兴化湾浮游动物群落季节变化和水平分布

兴化湾为福建北部最大的海湾,于2006年对该海湾浮游动物群落进行了四季9个站位的调查。共检出浮游动物及幼虫124种,其中春季42种,夏季89种,秋季71种,冬季20种;分属近岸暖温、近岸暖水和广布外海3个生态类群;优势种15种,春季以水母和桡足类占优势,夏季以水母占优势,秋季以水母、桡足类和箭虫占优势,冬季则以桡足类占优势。不同季节兴化湾浮游动物生物量湿重和丰度水平分布特征变化明显,并与温度和盐度呈显著相关。聚类分析显示兴化湾浮游动物群落夏季类群和秋季类群相似度较高;各季节水平分布基本可分为湾口区和湾内区两大类群。与20世纪80年代相比,尽管本次调查浮游动物群落没有表现出显著差异,但随着电厂等大规模工程的投产,兴化湾海域生态系统健康面临着极大威胁,其环境压力需引起持续关注。

Seasonal variation and horizontal distribution of zooplankton community in Xinghuawan Bay

Xinghuawan Bay is the biggest bay in northern Fujian Province of China. A comprehensive investigation on the population of zooplankton was conducted at 9 stations seasonally in 2006. Total 124 zooplankton species with 10 larvae were identified during the investigation. Among which 42, 89, 71, and 20 species occurred in spring, summer, autumn, and winter, respectively. All these zooplankton could be divided into three ecotypes, including offshore warm-water group, offshore warm-temperature group and eurytopic group. There were 15 dominant species during sampling period. Among which jellyfish dominated the community in spring, summer and autumn, copepods dominated in spring, autumn and winter, chaetognatha dominated in autumn. Seasonal variations of horizontal distribution of biomass and abundance of zooplankton were significantly correlated with both water temperature and salinity. Community cluster analysis indicated the similarity of the summer and autumn groups of zooplankton, and mouth area group and inner bay group could be divided in all seasons. Although the zooplankton communities in this study had not represented significant difference compared to the pattern in the 1980s, the health of marine ecosystem of Xinghuawan Bay is threatened by increasing economic activities (e.g. power plants) now and should pay more concern.