Abstract: A laboratory experiment with orthogonal design was conducted to study the effects of factors salinity, temperature, and light intensity on the growth and toxin production of Chattonella marina. Three levels of salinity (22, 33, and 45), temperature (20 ℃, 25 ℃, and 30 ℃) and light intensity (2000, 3000, and 4500 lx) were installed. In all treatments, the three factors had no significant effects on the growth of C. marina, but salinity significantly affected the toxin production of C. marina. Under salinity 45, temperature 30 ℃ and light intensity 2000 lx, C. marina had the maximal growth rate; under salinity 22, temperature 20 ℃ and light intensity 4500 lx, the toxin production of C. marina was the maximal. Low salinity was not favorable to the C. marina growth but favorable to its haemolytic toxin production. When the growth of C. marina was limited, its haemolytic toxin production increased.

Key words: acidic soil, heavy metal, amendment,  Hibiscus cannabinus, reclamation.