Real-Time PCR Monitoring of Estuarine Water Samples for Pfiesteria piscicida: A Dinoflagellate Associated with Fish Kills and Human Illness

Abstract

Pfiesteria piscicida, a heterotrophic estuarine dinoflagellate, has been associated with fish kills in North Carolina and Maryland [2, 3]. The rivers most affected in Maryland are tidal tributaries of the Chesapeake Bay, where many residents make their living on the water, either as commercial fishermen or in the recreation industry. During the summer of 1997, Maryland experienced a series of fish kills, mostly affecting Atlantic menhaden (Brevoortia tyrannus), with dramatic impact on the seafood and tourism industries of the State [5]. In addition, numerous persons that came into contact with water containing Pfiesteria piscicida developed skin rashes, flu-like symptoms, and cognitive problems [4, 7]. Due to the potential human health risks, extensive loss of fish, and economic impacts related to fish kills, the Maryland Department of Natural Resources (DNR) developed a comprehensive water quality monitoring program, initiated in 1998 and fully deployed in 1999 and 2000, to determine ecological parameters associated with Pfiesteria piscicida blooms. As part of this effort, water samples are collected monthly from stations throughout tributaries of the Chesapeake Bay and analyzed by our laboratory for the presence of the organism.