Comparative study of phosphorus strategies of three typical harmful algae in Chinese coastal waters

A series of batch culture experiments were carried out to compare the specific eco-physiological responses of three typical harmful algae of Chinese coastal waters to environmental phosphorus (P) variations. Results showed that Skeletonema costatum, when compared with Prorocentrum donghaiense or Alexandrium catenella, was a better growth strategist in nutrient-rich condition. Although S. costatum had a greater advantage in phosphate affinity and could save more internal P, it also had a higher P demand for growth and it used up all its resources to sustain a high growth rate. The growth of S. costatum collapsed soon after phosphate depletion. P. donghaiense and A. catenella, with lower growth rates, could survive well under P-limited conditions. With higher affinities for dissolved organic phosphorus (DOP), P. donghaiense and A. catenella might likely make good use of the metabolized DOP in the water after the collapse of S. costatum blooms to sustain their growth.