Studies On The Growth Of Prorocentrum Donghaiense And Alexandrium Tamarense Under Different Environmental Factor And The Interspecific Competition

In recent years, along with the economic extension, harmful algal blooms (HAB) broke out frequently in East China Sea (ECS), which has become the most serious HAB area of the Chinese seas. The major causative algae is Prorocentrum donghaiense, and sometimes with Alexandrium tamarense. But little is understood of the forming mechanism of these blooms. In this paper, we chosed these two species to study the effects of irradiance,temperature and salinity on their growth behavior, the effects of nutrition on the interspecific competition, as well as the competitive mechanism of the two algae species. The main results and conclusions are listed as follows:Firstly, three-factor-experiment was used to study the combined effects of irradiance, temperature and salinity on the growth of P.donghaiense and A. tamarense. The results showed that growth of P.donghaidense was significantly different under irradiance of 100,55,30 and 15μmol·m-2·s-1, temperatures of 10,13,17,20, 23 and 26℃, and salinities of 16,21,25,28, 32 and 35. The growth of A.tamarense was significantly affected by irradiance and temperature, but not salinity. The optimal growth condition of P.donghaiense is temperature 23-26℃,salinity 28-35 and irradiance 30-100μmol.m^-2.s^-1., while for A. tamarense is from 23-26℃, 25-35 and 55-100μmol.m^-2.s^-1 resepectively.Secondly, we studied the effects of limited phosphate on the interspecific competition of P.donghaiense and A.tamarense at different initial cell densities. As a...