网箱养殖对东湖沉积物有机质含量以及磷的酶促水解与吸附行为的影响

东湖养殖非鱼（Oreochromis niloticus）的网箱下沉积物中有机质和可酶解磷（PHP）含量以及碱性磷酸酶活性（APA）均显示增高，间隙水中的PHP较低，而APA与正磷酸盐的浓度均高，这种现象在垂直与水平两个尺度上均有体现，故由有机物的富集到正磷酸盐的剧增可能受控于酶学机制。Langmuir单分子等温度吸附模型的分析结果表明网箱下表层沉积物的最大吸附量明显较高，面吸附强度明显降低，此亦为正磷酸盐相应剧增的另一重要原因。不同深度间隙水中APA的动力学行为表现出明显的季节性。

Influence of cage-culture on the contents of organic matter and enzymatic hydrolysis as well as adsorption behavior of phosphorus in sediments of Lake Donghu

The sediments immediately under the cage once rearing Oreochromis niloticus showed significantly higher content s of organic matter ( OM) and phosphatase hydrolyzable phosphorus ( PHP) , and alkaline phosophatase act ivity ( APA) as well. In interstitial water, both APA and orthoposphate ( o-P) concentrations were signif icantly higher, while PHP was significantly lower, at vertical and horizontal scales. These results suggested that the enhancement of o-P release from sediment, resulted f rom the enrichment of OM, might be controlled by an enzymatical mechanism. The Langmuir isotherm approach revealed that, in interstitial water under the cage, sorption capacity was signif icantly higher, while the corresponding sorption strength was signif icant ly lower in the upper layers, which lends an additional explanation to the enhancement of o-P release in the sediments as affected by the cage culture. A remarkably seasonal variation in vertical patterns of kinetics of APA was observed in interstitial water.