东、黄海沙海蜇暴发对游泳动物群落结构的影响

The effects of Nemopilema nomurai blooming on nekton community structure in the East China Sea and Yellow Sea

利用2009年秋季在东海北部和黄海南部调查的数据,研究了沙海蜇(Nemopilema nomurai)暴发对游泳动物种类组成、资源密度、多样性和生物个体的影响。结果表明:沙海蜇暴发海域游泳动物总种类数为58种,其中鱼类、甲壳类、头足类种类数分别为38、11、9种;沙海蜇非暴发海域游泳动物总种类数为65种,其中鱼类、甲壳类、头足类种类数分别为43、16、6种。其它各项多样性指数也均表现为暴发海域低于非暴发海域。沙海蜇暴发海域的游泳动物重量CPUE、尾数CPUE和平均体重分别为155.13 kg·h-1、3 733 ind·h-1和41.56 g;非暴发海域的游泳动物重量CPUE、尾数CPUE和平均体重分别为408.69 kg·h-1、12 723 ind·h-1和32.12 g。重量CPUE和尾数CPUE均表现为暴发海域显著低于非暴发海域,平均体重则表现为暴发海域大于非暴发海域。在两类海域的6个共同优势种中,暴发海域优势种的IRI、重量CPUE和尾数CPUE均显著低于非暴发海域。除小黄鱼(Larimichthys polyactis)外,其它5种共同优势种的平均体重均是暴发海域大于非暴发海域。鱼类和甲壳类对于沙海蛰的暴发较为敏感,头足类对于沙海蛰暴发的敏感性相对较低。生物学测定数据表明,沙海蜇暴发海域的带鱼(Trichiurus japonicus)个体大于非暴发海域(P<0.05),而两类海域的小黄鱼个体大小则没有显著性差异(P>0.05),表明小黄鱼对于沙海蜇暴发海域的环境适应性强于带鱼。沙海蛰暴发和非暴发海域游泳动物群落和个体等方面的差异性与生物对灾害环境的回避和适应性具有直接的关系。

The species composition,resource density,diversity and individual of nekton influenced by N.nomurai blooming were studied based on data collected in the north East China Sea and south Yellow Sea in autumn 2009. Results showed that there were 58 species of nekton,including 38,11,9 species of fish,crustaceans and cephalopods respectively in N. nomurai blooming waters; there were 65 species of nekton,including 43,16,6 species of fish,crustaceans and cephalopods respectively in no-blooming waters. The other nekton diversity indices of N. nomurai blooming waters were also lower than that of no-blooming waters.The weight CPUE,individual CPUE and average body weight of nekton was 155. 13 kg·h^- 1,3 733 ind·h^-1and 41. 56 g respectively in N. nomurai blooming waters. The weight CPUE,individual CPUE and average body weight of nekton was 408. 69 kg · h- 1,12 723 ind ·h- 1and 32. 12 g respectively in no-blooming waters. Both weight CPUE and individual CPUE were lower in N. nomurai blooming waters than that of noblooming waters,but average body weight showed a contrary tendency. The IRI,weight CPUE and individual CPUE of dominant species in Nemopilema nomurai blooming waters were all significantly lower than that of noblooming waters in six common dominant species. In addition to the small yellow croaker（ Larimichthys polyactis）,average body weight of other five kinds of common dominant species in N. nomurai blooming waters was larger than that of no-blooming waters. Fish and crustaceans were more sensitive,but sensitivity of cephalopods was relatively low for N. nomurai blooming. The biological determination data indicated that the size of Trichiurus japonicus in blooming waters was significantly greater than that of no-blooming waters（ P〈 0. 05）,but L. polyactis showed no significant difference（ P 〉0. 05）. It indicated that L. polyactis had more environment adaptability than Trichiurus japonicus for N. nomurai blooming waters. The nekton community and individual differences in different N. nomurai blooming waters had direct relationship with their ability of avoiding disaster environment and adaptability.