NMFS NUMBER: 92-WO-021
Toxic Dinoflagellate Affecting Cultured and Wild Estuarine
North Carolina State University
February 6, 1997
National Marine Fisheries Service, National Program Office,
1315 East-West Highway, Silver Spring, MD 20910.
PHONE: (301) 713-2358
The goal of
the project was to characterize the ecological distribution,
algal physiology, disease effects, and toxin of a new
toxic dinoflagellate, Pfisteria piscicida, recently
discovered in the Albemarle-Pamlico Estuary. The
organism is highly toxic and has been implicated in several
major fish kills. The project was temporarily halted
until a more rigid safety plan for handling the toxic
dinoflagellate in the laboratory was developed.
A field sampling survey for Pfisteria piscicida
was conducted in the Albemarle-Pamlico Estuary. Collaborators
also identified this organism in the Delaware Bay and
Chesapeake Bay Estuaries. The optimal salinity for toxic
blooms was determined to be 15 ppt, with a range from
nearly freshwater to 35 ppt. Fish were exposed
to a standardized concentration of the algae and examined.
A variety of adverse effects were observed in toxin-exposed
fish, including massive skin damage, edema, and hematological
changes. The toxin was successfully extracted from seawater
and the extract was demonstrated to kill fish in a bioassay.