Red Tide Occurrence and Eutrophication Status in the Red Tide Monitoring Area of Bohai Bay in 2012

Analysis of the changes of water quality during the hydrological and meteorological factors,physicochemical factors and phytoplankton cells during the red tide occurred in 2012,hydrological and meteorological factors and seawater physicochemical factors was the driving force for the occurrence of red tide,induce the occurrence of red tide,eutrophic seawater promoted the growth of algae,resulting in red tide outbreak.Analysis of the red tide monitoring area of eutrophication from 2009 to 2012,red tide monitoring area were in the eutrophication in the past four years,and the eutrophication degree increased,mainly limiting factor of phytoplankton growth and reproduction was the active phosphate,by2012,eutrophic state was gradually from phosphorus limitation to nitrogen and phosphorus were not restricted.