoplankton changes and responses to eutrophication processes of reservoirs and lakes. The results will provide important information for the study on the ecology of phytoplankton.In this study, about 127 phytoplankton species belonging to 74 genera,8 phylum, 120 phytoplankton species belonging to 70 genera,7 phylum, and 48 phytoplankton species belonging to 33 genera,6 phylum were found in Bantou reservoir, Tingxi reservoir, and Shanzai reservoir, respectively. The mainly dominant species are, Cylindrospermopsis raciborskii in Bantou Reservoir, Pseudanabaena catenata and Aphanizomenon issatschenkoi in Tingxi Reservoir, Anabaena kisseleviana, Microcystis aeruginosa and Pseudanabaena mucicola in Shanzai Reservoir. The average density of phytoplankton in three reservoirs was 307.99×106 cell/L,19.61×106 cell/L,84.58×106 cell/L, respectively.About 163 phytoplankton species belonging to 82 genera,7 Phylum were found in Chaohu. The dominant species were Anabaena flos-aquae, Aphanizomenon fios -aquae, Microcystis aeruginosa, Microcystis Wyeth, Microcystis viridis, and Pseudanabaena mucicola, Planctonema lauterbornii, Cyclotella meneghiniana, community structure was complex. The annual average algae density was 129.2×106cell /L.Comprehensive analysis of the three index, Shannon Weaver diversity index,Pielou evenness index and Abundance index, the degree of eutrophication in three reservoirs is Bantou> Shanzai> Ting Xi. Apart from Shanzai reservoir, dominant species in three reservoirs have shorter period of time eand outbreak of a lower level. The community structure in Chaohu is more complex, the dominant Cyanobacteria are more frequent and in the high wide distribution. Analysis of annual changes in water quality factors in three reservoirs in Fujian Province, combined with RDA and CCA in the software canoco4.5 for further analysis of environmental factors and the relationship between species. In Bantou Reservoir COD shows most relevant with Cylindrospermopsis raciborskii. In Tingxi River, the succession Pseudanabaena catenata and Aphanizomenon issatschenkoi may be correlated with changes in total nitrogen, Aphanizomenon issatschenkoi shows more correlation with temperature. Anabaena kisseleviana in Shanzai Reservoir is correlation with dissolved oxygen, followed by the TP. Microcystis aeruginosa shows correlation with temperature and Pseudanabaena mucicola most correlated with N/P and the SD.Research shows that Pseudanabaena mucicola in Shanzai Reservoir and Chaohu Lake have significant correlation with Microcystis, with Microcystis aeruginosa and Microcystis Wyeth related to the maximum. Anabaena flos-aquae in Chaohu has become the dominant species distributed throughout the year.