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Pfiesteria Facts | Health Effects on Humans and Wildlife What is Pfiesteria? Pfiesteria piscicida is a microbe, a one-celled organism. Pfiesteria was first identified in 1991 by researchers at North Carolina State University. What's so bad about Pfiesteria? Pfiesteria normally exists in a harmless state, but it can change into a form that may give off toxins that can kill fish and other aquatic life. Scientist have not yet determined what causes Pfiesteria to turn toxic. Pfiesteria causes lesions in fish and has caused massive fish kills in rivers, including the Neuse River, where a 1995 outbreak killed 14 million fish and closed 364,000 acres of shellfish beds. In Maryland, scientists have found fish with lesions similar to those caused by Pfiesteria in four rivers: the Pocomoke River, the Chicamacomico River and a branch of the Manokin River. Fish in Virginia's Rappahannock River have also been found with lesions. In Maryland, stretches of the three affected rivers have been closed. In the case of the Pocomoke river, the closure was ordered due to public health, not environmental concerns. Fish affected have been both menhaden (not human food, used for oils, etc.) and sport fish species like striped bass. So far, there are no indications of harm to birds and other species, but concerns about human health for those exposed to water bodies remain. Preliminary work done by physicians from Johns Hopkins University indicates ill effects in people who have had contact with water colonized by Pfiesteria. In North Carolina, physicians have reported skin ailments, memory loss and asthma-like symptoms, among other complaints, in more than 100 patients. It is not yet clear whether the harmful agent is only water-borne or may be transmitted by inhalation. Why are the Pfiesteria outbreaks happening? Nobody is sure -- at least not yet. Pfiesteria seems to favor waters high in "nutrients" (nitrogen, phosphorus), but outbreaks aren't necessarily imminent in water-bodies with high nutrient levels. In addition, although the microbe usually grows in warmer waters, outbreaks have occurred in October and November, in cooler weather. " Activation" of the microbe often takes place in shallow water with poor circulation and with high concentrations of fish. However, "activation" has occurred in other water environments, too. Though the causes of Pfiesteria outbreaks are not fully understood, in several cases scientists have linked the problem to polluted run-off as one factor. Polluted run-off -- a scourge that affects many of our nation's waterways -- comes from many sources. Programs to protect our water from run-off aren't always strong enough or adequately enforced. In some states, run-off can be traced in part to high-density livestock raising operations. For example, in the tidewater areas of Maryland, Delaware and Virginia (known as the Del-Mar-Va peninsula), farmers raise 600 million chickens, with about 24 pounds of waste per bird. Although many operators are diligent about waste control, too much nitrogen leaves the land and ends up in the water, creating an environment where Pfiesteria can thrive. In North Carolina, industrial-sized hog farms may pose the same problem. North Carolina's hog population is approaching 10 million. And in 1995, 25 million gallons of pig manure -- more than twice the volume of the Exxon Valdez spill -- burst from a ruptured manure-storage facility into the New River. Agriculture does contribute, but there are a myriad of other sources of "nutrients" or polluted run-off into the waterways. For example, fertilizers applied on home gardens and golf courses, auto emissions of nitrogen, and industries that refine oil or burn coal can also contribute. Pfiesteria is front-page news in areas along the Atlantic Coast, but waterways choked by polluted run-off are problems that are national in scope. For example, along the Gulf Coast, citizens are growing more and more alarmed at the so-called Dead Zone, an area roughly the size of the state of Massachusetts, where low-oxygen waters make fish-kills commonplace, thereby devastating the commercial fishing and shrimping industries. What can we do to stop the outbreaks? The recent outbreaks of Pfiesteria only heighten Americans' concern about clean water, a concern that hasn't diminished in the 25 years since the Clean Water Act was signed. Although we've made strides in cutting pollution from industries, more needs to be done to keep waterways safe from polluted run-off. Livestock farmers need to handle wastes in ways that protect our water, but it's everybody's responsibility to reduce pollution. Pollution prevention is the key. There are many sources of pollution burdening our rivers and coastal waters -- from failing septic systems, to inadequate wastewater treatment plants, to boating and navigation, as well as agriculture and airborne pollution. Restoring overall health to our rivers, estuaries and bays will require concerted efforts to address those sources combined with protecting and restoring the wetlands and forested buffers that play such critical roles in filtering out pollutants, preventing them from flowing into our waterways. That's how we can help stop Pfiesteria in its tracks. If we protect wetlands and forests near our waterways -- instead of paving and developing open spaces -- we'll help keep our waters safe. Health Effects of Pfiesteria The recent outbreaks of the Pfiesteria microbe have prompted great concern among citizens, particularly with regard to the health effects. Although scientists have not yet conclusively determined what causes outbreaks of the deadly form, the health impacts on wildlife have been quite clear. The toxic forms of Pfiesteria often attack fish, such as menhaden, causing the formation of skin lesions and ultimately death. Scientists believe that, in addition to severely impacting wildlife, the outbreaks may pose a threat to public health. Preliminary research investigating the human health effects reveals that the toxic form may lead to skin ailments, short-term memory loss, and asthma-like symptoms. Congress approved legislation on November 13th which allocates $5 million per year to universities researching Pfiesteria, and $13 million for research efforts at the Environmental Protection Agency, the Centers for Disease Control, and the National Oceanic and Atmospheric Administration. The agencies will study the human health effects more closely. Likewise, scientists at North Carolina University will pursue research to determine what initiates the toxic Pfiesteria forms and to understand more clearly how the toxins interact with humans. Human Health Impacts
Researchers studying the microbe are not the only ones who have suffered serious health effects from exposure to the toxins of Pfiesteria. The Maryland Department of Health and Mental Hygiene revealed on November 14th that 37 cases were reported in the Chesapeake Bay area of people suffering the symptoms of memory loss, skin rashes and lesions, and bouts of vomiting. Some of the affected persons were state officials taking water samples, boatsmen, fishermen, and a jet skier who came in contact with the water during a Pfiesteria outbreak. Wildlife Health Impacts A great deal of attention has been devoted to the wildlife health effects, particularly the fish illnesses and lesions. Some fish have experienced relatively mild lesions to the Pfiesteria attacks, while other fish populations have suffered more severe lesions. These links to the University System of Maryland Pfiesteria pages provide photographs and descriptions of the range of impacts on fish populations. (Photo from the University of Maryland). Up to Top HOME | Email Signup | About Us | Contact Us | Terms of Use |
Researchers at North Carolina State University have personally experienced the harmful human health effects related to the toxic Pfiesteria.