[Sediment record of phosphorus and the primary study of its bioavailability in Jiaozhou Bay sediments].

The geochemical characteristics of phosphorus forms in different grain size sediments, the influencing factors as well as the bioavailability of phosphorus in Jiaozhou Bay were investigated employing the sequential extraction method. The results showed that inorganic phosphorus was the dominant form of total phosphorus and organic phosphorus was only the minor part. The detrital carbonate-bound phosphorus was the largest part of total phosphorus. The grain size, organic carbon, temperature, pH and etc. are the main controlling factors of phosphorus in sediments. Except for Ca-P, most of other phosphorus forms contents increased as the grain size decreased. The bioavailability research showed that the bioavailable phosphorus was mainly the exchangeable phosphorus, phosphorus bound to Al and Fe and organic phosphorus. Moreover, the potential bioavailable phosphorus proportion in total phosphorus increased as the grain size decreased. The bioavailable phosphorus in different grain size sediments has positive correlationship with phytoplankton abundance and phosphate in overlying water.