| 摘要: |
| 长江口区是我国最大的河口渔场,开发历史悠久,水产资源丰富。它位于东海北部，西靠大陆,有长江入海,北接吕四渔场,南邻著名的舟山渔场,东至东经124°00′,包括长江下游上海江段至佘山以东的广大水域。
长江口区的环境特点是处于沿岸水和长江冲淡水为主的低盐水系和外海高盐水系的混合区。底质以粘土质软泥、细粉砂为主。水深一般在60m以内,温、盐度变化大,以长江口引水船水文站为例,表层水温年平均为16.6℃,波动范围为5.5-27.6℃;盐度年平均为12.8,波动范围为7.19-19.9。
长江口及邻近海域水质肥沃,营养盐类和饵料生物基础丰富,是初级生产力较高的水域(刘瑞玉等,1987)。又由于水浅,地形复杂(北有长江大沙堆),造成潮流湍急,该水域成为大黄鱼、小黄鱼、带鱼和银鲳等经济种类的重要产卵场。长江口区也是夏秋季银鲳、刀鲚、凤鲚、带鱼、石首鱼类以及鲐、鲹等中、上层鱼类的重要索饵场;又是名贵种类鲥、松江鲈、中华鲟溯河或降海洄游的必经水道。河口和崇明岛近岸低盐水域还是中华绒螯蟹蟹苗和鳗苗、银鱼等的集中产区。
长江三峡工程的建造将对河口渔场及部近海域渔业资源产生什么影响,已引起人们的关注与重视。为此,进行了长江口区渔业资源调查,其目的在于了解该水域渔业资源的本底现状;并评估三峡工程建成后对渔业资源的影响,进而为持久地利用河口渔业资源提出科学依据。 |
| 关键词: 长江口区、鱼类资源 |
| DOI： |
| 分类号: |
| 基金项目:中国科学院海洋研究所调查研究报告第2068号 |
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| INVESTIGATION AND STUDY ON FISHERY RESOURCES IN THE CHANGJIANG RIVER ESTUARY |
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Yang Weixiang, Luo Bingzheng, Lu Jiwu, Tian Mingcheng, Huang Songfang, Han Guocheng, Xue Pin
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Institute of Oceanology, Academia Sinica
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| Abstract: |
| For analysing the possible effects of the Three Gorges Project on fishery resources in the Changjiang River Estuary, the fishery survey was made monthly from September 1985 to August 1986 using two-boat trawling for one hour at each of 30 stations in the surveyed water area.
According to the survey data, 63,060 fish/k㎡ of mean density, 812kg/k㎡ of mean biomass and 17,054 ton of abundance in the total area were computed for each month. The seasonal changes in these quantities of fish (the highest in autumn, and the lowest in winter) were showed obviously and trended similarly. The habitat distributions of fishes were not even either,and the concentration areas of fishes often occurred in the northeast and the mouth of estuary.
The estuary served as an important nursery ground where juvenile fish accounted for 60% in the yearly catch, which peaked in Aug. and Dec. (80.6% and 70.3% respectively)for 14 commercial fishes.
In this paper, the abundance and distribution, the ecological habits and the resouces situation of important fishes are discussed one by one. The quality of fish resources were evaluated. The result indicated that the abundance tended towards declining and the composition of length and age tended to simplifying.
The study provides a valuable baseline for analysing the effects of environment variations on fishery resources in the Changjiang River Estuary. |
| Key words: fish community,Changjiang River Estuary |
