莱州湾头足类的群落结构及其与环境因子的关系

Community structure of Cephalopods and its relationships with environmental factors in Laizhou Bay, Bohai Sea

为了掌握莱州湾头足类的资源现状,根据2011—2012年进行的9个月份的底拖网调查数据,研究了莱州湾头足类的群落结构及其与环境因子的关系。结果显示,148网次共捕获头足类6种,隶属于3目、3科、4属。头足类生物量及个体数均以10月最高、3月最低,周年平均值分别为3 111.39 g/h和723.54个/h。枪乌贼为莱州湾头足类的绝对优势种,其周年的相对重要性指数为13 097。头足类个体数的空间分布随月份变化,6—7月以莱州湾中南部密度较高,8—11月以莱州湾中北部密度较高,3—5月头足类的密度整体较低。CLUSTER和MDS分析将9个调查月份分为4个群组,ANOSIM分析显示群组两两间的群落结构均呈显著性差异,SIMPER分析表明枪乌贼对群组区分的贡献最大。头足类的个体数分布与浮游动物密度的相关性最高。生殖洄游和越冬洄游是影响莱州湾头足类空间分布季节变化的首要因素。研究结果可为莱州湾头足类资源的可持续利用和保护提供科学依据。

The community structure of Cephalopods and its relationship with environmental factors were analyzed based on the bottom trawl data of nine months from May 2011 to April 2012, in order to reveal the resource status of Cephalopods in Laizhou Bay. A total of 6 species belonging to 3 orders, 3 families, 4 genera, were collected by148 hauls. Both the biomass density and the individual density were highest in October 2011 and lowest in March2012. The annual average of biomass density and individual density were 3 111.39 g/h and 723.54 ind/h, respectively. Loligo sp. was the dominant species, with the annual index of relative importance（IRI） reaching up to13097. The spatial distribution of individual density of Cephalopods changed with different month in Laizhou Bay.The individual density of Cephalopods was the highest in the central and southern Laizhou bay from June to July,and the highest in the central and northern Laizhou bay from August to November 2011. The individual density of Cephalopods were very low from March to May. CLUSTER and MDS analysis indicated that 9 months were divided into 4 groups at 85% similarity level. ANOSIM analysis indicated that the community structure of Cephalopods of random two groups were significantly different. SIMPER analysis indicated that Loligo sp. contributed the most to the group distinguishing. Pearson correlation analysis indicated that the density of zooplankton matched the density of Cephalopods best. Reproductive migration and wintering migration were the principal influence factors on the variation of spatial distribution of Cephalopods in Laizhou Bay. The present results would be helpful to better utilizing and protecting the Cephalopods resources in Laizhou Bay.