Dr. JoAnn Burkholder, director of North Carolina State University's Center for Applied Aquatic Ecology, presented the results of the new study Tuesday at the 10th International Conference on Harmful Algae in St. Petersburg, Fla. The findings are significant because they reconfirm a decade of research showing that Pfiesteria is a dangerous toxic organism.
Last summer's papers had been critical of work by Burkholder and other scientists who discovered Pfiesteria and described its life cycle and toxic impacts on fish and mammals. However, the dissenting scientists' work was based primarily on research with one strain. In the new study three laboratories, assisted in toxin analysis by a fourth "blind" lab, have shown that this allegedly nontoxic strain does produce toxin after all. Burkholder said that their team's results differed because they grew the culture under conditions that allowed it to express toxicity.
"I hope these findings finally help set the record straight by addressing the widespread misinformation about this issue during the past few months," Burkholder said. "Growing these cultures is very complex and difficult work. We are entirely confident that the strain we have tested, taken from the very same culture they used, is toxic and dangerous."
Populations or strains of Pfiesteria, like other toxic algae, are known to vary in toxicity. There are strains that can kill fish with toxin and benign strains that cannot. More than 50 peer-reviewed science articles have been published about toxic Pfiesteria, in cross-confirmed research based on more than 400 toxic strains and 200 nontoxic strains.