珠江三角洲密养池塘营养物质收支的研究

Nutrient Budget of Intensive Fish Ponds in Pearl River Delta

对珠江三角洲的几个典型基塘进行了一个养殖周期的跟踪调查,结果发现密养池塘水中的N比对照点有明显的升高,而P则没有明显升高;在养殖周期内密养池塘中的营养物质并没有随鱼的生长、摄食量和排泄量的增加而逐渐增加,说明池塘的自净机制可以支持当前的放养量。营养物质平衡计算结果表明,池塘中营养物质N的输入饲料占90%～98%,N的输出鱼类仅占总输出的20%～27%,沉积的N占54%～77%。营养物质P的输入饲料占97%～98%,鱼类P仅占总输出的8%～24%,沉积的P占72%～89%。珠江三角洲的密养池塘,由于其封闭性,养殖产生的废物不易外排,只能依靠池塘的自净作用消解废物。

Investigation on several typical intensive fish ponds in Pearl River Delta indicated that nutrient N increased significantly while nutrient N did not increased significantly. Nutrients in the ponds did not increase with the growth of fish, feeding and discharge, which indicated that the self-cleaning mechanism still support the cultured density. N budget indicated that feed took up 90%～98% as input, fish cultured only took up 20%～27% as output, and deposited N was 54%～77%. P budget indicated that feed took up 97%～98% as input, fish cultured only took up 8%～24% as output, and deposited P was 72%～89%.