Scientists are trying to determine the chemical structure of toxins associated with Pfiesteria piscicida , a dinoflagellate believed to have caused major fish kills and human health problems along the U.S. East Coast. With structural data in hand, researchers will be in a better position to develop effective monitoring tests and study the toxins' mechanism of action. Lab tests and medical reports have indicated that contact with Pfiesteria -contaminated water or aerosols containing Pfiesteria toxin may cause human health effects that include disorientation, skin lesions, respiratory difficulties, cramps, diarrhea, and memory loss. As a result, some waterways have been closed in Maryland, and a hearing was held last week on Capitol Hill to discuss the Pfiesteria problem. Pfiesteria was discovered in 1988 by professor of aquatic medicine Edward J. Noga and a coworker at North Carolina State University College of Veterinary Medicine, Raleigh, and was named in honor of the late Lois Pfiester, an expert on din...