There have been doubts about claims by researcher JoAnn Burkholder that a toxic marine microbe killed fish along the East Coast.
Burkholder now has something to back up her claims.
The National Oceanic and Atmospheric Administration agency says two species of the microbes called Pfiesteria can transform into toxic organisms that cause fish kills.
The microbe shut down some North Carolina and Maryland waters in the mid-1990s. Burkholder helped discover the organism in state waters in 1989. But her work was questioned by others who doubted that Pfiesteria spewed poison to attack estuarine fish.
After nine years of study, NOAA and chemist Peter Moeller identified the venom.
Environmentalists praised Burkholder's work despite doubts raised by other scientists and public health officials. As for the latest findings, Burkholder says the past nine to 10 years have been difficult, but the finding makes it a great day.