[Forms and bioavailability of phosphorus in surface sediments from Sungo Bay]

Forms and bioavailability of phosphorus in the sediments of eight sampling sites from Sungo Bay were analyzed by means of sequential extraction method (SEDEX).

showed that: (1) The main form of total phosphorus (TP) in sediments was inorganic phosphorus (IP), which accounted for 73.33% and organic phosphorus (OP) was only the minor part. (2) Among different forms of inorganic phosphorus, calcium phosphorus (Ca-P) was the dominant forms, accounted for 45.22% of total phosphorus while organic phosphorus, adsorbed-phosphorus (Ads-P), iron-phosphorus (Fe-P) and detritus-phosphorus (Detr-P) was 26.67%, 9.92%, 4.74% and 13.46% respectively. (3) The correlation analysis among different phosphorus forms suggested that the concentrations and distribution of total phosphorus were mainly controlled by organic phosphorus (p < 0.05), while inorganic phosphorus was affected by calcium-phosphorus (p < 0.01). (4) Bioavailable phosphorus in sediments ranged from 358.05 microg/g to 448.39 microg/g and occupied 86.54% of the total phosphorus pool.