应用浮游植物监测与评价长江口水体营养状况

Monitoring and assessment of water trophic states using phytoplankton community in Changjiang Estuary

通过对长江河口浮游植物采样研究，应用浮游植物群落多样性指数和均匀度指数、浮游植物丰度以及生物学综合评价法对长江河口水体营养状况进行监测与评价。生物学综合评价结果显示：1999年枯水期，口门内的SX01～SX04样站表、底层水体为中营养水平，口门外近岸及近外海水域一般为贫营养水体。1999年丰水期，表、底层水质状况与枯水期不同，口门内的SX01～SX04样站水体为贫营养型，近口门、近外海水域为中营养型，近岸中部、东部表层一般达到富营养型水体，近岸底层东北部为富营养型，其余近岸水域为中营养型水体。2000年枯水期水质情况为：口门内表、底层水体为贫营养水体，近岸水域表层为中营养水体，底层为贫营养水体，近外海水域表、底层一般也为贫营养水体。

Based on the samples collected from the Changjiang Estuary, monitoring and assessment of water nutrient states have been made through the methods including diversity index, evenness index, abundance and bioassessment of phytoplankton community. The results by means of the standard of bioassessment of phytoplankton community showed that in the dry period of 1999, the surface and bottom layers of water of stations SX01～SX04 inside the river mouth were a mesotrophic type; and the waters nearshore and offshore outside the river mouth were generally an oligotrophic type. In the wet periods of 1999, the condition of water quality was different from that of water during the dry periods. The waters of stations SX01～SX04 inside the river mouth were an oligotrophic type. The waters near the river mouth and offshore were a mesotrophic type, and the surface layers in the mid-east nearshore generally reached the level of the mesotrophic type; bottom layer in the northeast nearshore was also an eutrophic type; the rest were a mesotrophic type. Such are the water quality conditions in the dry period of 2000. And the surface layers of waters nearshore were a mesotrophic type and the rest were an oligotrophic type.