辐射沙脊群南部浮游动物的生态特征

依据2007年5月(春)、8月(夏)辐射沙脊群南部所获得的浮游动物样品,分析了该海域浮游动物的分布、时空变化及其与生态环境因子的关系。结果表明,调查海域浮游动物66种(不含鱼卵和仔鱼),生态属性以暖温性、近岸低盐种类为主;浮游动物总丰度春季(1 558.57 ind/m~3)>夏季(305.79 ind/m~3);饵料浮游动物生物量春季(2 923.75 mg/m~3)>夏季(335.46 mg/m~3);水平分布均呈现中北部高、南部低的特点。调查海域中部(4～5断面)多样性指数(H’)、丰富度指数(d)及均匀度指数(J)值较其他断面要低。相关性分析表明,春季浮游动物丰度和饵料浮游动物生物量的分布变化与浮游植物的丰度密切相关,夏季则与海水平均盐度的变化相关性显著;春、夏季浮游动物总丰度分布分别取决于优势种短尾类大眼幼体(Brachyura megalopa)和小拟哲水蚤(Paraca/anus parvus)的分布。

Ecological characteristics of zooplankton over the southern radiative sandy ridge field on the continental shelf

Based on the zooplankton sampled in the southern radiative sandy ridge field on the continental shelf(121°17’～121°55’E、32°00’～32°28’N ) in May(spring) and August(summer) 2007,totally 66 species of zooplankton (not including fish eggs and juveniles) were identified.The spatial-temporal distribution and variation of the zooplankton, and their relationships with the environmental factors of the investigated area were analyzed.The ecological attributes were mainly the in-shore and low-salt species of the warm temperature zone.The zooplankton abundance in spring (1 558.57 ind/m~3) was higher than that in summer(305.79 ind/m~3),and the nutrimental zooplankton biomass was significantly higher during spring(2 923.75 mg/m~3) than that during summer(335.46 mg/m3).The abundance and the biomass were both higher in the middle and the north part than those in the south of investigated area.A pronounced decrease in Shannon’s diversity(H’),Margalef’s species richness(d) and Pielou’s evenness(J) indices was typical in the middle part of investigated area(from section 4 to section 5).It was indicated from the correlation analysis that the zooplankton abundance and the nutrimental zooplankton biomass could be related to the phytoplankton abundance in spring and the salinity variation in summer,respectively.The distribution of zooplankton abundance varied mainly depending on the distribution of Brachyura megalopa in spring,whereas depending on the distribution of Paracalanus parvus in summer.