A North Carolina State University scientist’s theory about what turned a marine microbe into a toxic organism that caused vast fish kills in the 1990s was largely vindicated this week, with the release of a nine-year study that said the “cell from hell,” as it’s sometimes called, can spew out poisons that kill fish, according to The News & Observer, a North Carolina newspaper. The scientist, JoAnn B. Burkholder, helped discover the organism, a dinoflagellate called Pfiesteria, which was blamed for the death of billions of fish in Maryland and North Carolina waters — and for causing memory problems in fishermen who encountered it.

At the center of the bitter scientific dispute was whether Pfiesteria could kill fish by emitting toxins, as Ms. Burkholder said, or could kill only by directly attaching itself to its victims, as critics claimed. The new study, conducted by the National Oceanic and Atmospheric Administration, said the organism could kill in both ways.

The Chronicle reported on Ms. Burkholder’s controversial work to decipher the mysterious microbe’s life cycle, as well as the sharp criticism she drew for her theories and approach, in feature articles published in 1998 and 2002.