Identification of surface water quality along the coast of Sanya, South China Sea

Two cruises were carried out in the representative months of the dry and wet seasons.During spring, sampling was carried out in May. During autumn, sampling was carried out in November.There are 27 stations where we sampled the surface layers waters.Nutrients (NH4-N, NO3-N, NO2-N and PO4-P), COD, total suspended matter (TSM) and Chl-awere tested according to “The specialties for marine monitoring” (GB17378.4-1998, China). Dissolved oxygen (DO) was determined with the method of Winkler titration. Surface water was filteredthrough 0.45μmfilter membrane and stored in a PVCbottle at 4 ℃ prior to analysis. Heavy metals (As, and Hg) were analyzed on Atomic fluorescence photometer . Heavy metals (Cu, Zn,Pb, and Cd)were analyzed onMultifunction polarography.