| 摘要: |
| 长江口是我国最大的河口，河口地区通江达海，工、农业和交通业发达，是我国经济的重要枢纽与中心；河口两侧是著名的舟山渔场和吕四渔场，在我国海洋渔业生产上占有重要地位。
随着长江三角洲地区的进一步开发与经济发展，人类的社会活动对河口的影响日益严重，河口生态环境问题愈来愈突出。可见，河口生态环境本身就是一个非常严峻而重要的课题。
为给三峡水利枢纽工程(简称三峡工程)的可行性论证提供依据，我们就三峡工程对河口及邻近海域生态环境的影响进行了初步研究。自1985年8月至1986年10月进行了周年多学科的综合调查，调查范围为东经121°10'-124°00'，北纬30°20'-32°00'的河口区水域，调查区设48个环境因子调查站，30个游泳生物调查站，如图1所示(各专题根据各自需要又增减一些调查站)。本文系根据本调查研究的结果所进行的综述，各专题研究详见本集各文。 |
| 关键词: 三峡工程、长江口、生态与环境 |
| 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2025号 |
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| IMPACTS OF THE THREE GORGES PROJECT ON THE ECOLOGY AND ENVIRONMENT OF THE CHANGJIANG RIVER ESTUARY AND ADJACENT WATERS |
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Liu Ruiyu(J. Y. Liu), Luo Bingzheng
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Institute of Oceanology, Academia Sinica
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| Abstract: |
| The Three Gorges Dam now under planning will drastically change the seasonal distribution pattern of the runoff (it wi1l increase from January through April, and decrease in October). A multidisciplinary investigation has been conducted on the impact of its change on estuarine environment and distribution pattern of marine fishes and invertebrates. The relationship between the Changjiang (Yangtze) River runoff and the hydrographic, hydrochemical and sedimentary environments, the primary productivity, the species composition and abundance of phyto-and zoo-plankton, benthos and nekton in the Changjiang River Estuary and adjacent waters has been analysed. The in luence of environmental factors including the Changjiang runoff on the biological community and stock size of economic species has also been discussed.
Results of monthly survey and data analysis showed that after completion, the Three Gorges Reservoir will store water in the rainy season to the levels of 150一180 meters and .the distributional range of the hrackish water in the Changjiang River Estuary wi1l be changed from the original 4550k㎡ to 1800k㎡and the estuarine salinity will rise by 1--4. The 30 isohaline wi1l shrink back to the mouth. The mean salinity gradient will rise simu1taneously, the contents of nutrient salts and organic compounds in the water will decrease accordingly, .and the high concentration area will also shrink back towards the estuary.
The change of oceanographic environment will change the species composition, the distribution pattern and abundance of living organisms; the biological productivity will also de?rease.
Results of the analysis of fish and invertebrate samples and oceanographic data showed that the change of water level of the Three Gorges Reservoir will affect the stock of important fishes and invertebrates to various extents. Caloulation showed that the stock index of marine fish will be ,reduced by about 5% to 15%. The location of the center of fishing grounds will also be changed somewhat. In the period from January to April, increasing runoff will benefit the reproduction and recruitment of fish population. |
| Key words: THREE GORGES PROJECT,ECOLOGY AND ENVIRONMENT,CHANGJIANG RIVER ESTUARY |
