Heterosigma Akashiwo And Alexandrium Tamarense Nutritional Requirements And The Effects On Fish Toxicity

This paper mainly studied effects of nutrition factors on the growth of Heterosigma akashiwo and Alexandrium tamarense and the toxicity and the toxicity mechanism of these two kinds of toxic algae on the fish. This research has very important meaning to the evaluation of the harmful algal blooms on the marine biology resource, reducing the losing of fishery production, avoiding the harm to human's health. This paper mainly discussed as followings:1 Reasearch of the effects of nitrogen, phosphorus and iron on the growth of Heterosigma akashiwo and Alexandrium tamarenseAccording to the one-factor experiment of the effects of nitrogen and phosphorus on the growth of Heterosigma akashiwo, the optimum concentration range of nitrogen and phosphorus for the Heterosigma akashiwo were 882~3528umol/L and 72.4 ?289.6umol/L respectively; The best ratio of N/P which adapted to the growth of the Heterosigma akashiwo was 24.According to the one-factor experiment of the effects of iron on the growth of Alexandrium tamarense, the optimum concentration range of iron for the Alexandrium tamarense was 0~5.8umol/L(the iron concentration of the sea water was 20.43ug/L); The orthogonal test of the three factors of nitrogen, phosphorous and ironn showed that the optimal concentrations of the three nutrients were as follows: 441umol/L, 18.1umol/L, 5.8umol/L. NaHPO was the dominant factor of the nitrogen, phosphorus and iron.2 The effect of algal culture and different fractions of Heterosigma akashiwo and Alexandrium tamarense on the Paralichthys olivaceus in different growth phases {Paralichthys olivaceus larvae and juvenile}The algal culture of Heterosigma akashiwo and Alexandrium tamarense had the remarkable harmful influence on the Paralichthys olivaceus of it's different growth phases (P<0.05), but the toxicity of algal culture acting on the early development was the highest. The ways leading fishery organism of the two kinds of algal to toxicity are not only by eating algal causing the accumulation in body of algal toxin, but the...