珠江口南沙海域秋季渔业资源群落结构特征

根据2015年11月珠江口南沙海域的渔业资源调查资料,对该海域秋季渔业资源群落组成、优势种和生物多样性等群落结构特征进行了初步研究。结果表明,该海域共出现渔业生物40种,以鱼类和甲壳类为主。其中,底层鱼类21种,中上层鱼类3种,甲壳类16种。相对重要性指数(IRI)可用来度量物种的生态优势度,秋季优势种类有亨氏仿对虾(Parapenaeopsis hungerfordi)和锐齿(Charybdis acuta)2种(IRI≥1 000)。该区域内各站位质量渔获率为0.63~11.15 kg·h~(-1),平均为4.23 kg·h~(-1);尾数渔获率为84~885尾·h~(-1),平均为433尾·h~(-1)。Shannon-Wiener多样性指数(H')为2.07,Margalef丰富度指数(D)为1.64,Peilou均匀度指数(J')为0.59。分析表明,该海域渔获物以小型经济甲壳动物和经济幼鱼为主,渔获个体偏小,总体上多样性空间差异不大。与该区域2002年同月份的调查数据相比,目前渔获物多样性下降明显,群落结构相对简单。

Community structure of fishery resources from the Nanshawaters of Pearl River Estuary in autumn

According to the fisheries resources data collected from the Nansha waters of Pearl River Estuary in November 2015,we investigated the community structure,dominant species and diversity of fishery resources in this area,and 40 fishery species,mainly fishes and crustaceans,were found,including 21 demersal fishes,3 pelagic fishes and 16 crustaceans.The index of relative importance (IRI) was used to measure ecological dominance of species to decide the role each species played in the community.The dominant species were Charybdis acuta and Parapenaeopsis hungerfordii in autumn,whose IRIs were higher than 1 000.The range of catch rates in weight was 0.63~11.15 kg·h-1 (average:4.23 kg·h-1).The range of catch rates in individual number was 84~885 ind·h-1 (average:433 ind·h-1).The average Shanon-Wiener diversity index (H'),Pielou evenness index (J') value and Margalef richness index (D) of fishery resources in autumn were 2.07,1.64 and 0.59,respectively.The analysis shows that sizes of the catch were generally small,and the catch mainly consisted of small commercial crustaceans and juveniles of commercial fishes.The spatial distribution of diversity of catches had little variation of in all stations.Compared with the fisheries catches in autumn 2002,the species diversity declines and the community structure is relatively simple at present.