疏浚泥浆排放对渔业生产的影响及其对策研究　Ⅰ对养殖鱼类生长、饲料转化率和池塘鱼产量的影响

Influence About the Dredged Sludge on Fisheries and Its Countermove Ⅰ The effects of dredged sludge on fish growth,feed conversion ratio and yield of pond fish culture

本文报道了河道疏浚泥浆排放对养殖鱼类生长、饲料转化率和池塘鱼产量影响的研究结果。室内试验结果表明，当水中泥浆达到一定浓度后，鱼的生长率和饲料转化率均随浓度的升高而下降，但鱼的种类不同，对泥浆水的耐受能力也不相同，其中白鲢鱼种（平均体重0．8079）生长受影响的浓度最低，为0．144g／l，鲫鱼种（平均9．889g）次之（0．256g／l），草鱼种（平均1．373g）最高（0．448g／l），这除与鱼种的规格有关外，还与不同种类的生活习性和食性有关。同一浓度条件下，小规格鱼苗的成活率较同种较大规格鱼苗为低。当泥浆浓度较低时，泥浆的添加频率不会明显降低鱼的生长速度和饲料转化率，但当泥浆量增加到一定值时，则添加频率越高，对鱼的影响越大。参考室内的试验结果，通过池塘对比饲养试验，比较、分析了不同泥浆添加量条件下各试验组鱼的群体生长率和鱼产量的差异，提出了施工期间指导养殖生产的科学措施与方法。

The influence about dredged sludge on fish growth, feed conversion ratio and the production of pond fish culture and its countermove have been studied and reported. Indcor experiments showed that the growth rate and feed converson ratio of the fish decreased with the increasing of the sludge concentration when the sludge content was up to some extent. It was found that the tolerance of fish for sludge levels was based on not only the kinds of fish and its size, but also the living environment and feeding habit of the fish. The sludge concentration affecting the growth of silver carp fingerlings (the average body weight 0. 807g) was the lowest (0. 144 g/l), which was lower than that of tbe crucian carp fingerlings (0. 256g/l)and the grass carp fingerlings (0. 448g/l), that their average body weight was 9. 889 g and 1. 373 g respectively. The survival rate of the quickly growing fry was higher than that of the slower growing fry of the same species when they were exposed to the same sludge concentration. At the lower sludge concentration,the adding frequency of sludge did not affect the growth rate and feed conversion ratio significantly.Increasing the sludge content to a certain extent might decrease the fish growth rate and feed conversion ratio, the more sludge was added, the greater the influence on fish was.Pond culture experiments were conducted on the basis of laboratory experiment results. The difference of the P/B coefficient and total weight gain by fish in experimental and control ponds with different adding quantity of sludge were compared and analysed. The scientific technique and countermove for directing the management in pond fish culture were provided according to the test results mentioned above.