中文摘要：

河蚬（ Corbicula fluminea）为太湖优势大型底栖动物，通过受控实验研究其对富营养水体的水质改善效果.根据太湖河蚬的自然丰度设置4组密度处理，分别为无河蚬对照组、低密度河蚬组（生物量为130 g/m2）、中密度河蚬组（260 g/m2）和高密度河蚬组（520 g/m2）.结果表明：河蚬滤食显著降低悬浮物浓度与叶绿素a含量，低、中、高密度河蚬组水体悬浮物浓度较对照组分别降低了20.85%、34.90%和53.79%，叶绿素a浓度分别降低了23.29%、48.32%和71.17%；放置河蚬还降低了水体TN、TP浓度，但是中密度河蚬组与高密度河蚬组没有显著差异.分析认为，河蚬通过滤食作用降低水体浊度、改善光照条件，有利于底栖藻类的生长及沉水植物的恢复，对富营养水体的生态修复具有重要意义；就太湖而言，河蚬对水质的改善效果可能受沉积物再悬浮造成的营养盐释放等因素的制约.

英文摘要：

Corbicula fluminea is the dominate species among the large benthic organisms in Lake Taihu. A controlled experiment was conducted to assess the effects of C. fluminea on water quality improvement with four treatments of different densities of C. flu-minea of Lake Taihu. C. fluminea was put in four groups： the none, low, medium and high densities were designed as 0 g/m2 （ control group） , 130 g/m2 , 260 g/m2 , 520 g/m2 , respectively. The results showed that, in contrast with the control group, the concentrations of suspended particulate materials of water in low, medium and high density groups significantly reduced by 20. 85%, 34. 90% and 53. 79%, respectively. Moreover, chlorophyll-a concentrations significantly reduced in C. fluminea treat-ments with the decrement of 23. 29%, 48. 32% and 71. 17%, respectively from the low to high density groups. Meanwhile, total nitrogen and total phosphorus concentrations of water reduced in C. fluminea groups, while no significant difference showed be-tween medium density and high density treatments. It revealed that C. fluminea could purify eutrophic water by filter-feeding phy-toplankton and organic suspended materials, lowering the water turbidity, and improving light conditions, which was conducive to the growth of periphyton on the lake bottom and the restoration of aquatic plants. It is suggested that C. fluminea has an important ecological significance to the restoration of eutrophic waters. However, in terms of Lake Taihu, the effect of C. fluminea on the wa-ter quality improvement may be hampered by resuspension process which releases nutrients from the water-sediment interface.