Water quality in 22 ponds in two farms culturing Litopenaeus vannamei in the Fengxian District of Shanghai was investigated from May to September 2010. Fifteen water quality parameters were measured, including chlorophyll-a (Chla), water temperature (T), pH, dissolved oxygen (DO), transparency, total dissolved solids (TDS), chemical oxygen demand (CODMn), nitrogen (TN) and phosphorus (TP). In total, 107 groups of monitoring data were obtained and compiled as descriptive statistics. Multiple linear regression following principal component analysis was used to simulate the relationship between water quality variables and Chla in Litopenaeus vannamei culture ponds. Based on the criterion of eigenvalues greater than 1, four latent variables occupied 77.56% to the cumulative contribution to variance. Subsequent multiple linear regression analysis showed that a latent variable F had the maximum correlation with Chla and that the model was: Cchi.a=0.140+0.121F]. TP and CODMn were clearly positively correlated with chlorophyll-a: Cchi.a=-0.052+0.005CODMn+0.188TP. Phosphorus was the limiting factor for the primary productivity of the ponds. We conclude that organics and phosphorus are the main factors that need to be focused on to control eutrophication in Litopenaeus vannamei culture ponds.%2010年5-9月期间,对上海市奉贤区两个凡纳滨对虾(Litopenaeus vannamei)养殖场22个养殖池塘水体叶绿素a (Chl.a)、水温(T)、pH、溶解氧(DO)、透明度、溶解性总固体(TDS)、化学需氧量(CODMn)、氮磷营养元素等15项水质因子进行测定.取107组测定数据,进行描述性统计,利用主成分多元线性回归分析来模拟水质因子与凡纳滨对虾养殖塘叶绿素a含量的关系.根据主成分分析特征值大于1的原则,获得4个累计贡献率达到77.56％的潜变量,进一步的多元线性回归分析显示,潜变量F1对于叶绿素具有最大的相关性,建立了描述水质因子潜变量与Chl.a含量间相关性的模型:CChl.a=0.140+0.121·F1.研究表明,在各水质因子中,总磷(TP)与化学需氧量与Chl.a有极大的正相关:CChl.a=-0.052+0.005CODMn+0.188TP;且磷为塘内初级生产力的限制性因子.因此,有机物和磷含量是控制南美白对虾养殖池塘水体富营养化的关键因子.
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