杭州湾北岸表层水域浮游动物种类组成及季节变化

The composition and seasonal changes of surface zooplankton in the north shore of Hangzhou Bay

为了探讨杭州湾北岸表层水域浮游动物的群落结构季节性变化以及与环境因子的相关性,2014年8月（夏季）、11月（秋季）和2015年2月（冬季）、5月（春季）,在杭州湾北岸水域（121°45＇-122°09＇E,30°45＇-30°51＇N）设置10个站点,每月大潮期间,以大型仔稚鱼网（口径130 cm,网目0.5 mm）进行表层拖网。结果表明,4航次采集到浮游动物12类42种,其中优势种共10种,秋季优势种最多（7种）,夏季最少（4种）。四季共有优势种为真刺唇角水蚤（Labidocera euchaeta）、火腿伪镖水蚤（Pseudodiaptomus poplesia）、虫肢歪水蚤（Tortanus vermiculus）3种。平均生物量和丰度在夏季达到最大（120.17 mg/m^3,1 290.53 ind./m^3）,冬季最小（14.21 mg/m^3,67.03 ind./m^3）。该水域浮游动物可分为4种生态类群：淡水类群、河口类群、近岸低盐类群和广盐类群。与环境因子的SPSS双变量相关性分析得出,浮游动物群落结构与温度、盐度、溶解氧和叶绿素a有明显关系,其中温度和盐度是影响浮游动物群落结构的关键因子。

To clarify the community structure and seasonal changes of surface zooplankton in the north shore of Hangzhou Bay,as well as the relationship with environmental factors,zooplankton were collected at 10 stations in the north area（ 121°45＇-122°09＇E,30°45＇-30°51＇N） by a larvae net（ 130 cm mouth-diameter,0.5 mm mesh-aperture） during the spring tide each month in August and November 2014,February and May2015.In this research,a total of 42 species were collected,of which 10 were dominant species.7 dominant species were identified in Autumn（ the most） and 4 dominant species were identified in summer（ the least）.However,only Labidocera euchaeta,Pseudodiaptomus poplesia and Tortanus vermiculus were the common dominant species in four seasons.The highest mean biomass and abundance of zooplankton were in summer and the lowest were in winter.The results indicated the zooplankton in the north shore of Hangzhou Bay could be divided into four ecotypes： freshwater group,estuarine group,inshore low salinity group and eurytopic group.The analysis from SPSS showed that the seasonal changes of zooplankton community were obviously affected by salinity,water temperature,Chl.a and DO.However,water temperature and salinity were the two key factors for community structure.