摘要
根据2007年5月、2008年5月和6月在长江口近海春季的底拖网调查资料,对该海域鱼类的种类组成、资源量变化、群落结构多样性及优势种类长度谱进行了分析。调查共捕获鱼类187种,带鱼在三次调查中占据绝对优势,其渔获量均占总渔获量的50%以上,其它优势种类,除小黄鱼、刺鲳、银鲳外,均为小型非经济种类。另外,冷温性的鳄齿鱼也成为优势种。多样性较高的区域主要分布在50—100m等深线之间,并且2008年的位置相对于2007年向东北方向偏移。群落中鱼类长度谱主要集中在3—33cm之间,带鱼、小黄鱼、竹筴鱼等种类优势长度组比较集中,并且个体相对较小。鱼类群落的这种演替和时空分布的异质性,是外界干扰下群落内自然选择的结果,是生物生存、繁衍及维持生态系统相对稳态的一种策略。
Based on the bottom trawl survey data in May, 2007 and May and June, 2008 in the Changjiang River estuary offshore waters, the species composition, variation of biomass, diversity of community structure and size spectra of dominant species were analyzed. There were 187 species of fishes, which were mainly of warm temperate and warm water species, and to a less extent offshore species and coastal species. Trichiurus haumela was the absolutely dominant species in the three surveys, and its biomass was beyond 50% of the total catch. The other dominant species, excluding Pseudosciaena polyactis, Psenopsis anomala and Pampus argenteus, were small-size noncommercial species. In addition, cold temperate species Champsodon capensis became a dominant species in the Changjiang River estuary offshore waters. Higher diversity of fish community structure mainly distributed around the 50-m isobath in May 2007, and between the 50-m and 100-m isobath in May and June 2008. The higher diversity position in the Changjiang River Estuary in May 2008 moved northeastwards relative to the position in May 2007. The size spectra of fish community were mainly from 3 to 33cm. In particular, the size spectra of dominant species, such as Trichiurus haumela, Pseudosciaena polyactis and Tra- churus japonicus, were narrower; and their populations were characterized by small size individuals, especially in June, 2008, indicating that the recruitment population dominated the biomass of fishery resource in the Changjiang River estuary offshore waters. The succession and heterogeneity of distribution in fish community were the results of natural selection under the control of outside disturbance, and were also a strategy that were helpful in ensuring fish survival, reproduction and maintaining the equilibrium of the ecosystem.
出处
《海洋与湖沼》
CAS
CSCD
北大核心
2011年第1期32-40,共9页
Oceanologia Et Limnologia Sinica
基金
全球变化研究重大科学研究计划项目
2010CB951204号
国家重点基础研究规划(973)项目
2011CB409805号
国家自然科学基金项目
30490233号
关键词
长江口
群落结构
多样性
长度谱
The Changjiang River Estuary, Community structure, Diversity, Size spectra
