珠江口中华白海豚自然保护区鱼类群落多样性分析

摘要：【目的】分析珠江口中華白海豚自然保护区海域鱼类结构组成及其多样性，为开展中华白海豚保护及保护区生物多样性研究提供基础资料。【方法】2015年9月（秋季）和2016年3月（春季）以拖网船对保护区海域进行拖网调查，运用生物量和丰度法对渔获组成进行统计分析，计算调查海域内鱼类资源生态特征指数，并采用丰度生物量比较曲线法评估鱼类群落受干扰程度。【结果】两个航次调查共捕获鱼类57种，隶属于13目37科51属。2015年9月（秋季）调查的平均鱼类生物量1.63 g/m2，平均丰度177.9×10-3尾/m2；2016年3月（春季）调查的平均鱼类生物量0.43 g/m2，平均丰度25.2×10-3尾/m2。棘头梅童鱼（Collichthys lucidus）、凤鲚（Coilia mystus）、六指马鲅（Polynemus sextarius）和短吻鲾（Leiognathus brevirostris）为春秋两季共有优势种；Shannon-Weiner多样性指数（H"）、Pielou均匀度指数（J"）和Margalef丰富度指数（D）3项生态特征指数均表现为秋季高于春季。2015年9月（秋季）珠江口中华白海豚自然保护区海域鱼类群落的生物量优势度曲线位于丰度曲线之下，W为负值（-0.068），鱼类群落结构受到严重干扰；2016年3月（春季）该海域鱼类群落的生物量优势度曲线位于丰度曲线之上，W为正值（0.056），鱼类群落结构未受干扰。【结论】珠江口中华白海豚自然保护区海域鱼类现存资源量水平呈下降趋势，渔业资源有所衰退；鱼类群落结构在秋季受外界干扰较明显，春季则趋于稳定。珠江口中华白海豚自然保护区海域水质已受到轻度污染，虽然目前尚适合鱼类的生长和繁育，但今后须对其进行实时监测，加强水质与生态环境的保护。

关键词： 鱼类群落结构；多样性；生物量；丰度；珠江口中华白海豚自然保护区

中图分类号： S932.4 文献标志码：A 文章编号：2095-1191（2018）05-1000-08

Abstract：【Objective】Structure and diversity of fish community in Sousa chinensis nature reserve of Pearl River Estuary waters were studied to provide basic reference for the protection of S. chinensis and biodiversity in this area. 【Method】Trawl surveys were conducted in the waters of nature reserve in September， 2015（autumn） and March， 2016 （spring）. By using the biomass and abundance method， the composition of fishery catches was counted and analyzed to measure the ecological characteristics index of fish resource in the survey area. Besides， the disturbance status of fish community was assessed by abundance biomass comparison curve method. 【Result】Totally， fifty-seven fish species were caught in two cruises survey， which belonged to 51 genera， 37 families， and 13 orders. In September， 2015（autumn）， the average biomass and abundance of fish was 1.63 g/m2 and 177.9×10-3 ind/m2 respectively， with the average biomass and abundance being 0.43 g/m2 and 25.2×10-3 ind/m2 respectively in March， 2016（spring）. Collichthys lucidus， Coilia mystus， Polynemus sextarius and Leiognathus brevirostris were dominant species of both seasons. In autumn， all of the ecological characteristics indexes， including the Shannon-Weiner diversity index（H"）， Pielou evenness index（J"）， and Margalef abundance index（D）， were higher than those in spring. In September， 2015（autumn）， the dominance curve of biomass dominance in the fish community of S. chinensis nature reserve of Pearl River Estuary waters was below the abundance curve. W was a negative value（-0.068）， indicating that the fish community was under severe disturbance. On the contrary， in March， 2016（spring），the location of the biomass dominance curve was above the abundance curve. W was 0.056， showing that fish community was not disturbed. 【Conclusion】The storage of fish resources in S. chinensis conservation area of Pearl River Estuary waters is low， which indicates a declining trend of fishery resources during these years. The fish community structure is comparatively stable in spring， but is distinctively affected by external disturbance in autumn. Water in the S. chinensis nature reserve in the Pearl River Estuary has been under mild contamination. Though it is still suitable for fish growth and development， real-time measures should be taken to monitor and protect the water and ecological condition in the future.