Watch out for killer algae: years of dumping hog wastes into North Carolina rivers has created a monster.

Imagine a microscopic marine predator which can spend years at a time without food, but which, when conditions are favorable, suddenly emerges from the sediment, changes shape and kills millions of fish after stunning them with a poison so powerful it can cause immuno-suppression in humans. Find it hard to believe? Go tell it to Dr. JoAnn Burkholder.

Burkholder, a freshwater botanist at North Carolina State University, is the person who first discovered and described the phytoplankton species Pfiesteria Piscidia when it began killing fish in a university aquarium several years ago. And she's used to people not believing her.

According to Burkholder, Pfiesteria spends much of its life as harmless-looking, microscopic cysts in the sediment. But introduce large numbers of fish and, under the right conditions, it undergoes a transformation out of a science-fiction movie. In minutes, the cysts turn into what Burkholder calls "toxic flagellated vegetative cells" and propel themselves towards the fish. They stun the fish by unleashing a powerful toxin and then, after the fish die, transform themselves into large amoebae and eat the carcasses. As they're feasting on the fish, they are photosynthesizing, using chloroplasts they've "stolen" from algae they've eaten previously. The feeding frenzy over, they revert to their cyst form and return to the sediment.

Phytoplankton aren't supposed to behave like that. In fact, no form of life is supposed to behave like that. But Burkholder, more than anyone, is acutely aware of just how real Pfiesteria and its toxins really are.

One day early in her research, after spending three hours in her laboratory's small environmental chamber, gently pouring culture containing the algae into a flask, Burkholder became steadily disoriented; she began to suffer from stomach cramps and underwent an asthma attack. Her eyes became so bloodshot that for a couple of days she found it difficult to see. For eight days, she lost her short-term memory. More recently, her colleague, Dr. Howard Glasgow, received such heavy exposure to the toxin that he was hospitalized and is no longer able to work directly with the algae for fear of further exposure.

The university now rates Burkholder's work a Level 2 biohazard, slightly below that of AIDS and on par with rabies. Several years later, Burkholder regularly suffers from bronchitis and pneumonia, and can no longer exercise strenuously without suffering further relapses; she now approaches her subject only when covered from head to toe with protective laboratory clothing and wearing a full-face-mask respirator.

Burkholder believes that Pfiesteria, or species very similar, are lurking in the sediment all over the globe, and have been for millions of years. Now, however, conditions are shifting increasingly in their favor.

Pfiesteria flourish in the presence of phosphates, which are naturally concentrated in the North Carolina region. Over the last five years North Carolina's hog industry has grown from the 17th-biggest to the second-largest in the country, generating an attendant increase in nutrient-rich effluent spills. North Carolina is, by some estimates, the number one state in the country in toxic discharges into its rivers and ranks either 43rd or 47th on spending on environmental programs.

Burkholder has regularly warned that unless serious pollution prevention measures were taken, North Carolina could experience a serious Pfiesteria bloom, with accompanying human health and environmental consequences. Last summer and fall, that prophecy came true.

A period of heavy rains in July caused larger-than-usual soil and nutrient run-offs into the Neuse River. Newspaper headlines screamed, "Swine Sewage Sweeps Downstream" and "25 Million Gallons Lost at Hog Farm." Fish began dying: 4,000 within the first week or two and between seven and 11 million after four months. People living along the riverside began complaining of festering sores, weight loss and stomach cramps. Pfiesteria was found in the water.

State officials, with one eye on North Carolina's tourist industry and another on the mining and hog farming lobbies (Governor Jim Hunt is the biggest recipient of political contributions from the state's largest pig farmer) refused to accept there was a problem, or to issue a health warning. One spokesman accused Burkholder of turning "Pfiesteria into hysteria." On-slow County Commissioner Sam Hewitt called on state officials to "silence" Burkholder and her fellow scientists, adding that he would "like to take a rubber hose to some of them."

Only when fish vendors across the country began returning North Carolina fish, for fear that it was somehow toxic, did officials close a 17-mile stretch of the Neuse River. By late November, a spokesman for North Carolina's Department of the Environment, Health and Natural Resources (DEHNR) told E that Pfiesteria did indeed appear to be the primary agent of the fish deaths, and that the state was looking again at the problem of hog effluent.

The Pfiesteria outbreak ended in late October. But Pfiesteria hasn't gone away, merely returned to the sediment. And although North Carolina may be doing the best it can to create those conditions, Pfiesteria need not necessarily show up there next. So far, it been found as far south as the Gulf of Mexico and as far north as Delaware Bay.

According to Dr. Ted Smayda of the University of Rhode Island, "The evidence certainly does suggest that by putting more and more effluent into coastal waters, we are helping create a comfortable environment for these creatures. We can certainly reduce the amount of nutrients we place into the water. It's the prudent, conservative thing to do."

CONTACT: Global Oceans Watch, 1727 Massachusetts Avenue NW, #716, Washington, DC 20036/(202)3828.