Chesapeake Ecotox Research Program: Research

Surrogate Species

Amphipod, Leptocheirus plumulosus. Benthic amphipods are increasingly favored for evaluating sediment toxicity because they are sensitive to a wide range of contaminants (Swartz et al. 1979; MDE 1991; USEPA/USACE 1991, 1994; US EPA 1996). Leptocheirus plumulosus, an ecologically-important estuarine species in Chesapeake Bay (Diaz and Schaffner 1990), is easily cultured, exhibits high survival under a variety of environmental test conditions and displays sensitivity to reference toxicants similar to those of other amphipods (Schlekat et al. 1992; Kane Driscoll et al. 1997). Standardized methods that use Leptocheirus to evaluate chronic effects of contaminated sediments (McGee et al. 1993; USACE 1996; De Witt 1997, personal communication) have been used in Chesapeake Bay (McGee et al. 1999). These factors contribute to the value of using Leptocheirus to assess current sediment quality, and to imply levels of clean-up required to minimize impacts from sediment-associated pollutants.

Leptocheirus plumulosus

Finfish, Fundulus spp. The genus Fundulus includes several species of widely studied, ecologically- important, nonmigratory estuarine fish (Bigelow and Schroeder 1953; Fritz et al. 1975), with F. heteroclitus common in saline parts and F. diaphanus common in tidal freshwater regions of Chesapeake Bay. Increasingly popular sentinels of environmental contamination in biomarker and population genetics studies, these fish exhibit a dose-dependant response to contaminants (e.g., PAHs, PCBs, Van Veld et al. 1997) and elevated prevalence of hepatic and extrahepatic lesions with increasing pollution (Vogelbein et al. 1990). Reproduction, embryonic development, and behavioral characteristics are well studied, as are teratogenic effects of environmental toxicants (Atz 1986; Weis 1989; Zhou and Weis 1998). These small fish are easily collected, inexpensive to maintain and rear, breed several times a year and bear large, easily visualized eggs and embryos. An EPA STAR-funded study of Fundulus population genetics in the Elizabeth River currently underway will provide insights into use of this species.

[Mummichog]