高温季节鳜及饵料鱼池塘水质调查研究

于高温多雨季节对广东省清远市鳜（Siniperca chuatsi）养殖基地的6个鳜及饵料鱼养殖池塘发病、用药情况及水质进行调查分析。结果表明,单独施用抑菌类药物,鳜出血病容易复发,而同时施用增强动物免疫力与减少应激行为药物及抑菌类药物,鳜出血病不易复发。鳜及饵料鱼塘发病期间,水中氨氮（NH4＋-N）质量浓度始终高于1.0 mg.L-1,亚硝酸盐氮（NO2--N）质量浓度高于0.18 mg.L-1,氮磷比（N/P）也有偏高的情况发生,而所调查的6个池塘硝酸盐氮（NO3--N）质量浓度均随养殖时间延长而逐渐下降。NH4＋-N与NO2--N质量浓度过高可能预示鳜的细菌性疾病即将发生。可按实际情况种植浮萍等植物吸收过量NH4＋-N;开增氧机保持水中高溶解氧（DO）以降低NO2--N质量浓度或投放减少动物应激行为的药物。N/P过高可适当释放磷肥以调节水质。

Research on water quality of ponds for Siniperca chuatsi and bait fish in hot season

In hot and rainy seasons,we investigated the disease incidence,drug use and water quality of 6 ponds for Siniperca chuatsi and bait fish in the breeding base in Qingyuan,Guangdong province.The results suggest that hemorrhage of S.chuatsi easily relapses by adding antibacterial drugs,but not by adding both antibacterial drugs and drugs which enhance immunity and reduce stress behaviors.During the incubation period,the concentration of ammonia nitrogen is always higher than 1.0 mg·L-1,and that of nitrite nitrogen is higher than 0.18 mg·L-1;N/P ratio is relatively high sometimes,and the concentration of nitrate nitrogen in 6 survey ponds gradually decrease along with culturing time.Thus,high concentration of ammonia nitrogen and nitrite nitrogen indicates bacterial diseases of S.chuatsi may occur soon.To solve this,plants such as duckweed may be grown to absorb the excess ammonia nitrogen;aerator may be applied to maintain high dissolved oxygen to reduce the concentration of nitrite nitrogen;drugs may be added to reduce stress behaviors of animals.To avoid high N/P ratio,appropriate addition of phosphate may regulate the water quality.