南沙群岛海域鱼类群落结构的季节性变化研究

Research on seasonal changes of the fish structure community in Nansha Islands waters

根据2006年在南沙群岛海域生产的445艘渔船的渔捞日志,分析了该海域的鱼类群落的四季变化特征。四季全部调查海域中出现的优势种类有8种:鲷Sparidae、Carangidae、带鱼Trichiurus haumela、金线鱼Nemipterus virgatas、蛇鲻Saurida elongate、条尾绯鲤Clupea harengus、金色小沙丁Sardinella和马鲛Scomberomorus,其中鲷、金线鱼和带鱼是常年优势种。南沙群岛3个海域4个季节的Simpson指数(D)从南到北呈上升趋势,Shan-non-Wiener多样性指数(H')变化范围在2.5—4.5之间,Pielou均匀度指数(J')季节变化不明显。南沙3个海域4个季节的鱼类群落之间的相似性较低,南沙中部海域4个季节的鱼类群落空间距离相对较远,鱼种季节迁移变化以南沙南部海域波动最大,南沙中部海域相对较为稳定,南沙北部海域稳定性介于两者之间。

The authors conduct research on the seasonal characteristics of fish communities structure and diversity based on the data of 445 fishing vessel log in the Nansha Islands waters in 2006.Around all survey areas there were total eight dominant species in four seasons,which were Sparidae,Carangidae,Trichiurus haumela,Nemipterus virgatas,Saurida elongate,Clupea harengus,Sardinella and Scomberomorus.Among them,Sparidae,Nemipterus virgatas and Trichiurus haumela were dominant around all four seasons,and the rest were only dominant in some seasons.In the Nansha Islands waters,there existed an increasing tendency from south to north for the Simpson index（D）,and the Shannon–Wiener index（H＇） ranged from 2.5 to 4.5,and the Pielou index（J＇） turned out to be far from distinct.The similarity indices of species composition were relatively low during four seasons and in the three areas in the Nansha Islands waters.In the central Nansha Islands waters spatial distance of fish community structure was relatively far in four seasons.As for the seasonal migration of fish,or the fish’s movement,in the Nansha Islands waters,the strongest was in the south and the weakest was in the central,with the north in between.