Response of Harmful Algal Blooms to Environmental Changes in Daya Bay, China

the ratio of TIN/P increased also, with a peak value (18.28) in 1999.Organic contaminants have also been relatively high in recent years in Daya Bay.The seasonal extension of HAB was found to be connected partially with increased water temperature resulting from the thermal discharge of nuclear power stations.Yearly mean water surface temperature (WST) increased over the past two decades.Monthly mean WST also increased after the Daya Bay nuclear power station commenced operating in 1994, ranging from 0.2 to 2.7°C.There were about 14 algal species recorded to have caused HABs frequently in Daya Bay, such as Scrippsiella trochoidea.The number of HAB species increased in the second decade (1994 -2004).A warm-water favoring species Peridinium quinquecorne caused a bloom in May 1999.This was the first recorded time of this species blooming in China.These changes are associated with increases in cage aquaculture, contaminants discharged from industrial and agricultural activities, and thermal discharge from the nuclear power stations in Daya Bay.