Given the heightened concern, though, a team of scientists from Virginia and Maryland will try to learn how widespread Pfiesteria may be in the Bay. They plan to look for the algae in archived samples that have been collected throughout the Chesapeake the last 13 years as part of the Bay Program's water-quality monitoring effort. In addition, they may examine areas where algae blooms have been reported in the past to see if they can find dormant stages of Pfiesteria in the sediment. He and others suspect that the species may have been in many parts of the Bay for years, but has never been identified. The reason, they say, is that the species has a complex life cycle with more than 20 distinctive stages.
Identification requires powerful electron microscopes and training.
Burkholder's research indicates that Pfiesteria spends most of its life dormant in microscopic cysts on the bottom of estuaries and brackish portions of rivers. They transform into active cells and fill the water in huge numbers. They release a toxin that paralyzes the fish's nervous system, causing it to gasp for breath at the surface. Eventually, the fish suffocates, and the Pfiesteria begin consuming the flesh, leaving lesions that look like open sores on the dead fish. Soon, the algae transform into different life stages, before returning to cysts at the bottom, sometimes within a matter of hours.