Removal of different species of red tide organisms with an effective clay-complex system

SONG Xiuxian 1,2, YU Zhiming 1, GAO Yonghui 1( 1Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071,China, 2Graduate School of the Chinese Academy of Sciences,Beijing 100039,China)

Clay-complex system, Red tide organisms, Removal efficiency,Penaeus japonicus,Toxic test

An effective clay-complex system was composed on the base of clay by added other two components A and B. Different red tide species, such as Scrippsiella trochoidea, Amphidinium carterae and Heterosigma akashiwo, were coagulated by this clay-complex system,and the optimum conditions for removal red tide organisms were obtained by means of orthogonal test. The results showed that clay was the most important factors in this complex system to coagulate these three organisms. The removal efficiency on three species was in order of Scrippsiella trochoidea > Amphidinium carterae > Heterosigma akashiwo. At the same time, a preliminary study of mortality rate on Penaeus japonicus (length between 1.0 to 1.5cm) was conducted with this system,and the result of toxic test revealed that the mortality of aquiculture shrimp in control group (nothing added) reached to 80% after 96h, however,while that of other three groups which added clay and other two components A and B, was below 40%.Thus,it implied that the addition of clay would be harmless to Penaeus japonicas. Furthermore, suitable concentration of components A and B was not harmful for the aquiculture shrimp, but increased the removal efficiency of red tide organisms. The preliminary results showed that this clay-complex system would be available in the removal of red tide organisms in filed.