五大连池的5~#池渔业资源环境现状及合理利用

Current Status of Fishery Resources, Environment and Exploitation in the Fifth Pond in Wudalianchi Lake

2012年春、夏、秋季调查五大连池的5~#池水质和生产力,并于2012年6月5日和7日放入体质量(1.00±0.25)kg的鲢Hypophthalmichthys molitrix、鳙Aristichthys nobilis和体质量(6.00±2.5)g的匙吻鲟Polyodon spathula,研究其生长。结果表明:该池水质受环境影响而剧烈变化,透明度、氨氮和磷含量达到或超过国家地表水Ⅳ类水质标准,溶解氧量达到Ⅰ类水质标准。5~#池中发现浮游植物8门79种属,平均生物量为6.287mg/L;浮游动物生物量5.49mg/L;春、夏、秋叶绿素a含量分别为15.29μg/L、63.48μg/L、13.42μg/L,年平均30.73μg/L。利用浮游生物量评估5~#池鲢、鳙年产量分别为37.74t和46.73t,鲢、鳙生产量为47.175kg/hm^2和58.35kg/hm^2;而用叶绿素a含量估算鲢的年产量为61.49t,生产量75.186kg/hm^2;黑白瓶法估算鲢、鳙年产量分别为44.6t和43.01t,鲢、鳙生产量55.65kg/hm^2、52.8kg/hm^2。8月15日,鲢、鳙及匙吻鲟体质量分别为1.5kg、2.1kg和0.2kg,增重率分别为7.14g/d、15.71g/d和2.77g/d,生长速度较快。根据水质和生物量初步判断:5~#池接近富营养化。5~#池利用得当不仅可以提高湖泊的经济效益,还能防治湖泊的富营养化。

The water quality, primary productivity and fish production were analyzed and growth of silver carp（Hypophthalmichthys molitrix）, bighead carp（Aristichthys nobilis）and paddlefish（Polyodon spathula）stocked on 5, and 7 in June was investigated in the Fifth Pond in Wudalianchi Lake in spring, summer and fall of 2012. The results showed that water quality was found to be change drastically with environmental influence in the Fifth Pond, transparency, ammonia nitrogen and total phosphorus levels being within or beyond fourth grade of national water quality for surface water, and with dissolved oxygen within or higher than first grade for surface water. There were 8 phyla and 79 species or genera of phytoplankton in the Fifth Pond, with average phytoplankton biomass of 6.287mg/L and average zooplankton biomass of 5.49 mg/L. Content of chlorophyll a in the pond was 15.29 μg/L in spring, 63.48 μg/L in summer, and 13.42 μg/L in fall, with annual average value of 30.73 μg/L. There was higher productivity level in the pond than others in the lake, phytoplankton biomass and chlorophyll a content being far higher than the average. Silver carp productivity of 47.175kg/hm-2 was estimated by phytoplankton biomass and bighead carp productivity of 58.35 kg/hm-2was estimated by zooplankton biomass. Silver carp productivity of 75.186 kg/hm-2was estimated by chlorophyll a content and 55.65 kg/hm-2by white and black bottlemethod. Bighead carp productivity of 52.8 kg/hm-2was calculated by white and black bottle method. Annual silver carp production of37.74 tons was estimated by phytoplankton biomass, and annual bighead production of 46.73 tons by zooplankton biomass. Annual silver carp production of 61.49 tons was calculated by chlorophyll a content and 44.6 tons by white and black bottle method. Annual bighead carp production of 43 tons was estimated by white and black bottle method. Body weight was found to be 1.5 kg in silver carps with weight gain of 7.14 g/d, 2.1 kg in bighead carp with weight gain of 15.71 g/d and 0.2 kg in paddlefish with weight gain of 2.77g/d, showing god growth on 15 in August. The water analysis revealed that the water in the Fifth Pond was close to eutrophication, indicating that full use of the pond not only lead to improve the economic benefit in the lake, but also will exert positive effects on prevention and control of eutrophication.