Abstract
In response to potential threats to human health and fish populations, six states along the east coast of the United States initiated monitoring programs related to Pfiesteria-like organisms in 1998. These actions were taken in the wake of toxic outbreaks of Pfiesteria piscicida Steidinger & Burkholder in Maryland during 1997 and previous outbreaks in North Carolina. The monitoring programs have two major purposes. The first, rapid response, is to ensure public safety by responding immediately to conditions that may indicate the presence of Pfiesteria or related organisms in a toxic state. The second, comprehensive assessment, is to provide a more complete understanding of where Pfiesteria-like organisms may become a threat, to understand what factors may stimulate their growth and toxicity, and to evaluate the impacts of these organisms upon fish and other aquatic life. In states where human health studies are being conducted, the data from both types of monitoring are used to provide information on environmental exposure. The three elements included in each monitoring program are identification of Pfiesteria-like organisms, water quality measurements, and assessments of fish health. Identification of Pfiesteria-like organisms is a particularly difficult element of the monitoring programs, as these small species cannot be definitively identified using light microscopy; newly applied molecular techniques, however, are starting to provide alternatives to traditional methods. State monitoring programs also offer many opportunities for collaborations with research initiatives targeting both environmental and human health issues related to Pfiesteria-like organisms.