Effects of Thermal Discharge from a Coastal Power Plant on Phytoplankton in Zhanjiang Bay

Abstract

Effects of thermal discharge from a coastal power plant on phytoplankton community were determined in subtropical Zhanjiang Bay. Two sampling transects were chosen up and down the Zhanjiang Plant in the Zhanjiang Bay, Nine stations were located along the two transects, which were divided into four zones. Monthly boat cruises were undertaken in the bay at spring up here, tide ebb slack, neap rise open and neap tide ebb slack respectively, during the period April-October 2012. Species diversity (H') showed a distinct increasing gradient from the most thermally polluted zone to the healthy zone. The more distinct gradient occurred at spring tide. Species diversity fluctuated during April-October 2011 and four sampling tide times with no visible patterns. Evenness showed indistinct gradient from the heated water source to the control zone, and fluctuated during April-October 2011 and four sampling tide times with no visible patterns. Species richness, cell count and Chl a concentration at mixed and healthy zones were significantly higher than that at heated zones, with the maximum value recorded at mixed zone, and showed seasonal and tidal changes with no obvious pattern.