崇明东滩潮沟浮游动物数量分布与变动

根据2008年4-12月对上海市崇明岛东滩潮沟进行4个季节的浮游动物调查资料,研究了崇明东滩潮沟浮游动物的数量分布及变动。结果表明,调查区浮游动物总丰度较高,四季变化明显。受潮汐作用的影响,夏、秋、冬三季落潮时丰度大于涨潮时,春季涨潮时丰度则大于落潮时。浮游动物在6条潮沟的平面分布不均匀,春季东旺沙边滩区和北八边滩区的数量明显多于近团结沙边滩区,夏、秋季分别以东旺沙边滩区和北八滧边滩区的数量最多,冬季则以近团结沙边滩区的数量最多。主要优势种细巧华哲水蚤(Sinocalanus tenellus)、中华华哲水蚤(Sinocalanus sinensis)、火腿许水蚤(Schmackeria poplesia)、四刺窄腹剑水蚤(Limnoithona etraspina)和四刺破足猛水蚤(Mesochra quadrispinosa)等数量的季节、潮汐变化及各时期的空间分布格局差异明显,其数量分布情况决定了浮游动物总数量的分布。盐度是影响冬、春季涨潮时浮游动物总丰度分布的主要因子,水温则是影响夏、秋季涨潮时总丰度分布的主要因子。此外,径流及潮流等动力因素对潮沟浮游动物数量的时空分布也产生重要影响。

QUANTITATIVE ANALYSIS OF DISTRIBUTION AND VARIATIONS OF ZOOPLANKTON IN TIDAL CREEKS OF CHONGMING ISLAND

Quantitative distribution and seasonal variations of zooplankton in the tidal creeks of Chongming Island at Dongtan (eastern flat) were studied based on seasonal investigation data obtained from April to December, 2008. The result shows that the total abundance of zooplankton was high in all seasons between over 4.50×103 ind/m3 in winter and over 10.00×10³ ind/m³ in other seasons. Due to tide effect, the abundance in flood tide was higher than that in ebb tide in summer, autumn and winter, but in spring. The horizontal distribution of zooplankton was different in six tidal creeks and among 7 main dominant species. The result also shows that the total abundance distribution was determined by Sinocalanus tenellus, Sinocalanus sinensis, and Mesochra quadrispinosa in spring, by Sinocalanus sinensis and Schmackeria poplesia in summer and autumn, and by Sinocalanus sinensis and Limnoithona etraspina in winter. In flood tide, the variation in total abundance was somehow related to temperature in spring and winter, but to salinity in summer and autumn. In ebb tide, temperature and salinity had significant correlation with the total abundance in summer and winter, but in spring and autumn. Therefore, environmental factors, such as runoff and tidal current also influenced the temporal and spatial distribution of zooplankton abundance in the tidal creeks.