Use of Biochemical Endpoints to Determine Relationships between Contaminants and Impaired Fish Health in a Freshwater Stream
Abstract:Bayou Bartholomew is a low gradient stream predominantly influenced by agricultural inputs and stormwater discharge from the urban areas of Pine Bluff, Arkansas. Preliminary studies indicated induction of hepatic cytochrome P450 1A protein (CYP1A) and CYP1A-catalyzed enzyme activity (ethoxyresorufin O-deethylase-EROD) in several fish species collected in the waterway, which meanders through residential areas of Pine Bluff, and forested regions in the outskirts of the city. Largemouth bass (Micropterus salmoides) showed CYP1A repression and a lack of correlation between CYP1A and EROD activity. In addition, hepatic heme oxygenase activity was elevated in several species and demonstrated an inverse relationship with hepatic CYP1A. Hepatic metallothionein was unchanged in any species collected from these locations. Four years after this evaluation, sediments were collected and analyzed for agents that could be mechanistically consistent with the biochemical responses observed. Utilizing seven criteria for causality, these data indicated that PCBs appear to be at least one group of agents responsible for the biological effects observed in fish species from the upper Bayou Bartholomew. While this supports causality under the criteria, further studies in this waterway would strengthen the relationship between this class of compound and the effects observed in resident fish species.
Document Type: Research Article
Affiliations: Environmental Toxicology Program, Department of Environmental Sciences, University of California, Riverside, Riverside, CA 92521; Tel(voice): 909-787-2018, Tel(fax): 909-787-3993; firstname.lastname@example.org
Publication date: 2003-01-01