东海近岸海域浮游动物群落时空分布

Analysis of the temporal and spatial variations of zooplankton community in coastal East China Sea

为探讨东海近岸海域浮游动物时空分布特征,根据2013年5月(春季)、8月(夏季)和12月(冬季)东海近岸海域3个航次的浮游动物调查资料,分析了该海域春季、夏季和冬季浮游动物的种类组成、丰度与生物量、优势种季节变化及生态类群。结果显示,3个航次共鉴定浮游动物108种(含未定种),浮游幼体14类,隶属于7门15大类,其中桡足类和水母类的种类和数量占绝对优势,桡足类为最优势类群,共47种,占总种数的43.52%,水母类共19种,占总种数的17.59%。浮游动物种类季节变化较为明显,夏季种类显著高于春季和冬季。各季节浮游动物种类数目与纬度呈负相关。浮游动物平均丰度与平均生物量随季节变化较为明显,其中平均丰度与平均生物量冬季最低,平均生物量夏季最高,平均丰度春季最高。根据浮游动物对水文环境条件耐受性和生活海区的差异性将浮游动物群落分为6个生态类群:近岸低盐种、广温广盐种、高温高盐种、近岸暖温种、暖水种和大洋广布种。其中东海北部近岸海域春、冬季近岸低盐种和广温广盐种占绝对优势,夏季暖水性种群所占比例高;长江口及邻近水域暖水性种群在春、夏、冬三季中均占主导地位;东海中南部近岸海域春、冬季暖水性种群占绝对优势,但夏季高温高盐种、大洋广布种优势明显。各季节中华哲水蚤均为优势种,但其他优势种季节更替较明显,其中春、夏两季优势种更替率为90.9%,夏、秋两季为50%。

In order to discuss the temporal and spatial variations of zooplankton community in coastal East China Sea and based on the data obtained from 3 cruises of zooplankton surveys conducted in the coastal waters of East China Sea in May, August and December of 2013, the species composition, biomass and abundance, dominant species and ecological groups were investigated. The results showed that a total of 108 species belonged to 15 groups in 7 phyla, including undefined species, together with 14 classes of pelagic larvae. The 7 phyla including Cnidaria,Ctenophora, Annelina, Mollusca, Arthropoda, Chaetognatha and Urochordata. Copepoda and Medusae were the most dominant groups in numbers of species and abundance. The most dominant group of zooplankton was Copepoda, including 47 species accounting for 43.52%. Medusae ranks second with a total of 19 species, accounting for17.59%. There was a considerable seasonal variation in species of zooplankton in the coastal waters of East China Sea. In summer, the species richness was significantly higher than spring and winter. The linear relationship of species and latitude was negative correlated in May, August and December, which reached an extremely significant level. The whole area average abundance and biomass of zooplankton of coastal waters in East China Sea changed seasonally. Both the average abundance and biomass in winter were the lowest, the average biomass was the highest in summer, and the average abundance was the highest in spring. The community can be divided into 6 ecological groups according to the tolerance of zooplankton in hydrological environment and the differences of living areas, which were coastal species of low salinity, wide temperature and salinity species, high temperature and salinity species, warm coastal species, warm water species and cosmopolitan species. In spring and winter the coastal species of low salinity, wide temperature and salinity species accounted for absolute advantage in the southern Yellow Sea coastal waters, but warm water species were in higher proportion in summer. However, in Yangtze River estuary and adjacent waters, the warm water species were the dominant community in spring, summer and winter. What＇s more, in the central and southern coastal waters, warm water species play a dominant role in spring and winter. But the high temperature and salinity species, cosmopolitan species community was obviously dominant in summer. Calanus sinicus was the only common dominant species in these seasons. Dominant species changed more obviously, and the dominant species turnover rate was 90.9% from spring to summer, which was 50% from summer to autumn.