长江口及邻近海域高营养层次生物群落功能群及其变化

Functional groups of high trophic level communities in adjacent waters of Changjiang estuary

通过对2006年6、8和10月在长江口及邻近海域3次调查采集样品的分析,对该水域的高营养层次生物群落的功能群组成及其变化进行了研究.结果表明:长江口及邻近海域高营养层次生物群落包括鱼食性、蟹食性、虾食性、底栖动物食性、浮游生物食性和广食性6个功能群.由于受海洋环境变化以及鱼类洄游活动的影响,各月份长江口及邻近海域高营养层次生物群落的组成及营养级都有较大的变化.6月高营养层次以鱼类、毛虾类和蟹类为主,以浮游生物食性功能群为主要功能群,营养级最低,为3.06;8月高营养层次以鱼类为主,虾食性功能群为主要功能群,营养级达到最高,为3.78;10月高营养层次虽仍以鱼类为主,虾蟹类比例增大,功能群以浮游动物食性和底栖动物食性功能群为主,营养级为3.58.

Based on the three bottom trawl surveys in adjacent waters of Changjiang estuary in June, August and October 2006, the composition and variation of the functional groups of high trophic level communities in the waters were studied. According to diet analysis, the high trophie level communities in the waters included six functional groups, i. e. , piscivore, shrimp predator, crab predator, benthivore, planktivore, and generalist predator. Due to the variation of marine environment and fish migration behavior, the composition and trophic level of the high trophie level communities had greater monthly change. In June, fishes, acetes, and crabs dominated the communities, and planktivore was the major functional group, with its trophic level being the lowest （3.06） ; in August, fishes were dominant, and shrimp predator was the major functional group, with its trophic level being the highest （3.78） ; and in October, fishes also dominated the eommunities, the proportion of shrimp and crab increased , and planktivore and benthivore were the major functional groups, with a trophic level of 3.58.