Is resistance common in other resident species in the HR? Brown bullhead, pumpkinseed Lep-omis gibbosus, and largemouth bass Micropterus salmoides collected near Poughkeepsie, New York, and matched reference fish from a hatchery were treated with PCB77 and EROD activity was measured. EROD was induced in all three species of hatchery origin and in pumpkinseed and bullhead, but not in bass from the HR, indicating that resistance had developed in only one of three co-occurring species (Zielinski, 2001) (Fig. 30.5). Additional studies of largemouth bass demonstrated that although CYP1A was not induced by PCB77, it was by B[a]P. Although exposure to B[a]P increased EROD similarly in bass from the HR and hatchery, HR bass formed 60 percent fewer B[a]P-DNA adducts than the hatchery bass (Zielinski, 2001). Nacci et al. (2002) also reported reduced levels of B[a]P-DNA adducts in resistant killifish from New Bedford Harbor, however these fish also were less responsive to induction of EROD activity by B[a]P.
Was this article helpful?