(1) 中国科学院烟台海岸带研究所

Organic phosphorus is an important source of soluble phosphorus via enzyme hydrolysis. It is of great significance to study the bioavailability of organic phosphorus in order to fully understand the mechanism of lake eutrophication. The surface sediments have been collected from a eutrophic coastal lagoon-Swan Lake of Rongcheng. The enzymatic hydrolysis has been used to analyze the bioavailability of organic phosphorus and its temporal and spatial variation. The results show that the contents of organic phosphorus in Swan Lake was 107.9~ 161.9 mg·kg~(-1) with mean content of 125.3 mg·kg~(-1). The content of enzymatic hydrolysis organic phosphorus (EHP) was 21.8~ 100.3 mg·kg~(-1) with mean content of 53.2 mg·kg~(-1) which accounted for 26%~ 56% of the organic phosphorus. The bioavaiability of EHP followed the order of phytic-P (21.5 mg·kg~(-1)) Diester-P(20.7 mg·kg~(-1)) >Monoester-P(14.1 mg·kg~(-1)). The organic phosphorus was concentrated in the estuary and the center lake,which was attributed to the different phosphorus sources,the distribution of aquatic animals and algae and the sediments grain size. Results of The correlation analysis suggest that organic phosphorus was mainly combined with metal oxides (Al、Fe、Mg、Ca) which indicates that the content and the variation of metal oxides would control the hydrolysis and bioavilability of organic phosphorus. In conclusion,the hydrolysis of organic phosphorus played an important role in the source of soluble phosphorus and to a certain extent caused the eutrophication of Swan lake. As a result,much effort should be made on organic phosphorus in the amendments of water pollution.