不同池塘养殖模式的环境氮磷负荷及其水质特征

Environmental nitrogen and phosphorus loading and water quality of three culture methods in ponds

2008年3月至2009年1月研究了广东海丰县东关联安围湿地两种投饵养殖模式——对虾主养(半集约化养殖)和虾蟹混养(半集约化养殖)海水池塘的环境氮磷负荷和养殖水体氮磷含量的周年变化情况,并以不投饵的塭围虾贝混养(粗放式养殖)模式为对照。3种模式中,池塘单位面积环境氮、磷负荷以对虾主养模式最高,分别为36.52 kg/hm2和7.39 kg/hm2;虾蟹混养模式次之,分别为1.49 kg/hm2和0.52kg/hm2;而塭围虾贝混养模式最低,分别为–2.47 kg/hm2和–0.34 kg/hm2。每月1次对3种模式养殖过程中水体的总氮、硝酸氮、亚硝酸氮、氨氮和总磷及磷酸盐含量进行监测,结果表明,与养殖环境氮磷负荷大小相对应,塭围虾贝混养池塘水质最好,虾蟹混养池塘次之,而对虾主养池塘水质最差,这种现象尤其在养殖后期更为明显。

In this paper, the environmental nitrogen and phosphorus loading and nitrogen and phosphorus contents in water of two methods of pond culture with feeding （semi-intensive monoculture of shrimps and semi-intensive polyculture of shrimps and crabs）, and one method of pond culture without feeding, （extensive polyculture of shrimps and shellfish） were analyzed in the ponds of Haifeng Dongguan Lian＇anwei wetland areas. The results showed that in the three culture methods, semi-intensive monoculture of shrimp produced most nutrient discharge into the environment-nitrogen loading of 36.52kg/hm2 and phosphorus loading of 7.39 kg/hm2, following by those of semi-intensive polyculture of shrimps and crabs, with nitrogen loading of 1.49kg/hm2 and phosphorus loading of 0.52 kg/hm2, and extensive breeding did not discharge but instead, took up 2.47 kg/hm2 nitrogen and 0.34kg/hm2phosphorus from water. According to the monthly measurement of the levels of nitrate, nitrite, ammonia, total nitrogen, phosphate, and total phosphorus in seawater from March of 2008 to January of 2009, it indi cared that the water quality of semi-intensive monoculture of shrimp was the worst among the three culture methods, followed by semi-intensive polyculture of shrimp and crabs and the extensive polyculture of shrimps and shellfish has the best water. This situation became more significant during the later period of culture.