Toxic Pfiesteria outbreak triggers federal-state research plan A series of river closings on Maryland's Chesapeake Bay this summer has accelerated federal and state efforts to protect the public from exposure to the toxic dinoflagellate, Pfiesteria piscicida. While scientists look for more funding for ecological research, others are calling for regulation of nutrient runoff from farmlands to prevent future Pfiesteria outbreaks. On Sept. 19, governors from Maryland, Virginia, Delaware, West Virginia, North Carolina, and Pennsylvania met with scientists and EPA Administrator Carol Browner to discuss the fish-killing alga. The states signed an agreement to share public health and environmental research results, notify one another of suspected outbreaks, work together for federal aid, and establish a technical team that will report by the end of this year on measures to evaluate the risks associated with Pfiesteria. Discovered in 1991 by JoAnn Burkholder, North Carolina State University, Pfiesteria is a predatory single-celled alga with 24 different life forms. The nontoxic life forms are ubiquitous in estuaries from Delaware to Alabama. But the alga can quickly change to a form that releases toxins that have killed billions of fish in North Carolina's shallow, nutrient-rich coastal waters. Burkholder's lab research has "demonstrated strong, direct links between high levels of nutrients and stimulation of Pfiesteria's toxic form," said ecologist Mike Hirshfield with the Chesapeake Bay Foundation. Hirshfield noted that field evidence for mis connection is strong but circumstantial. Don Boesch, president of the University of Maryland's Center for Environmental Science, cautioned that although some scientists speculate that Pfiesteria outbreaks are caused by overfertilization of farmland, the links are not yet proven. But a new thrust to Pfiesteria research was provided in August after scientists confirmed that the alga had killed 30,000 fish in Maryland's Pocomoke River and sickened fish in two other rivers on the eastern shore of the Chesapeake Bay. The state government responded quickly, closing the
three rivers and convening expert panels to investigate the environmental causes and human health effects of the outbreaks. Research on Pfiesteria appeared to get a further boost: Funding in an appropriations bill would give the Centers for Disease Control $7 million to address the human health effects of Pfiesteria toxins.
Scientists confirmed that the alga had killed 30,000 fish in Maryland's Pocomoke River and sickened fish in two other rivers on the eastern shore. Although at press time the bill had not been signed by President Clinton, congressional staffers said they were optimistic that the full $7 million would be included in the final bill. The funding appropriation came after a panel of Maryland doctors concluded in a report to the Maryland Department of Health and Mental Hygiene that exposure to Pfiesteria toxins caused human health problems that justified the closure of con-
taminated rivers. The doctors examined 29 patients who were exposed to natural waters during the fish kills. Symptoms included memory loss, shortness of breath, and skin rashes. At the Sept. 19 Governors' Summit, Browner reaffirmed federal cooperation in understanding and combating Pfiesteria's toxic forms. Hirshfield and others say that stringent regulations will be necessary to stop Pfiesteria outbreaks. Commenting on proposals from Maryland state legislators to require farmers to prepare nutrient management plans, Hirshfield said, "Mandatory planning is not sufficient to address the problem of nutrient pollution. We need more aggressive measures, including wedand restoration and upgrading of sewage treatment plants." At the Governors' Summit, William C. Baker, president of the Chesapeake Bay Foundation, called on Browner to set federal limits on nutrients in the nation's waters. He also called for a moratorium on new poultry and hog farms in the Chesapeake Bay watershed until federal nutrient limits are in place. Bill Satterfield of Delmarva Poultry Industry, Inc., said, "Until scientific evidence is presented, there is no reason to blame this industry." —JANET PELLEY
NUCLEAR WASTE Plutonium discovery threatens Yucca repository The discovery of plutonium in Nevada groundwater has prompted calls for an investigation into the safety of the proposed U.S. high-level nuclear waste repository at Yucca Mountain. Presenting their findings at an American Chemical Society meeting Sept. 10, researchers from two Department of Energy (DOE) laboratories offered evidence that plutonium had migrated a mile from the site of a 1969 underground nuclear weapons test in the Nevada desert. "This is the first time we've seen plutonium transported in groundwater," said Annie Kersting, a chemist at Lawrence Livermore National Laboratory. The plutonium was discovered in a monitoring well on the Nevada Test Site by scientists from the Lawrence Livermore and Los Alamos national laboratories. The potential for groundwater contamination from a nuclear repository has been one of the foremost concerns since DOE began its assessment of the Nevada site. "I believe this is another nail in the coffin of the Yucca Mountain project," said Sen. Richard Bryan (D). Bryan and Sen. Harry Reid (D) have asked DOE and the General Accounting Office to investigate the plutonium migration and the potential for similar contamination at the Yucca Mountain site. The findings will not alter DOE's scientific assessment of the Yucca Mountain site because "studying the hydrology has always been an integral part of our studies," said DOE spokesman Erik Olds. —RAE TYSON
VOL. 31, NO. 11, 1997 /ENVIRONMENTAL SCIENCES TECHNOLOGY/ NEWS • 5 0 3 A
