东太湖生态环境的演变与对策

 分析了40多年来东太湖生态环境的演变,随时间的推移,东太湖的水质逐渐恶化,水体营养状态由中-富营养型向中-富-富营养型过渡,并接近富营养状态.淤积层厚度逐步上升,沼泽化趋势明显.藻类密度不断增加,种类不断减少,浮游生物和鱼类的小型化趋势明显.20世纪50年代马来眼子菜为沉水植物的优势种,但进入20世纪90年代后,挺水植物、浮叶植物的扩展和湖底的沉积物迅速於积导致了沼泽化进程的加速.东太湖的渔业产量一直呈上升趋势,自1984年网围养殖出现后,网围养殖经历了由粗放型到精养型和效益型的转变,从污染型向生态型方向发展.目前必须加强对东太湖的综合治理,进行生态恢复与重建,以维持东太湖资源的可持续发展.

Ecological environment succession and countermeasure of East Taihu Lake

The ecological environment succession of East Taihu Lake was analyzed for years past 40. With the passage of time, the water quality becomes worse gradually; trophic status shows transition from meso-eutrophic type to near eutrophication. Thickness of sediment raises gradually and tends to form marsh markedly. Density of algae increases continuously with species decreased; plankton and fish tend to be markedly less. Potamogeton malialaianus was dominant in submerged plants in 1950s; but the rate to form swampy is more rapid, because of rapid sedimentation and development of photo plankton after 1990s. Fisheries yield of the lake continues to raise. Since 1984, cage aquiculture converted from extensive to intensive and high-returned and from pollution to ecological types. The comprehensive control of East Taihu Lake must be strengthened, as well as ecological rebuilding, so as to maintain sustainable development of the lake resource.