摘要: |
根据1950~1995年期间对太湖水体进行的各次综合性研究结果分析:太湖水质和营养程度大致每10~15年上升一个级别,近期变化尤为明显;CODMa含量35年来增加了136%,总磷近年来以9.9%速度上升,浮游藻类80年代以来一直以蓝藻和硅藻占优势,但种群数趋于减少,细胞数剧增,局部水域蓝藻水华频发;浮游动物和底栖动物中耐污种类增多,枝角类、桡足类和环节动物、节肢动物数量则降低;鱼类种群效减少,银鱼捕捞量近年来大幅度下降;水生植被严重退化,个别湖区水草萎缩甚至消亡。初步研究表明,太湖40年多来生态环境的变化主要与人类活动关系密切,尤其与湖体污染物排放、围垦、养殖、滥捕水产品等有关。 |
关键词: 太湖 演变 水质和营营养化 水生生物 |
DOI:10.18307/1996.0402 |
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Historical evolution of water ecological setting in Taihu Lake |
Fan Chengxin
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Nanjing Institute of Geography & Limnology, Chinese Academy of Sciences, Nanjing 210008
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Abstract: |
Based on the analysis of all comprehensive research in Taihu Lake daring 1950-1995.the evolution about aquatic ecological setting was studied by means of evaluation and comparison for water quality and aquatic creature.The main pollutants (nitrogen. phosphorus and CODMn) of Taihu Lake have been raising since 1960. especially since 1980.CODMn content has increased by 136% for thirty-five years and total phosphorns went up at the speed of 9.9% in the recent years.The water quality and trophic level reached one grade in 10-15 years.Since the 1980s the dominant algae have been blue-green alga and diatom; however,the species amount of phvtoplanton gradually decreased.The algal cell number rose rapidly and the blue-green algal bloom occured frequently.The cladoceran, copepod and annelid. arthropod decreasingly came to appear in the zooplankton and zoobethos, whose pollntion-resistant species nevertheless increased.And pollution-resistant species of zooplankton and zoobenthos in-creased, and the genera of fish reduced, of which the ice fish catch greatly dropped in recent years.The degeneration appeared seriously in the aquatic macrophyte, which had withered or was contracting in Wuli Bay and Zhushan Bay.The ecological setting change over 40 years in Taihu Lake was mainly related to human activity. such as discharging polluted water, pen culture in laket excevssively catching aquatic products and so on. |
Key words: Taihu Lake evolution water quality and eutrophication aquatic creature |