Study On The Removal Of Symbiotic Phaeocystis And Heterosigma With Isothiazolone

Red tides have adverse impacts on ocean environment,fish culture,ocean tourism and the development of economy,moreover it may threaten public health.HABs have aroused generally attention and let to extensive researches to mitigate the blooms.There are so many methods to remove the algae from the water,however,in the past,most of these methods were focused on single one algae.Compared to the condition simulated in laboratory,the ocean environment is more complex,there are unavoidable other kinds of algae growing with the preponderant one.So investigate algicidal effects of algicide to the mix-cultured algae have guidance sense in pracitical prevention and cure of red tides.This paper chose two typical kinds of HAB species P. globosa and H. akashiwo to investigate their symbiotic relationship by mixed culture way.and ulteriorly investigated their action mechanism.And chose isothiazolone to be the algicide,investigate it's algicidal effect to mix-cultured P. globosa and H. akashiwo .During the experiment measure the concentration of the algicide by High Performance Liquid Chromatography method everyday, in order to know the rudiment of the algicide in the culture. And study the change of the chlorphyl-a in the algae cells in order to token the total algicedal efficiency to the mix-cultured algae.The conclusion show: When mix-cultured,P. globosa can restrain the growth of H. akashiwo by poisonous secretion;However,through direct contact with algae colony, the poisonous substance on H. akashiwo cells' surface may accelerate the cracking of P. globosa colony, so the cell of P. globosa increased;When the concentration of algicide is 1.2 mg/L,48 hours later the algicidal efficiency to commensal P. globosa and H. akashiwo which have been mix cultured for 5 days can reach 98%.And under the apart culture condition,when the concentration is 0.8 mg/L it can already get the same algicidal efficiency,it means the existence of other kinds of algae have adverse impact to algicidal efficency.During the experiment,the concentration of the isothiazolone minished gradually,it means isothiazolone can...