A team of researchers from the Hollings Marine Laboratory in Charleston, S.C., has uncovered a subtle chemical pathway by which a normally inoffensive algae, Pfiesteria piscicida, can suddenly start producing a lethal toxin. The discovery, reported last week in Environmental Science and Technology,* could resolve a long-standing mystery surrounding occasional mass fish kills on the East Coast.
Pfiesteria has been implicated for years in a series of otherwise unexplained episodes of mass fish death throughout its range from roughly Delaware to Alabama, particularly in the Neuse River in North Carolina and the Chesapeake Bay. The single-cell organism can experience explosive growth resulting in algae blooms in coastal waters. While it has been suspected not only in fish kills but in incidents of human memory loss and other environmental and health-related effects, no one has ever conclusively identified the actual mechanism. Attempts to grow lethal Pfiesteria in the laboratory have had inconsistent results.
The Hollings Marine Laboratory is a joint institution of the National Oceanic and Atmospheric Administration (NOAA), the National Institute of Standards and Technology (NIST), the South Carolina Department of Natural Resources, the College of Charleston, and the Medical University of South Carolina (MUSC). Lead researcher Peter Moeller of NOAA suspected that the presence or absence of heavy metals might be the missing factor accounting for Pfiesteria's lethality, and put together a multidisciplinary research team to identify the actual toxin and the conditions under which it is produced.
The work was complicated by the fact that the suspect toxin turns out to be highly unstable, decomposing rapidly once it's activated. Chemists from NIST and MUSC used an array of advanced spectroscopic techniques to determine that the toxin is characterized by the presence of copper-sulfur complexes. "NIST saved the day," Moeller said, "because we w
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Contact: Michael Baum
michael.baum@nist.gov
301-975-2763
National Institute of Standards and Technology (NIST)
19-Jan-2007