三角帆蚌对精养鱼塘水体主要水质因子的调控

Freshwater Mussel,Hyriopsis Cumingii Lea As a Biocontrol Tool to Regulate Eutrophical Farming Water

利用三角帆蚌作为调控水质的生物过滤材料,建立蚌单养与鱼蚌混养的两种生物调控系统并与当地传统的精养鱼塘养殖系统模式作同步比较,分析了三角帆蚌对水体的主要水质因子变化及鱼产量的影响.养殖6个月后,鱼蚌混养生物调控系统水质优良,其中,鱼蚌混养水体中单胞藻总数为340万个/m l,蓝藻与绿藻数量之比(蓝绿比)为1:1.8,DO值为7.5 mg/L,氨氮为2.42 mg/L,总氮为2.76 mg/L,磷酸磷为0.06 mg/L,总磷为0.11 mg/L,COD为36.0 mg/L,悬浮物为30.2 mg/L,蚌成活率为75.0%,鱼类成活率为71.0%.蚌单养的水体中单胞藻总数为86万个/mL,蓝绿比为2.1:1,DO值为7.5 mg/L,氨氮为2.00 mg/L,总氮为2.14 mg/L,磷酸磷为0.04 mg/L,总磷为0.07 mg/L,COD为20.0 mg/L,悬浮物为8.0 mg/L,蚌成活率为85.0%.但其蓝绿比则表现为蓝藻爆发型.作为无蚌对照组的养鱼系统中,水质逐渐恶化,鱼类生长受到抑制,易发生病害,鱼类成活率仅为58.8%.研究结果表明:鱼蚌混养系统可有效地改良水质,提高鱼类的存活率.

To discuss hyriopsis cumingii Lea g capability of regulating eutrophical water, the mussel was chosen as the water quality regulation bio - tool. Two experimental systems of water bio-regulation were established accordingly ： （ 1 ） simplex mussel cultivating system, （2） mussel-fishes co-cultivating system. The traditional fish cultivating system was also established as control system. Finally, the main water factors of fishpond water in lakeshore and the impact of fish yield were analyzed. Here axe the results, after 6 months cultivation, the quality of the water in experimental systems were good. In the mussel - fishes co-cultivating system, the level of DO was 7. 5 mg/L, NH3 - N 2.42 mg/L, TN 2. 76 mg/L, PO4^3- - P 0.06 mg/L,TP 0. 11 mg/L, COD 36.0 mg/L, suspended substance 30. 2 mg/L and algae 3.4 × 10^6 ind. / mL; the survival rate of mussel was 75.0% , fish 71.0% ; the ratio of the quantity of Cyanophyta to Chlorophyta （ Ra for short） was 1 ： 1.8. In the simplex mussel cultivating system, the level of DO was 7.5mg/ L, NH3 -N 2.00 mg/L, TN2.14 mg/L, PO4^3- - P0. 04 mg/L, TP0.07 mg/L, COD 20.0 mg/L, suspended substance 8.0 mg/L and algae 8.6 × 10^5 ind./mL; the survival rate of mussel was 85.0%. But the Ra was 2. 1 ： 1, which indicates that this community may have water bloom in the future. In the control group, water quality worsened. The growth of fish was restrained and the worse water quality even threat- ened the survival of the fish. the survival rate of fish was only 58.8%. The results show that the mussel - fishes co-cultivating system efficiently decontaminated the water and increase the survival rate of fish to some extent.