Re-evaluation of the Relationship between Pfiesteria and Estuarine Fish Kills

Abstract

In recent years, fish kills along the mid-Atlantic US coast have become an increasing problem, with important economic, environmental, and public health implications (Glasgow and others 1995; Burkholder 1998; Grattan and others 1998; Haselow and others 2001; Shoemaker and Hudnell 2001). Research into the causes of these fish kills is ongoing, and monitoring and surveillance programs have been instituted to investigate (among other factors) the role of actively toxic forms of two known species within the dinoflagellate genus Pfiesteria (Burkholder and others 1995, 2001a; Steidinger and others 1996; Burkholder and Glasgow 1997; Glasgow and others 2001b). In their recent analyses of the relationship between Pfiesteria and fish kills, Burkholder and others (1999) and Stow (1999) stated, as others have noted previously (Meyer and Barclay 1990), that it is difficult to establish the causes of estuarine fish kills at the ecosystem level. The evaluation of Burkholder and others (1999) was based on the biology and toxic behavior of Pfiesteria, as well as empirical sampling of field fish kill events then in progress, as supported by laboratory analyses of samples collected from each fish kill. In contrast, Stow (1999) conducted theoretical probability calculations and argued that information demonstrating the presence of toxic Pfiesteria during fish kills was insufficient to prove that there was a cause-and-effect