荣成俚岛人工鱼礁区游泳动物群落特征及其与主要环境因子的关系

根据2009年5月份至2010年2月份于山东荣成俚岛人工鱼礁区和对照区4个季度月的游泳动物及同步的环境调查数据,采用Margalef种类丰富度指数,Shannon-Wiener多样性指数,Pielou均匀度指数分析了鱼礁区游泳动物群落组成和物种多样性的时空分布特征,运用梯度分析法对调查区域游泳动物群落格局与环境因子进行排序分析,结合蒙特卡罗检验确定影响鱼礁区游泳动物群落结构的控制因子。调查期间共捕获游泳动物18种,隶属于8目15科,优势种为许氏平鲉(Sebastes schlegeli)、大泷六线鱼(Hexagrammos otakii)和斑头六线鱼(Hexagrammos agrammus),其中许氏平鲉在渔获量组成中占绝对优势(41%)。鱼礁区游泳动物的渔获种类数和渔获量高于各自对照区,但差异不显著(P>0.05), 季度月平均CPUE最高值出现在近岸礁区,达到830.24 g ·网^-1·d^-1。群落组成特征值上,春秋季的参数值最大,鱼礁区与对照区间并无显著差异(P>0.05)。聚类分析表明,春季、夏季和冬季均是季度月内不同区域的样方相似性较高,而秋季的远岸礁区及其对照区样方与春季各区域样方的相似性高于秋季近岸礁区及其对照区。RDA分析表明,水温对游泳动物群落组成变化的解释量为37.1%,是主要的解释因子(P=0.002)。水温和水深等环境因子主导了俚岛人工鱼礁区游泳动物群落结构的时空变化。

Nekton community structure and its relationship with main environmental variables in Lidao artificial reef zones of Rongcheng

Based on the environment and nekton data obtained from seasonal surveys in Lidao artificial reef (AR) and control zones of Shandong province between May 2009 and February 2010, this paper analyzed the species composition of nekton community in the two zones. Variations on temporal-spatial distribution patterns and community structure of nekton community were determined by using Margalef's species richness index, Shannon-Wiener diversity index, Pielou's evenness index. The relationships between abiotic environmental variables and nekton community pattern were investigated with gradient analysis, combining Monte Carlo test to determine limiting factors affecting nekton community structure of artificial reef zones. A total number of 18 fish species belonging to 15 families and 8 orders were collected during the surveys. Sebastes schlegeli, Hexagrammos otakii and Hexagrammos agrammus were the most abundant species. S. schlegeli was the absolutely dominant species in weight composition of catch(41%).The species number and catch of nekton at AR were higher than that at the control site, but the difference was not significant(P>0.05). The highest average CPUE by season of investigation zones appeared in the reef zone near shore (NA) and reached 830.24 g/(net·d) during the surveys. It was noted that the parameters of community structure were highest in spring or autumn. However, no significant differences were found in community structure parameters between artificial reef zones and the control zones (P >0.05). Cluster analysis showed that similarities among quadrats of different zones were relatively high in spring, summer and winter, while similarities among quadrats between the reef and control zones off shore in autumn and all zones in spring were higher than those NA and control zones. 37.1% of the variation in composition of nekton community was explained by water temperature in the RDA analysis, which suggested water temperature was main explanatory factor(Monte Carlo test P=0.002).The water temperature and depth were key environmental variables for temporal-spatial variation of nekton community structure in Lidao artificial reef zones.