岱衢洋虾类多样性的季节变化

根据2010年春季(5月)、夏季(8月)、秋季(11月)与2011年冬季(2月)对岱衢洋进行的共4个航次的底拖网渔业资源调查资料,对该海域的虾类多样性进行了分析。结果表明:共捕获虾类13种,分别隶属于8科10属;生物量与尾数密度均以秋季为最高,而春季则正好相反,且该两季的生物量与资源尾数密度间差异均显著(P<0.05);生物量与平均底盐呈两次曲线相关(P<0.05);葛氏长臂虾为四季的相同优势种;Margalef丰富度指数(D)、Shannon-Wiener多样性指数(H′)和Pielou均匀度指数(J′)的最大值均出现在夏季,而冬季正好相反,另外,D值、H′值夏、秋两季高,冬、春两季低,与较外海域的情况正好相反,这主要是其对底层水温季节变化的一种响应。

Seasonal Variations of Diversity of Shrimps in Daiquyang

Based on the data of bottom trawl surveys in Daiquyang during spring (May),summer (August),autumn (November) 2010,and winter (February) 2011,the species diversity of shrimps was analyzed.Sweeparea method and analysis of variance were used here.The results indicated that: A total of 13 species of shrimps were caught by bottom trawl,which belonged to 10 genera,of 8 families.Both the biomass and the abundance density of shrimps reached the maximum in autumn,but decreased to the minimum in spring,and the difference in the biomass and number abundance density was significant (P<0.05).The relationship btween the biomass and average bottom sea water salinity can be denoted by binary curve (P<0.01).Palaemon gravieri was the dominant species for all the year.The Margalef richness index (D),Shannon-Wiener diversity index (H′) and Pielou evenness iddex(J′) were highest in summer and lowest in winter.In addition,the Margalef rich ness index (D) and Shannon-Wiener diversity index (H′) in summer and autumn were higher than those in winter and spring in Daiquyang,however,which was contrary in the offshore waters,the opposite phenomenon between Daiquyang and offshore waters was mainly due to its response to the seasonal variations of bottom sea water temperature.