Mechanisms of phosphorus released from the sediment–water interface in Xiamen Bay, Fujian, China

Abstract

The concentrations of DRP (dissolved reactive phosphorus) in the estuary harbour waters along the coast of China are generally low, and the N/P ratios are much higher than the Redfield ratio. From Dalian Bay to the Zhujiang Estuary these ratios are as high as n·10–n·100. Field observations at the Jiulong Estuary and Xiamen Harbour in Fujian in recent years revealed that the high values of N/P ratios are 50-80 during April–October and 90-200 during November–March, respectively. A red tide of Skeletonema costatum developed in Dalian Bay waters in the summer of 1988, where the N/P ratio was increased rapidly from 50 to 190, and reached as high a value as 340 at the end of the rampant algal propagation. This clearly indicates that phosphorus plays an important role in controlling eutrophication and red tide in China's marine coastal waters.