Yesterday a University of North Carolina marine biologist presented a rare bit of common sense related to Pfiesteria piscicida [fiss-TEER-ee-uh piss-ki-SEED-uh]. That’s the pesky microorganism that environmental groups like Robert F. Kennedy Jr.’s Waterkeeper Alliance have long blamed for massive fish kills and harm to human health. Wayne Litaker, whose credentials include stints with the National Marine Fisheries Service and the National Ocean Service, presented research that just might put an end to all the Pfiesteria hysteria.

The published abstract of Litaker’s talk includes a startling find: it appears the microbes that actually killed fish and made some people sick weren’t Pfiesteriae at all. They were ordinary amoebas. “Amoebae identical to those reported in the original [Pfiesteria] life cycle,” he says, “were present in the tanks where Pfiesteria was killing fish, but these turned out to be contaminants brought in by the fish and were present even before fish were exposed [to Pfiesteria].”

And that’s not all — “the tanks from which the putative toxin for Pfiesteria has been isolated,” Litaker has concluded, “are highly contaminated with bacteria, amoebae, other protozoans and fungi.”

The final nail in the coffin: “Pfiesteria co-occurs in estuaries with numerous look-alike species. Not being able to reliably identify Pfiesteria meant there was no way to accurately assess any public health threat posed by this species.”

Translation: the much-discussed experiments, in which Pfiesteria was blamed for causing toxic lesions on fish and humans, were all wet. The tanks were so dirty that no one really knows what caused the observed reactions. And in reality, scientists can’t even distinguish Pfiesteria piscicida from its many doppelgangers.

The Waterkeeper Alliance, the Natural Resources Defense Council, the Sierra Club, and Environmental Defense all contend that the Pfiesteria “crisis” stemmed from industrial livestock farming practices. Kennedy, a notorious opponent of America’s hog farmers, wrote in a Newsweek opinion piece a few years ago that Pfiesteria killed “a billion [fish] in one 1991 incident,” “causes brain damage and respiratory illness in humans,” and had already “sickened dozens of people, including fisherman, swimmers and state workers.”

Now the real science indicates that he was either naive or just guessing. What a shocker.