Development of a Non-lethal Biomarker of Contaminant Exposure for Threatened and Endangered Fish Species
PIs: Rebecca Van Beneden, University of Maine;
Adria Elskus, US Geological Survey, Maine Office; University of Maine
The National Need
The need for non-lethal assays in environmental science is growing rapidly. This is especially critical for endangered and threatened species in which the Endangered Species Act (ESA) requires permits to remove even a few individuals from the wild. Evaluating fish exposure to contaminants traditionally requires tissue extraction, typically a lethal procedure that cannot be used on listed species. Non-lethal approaches are urgently needed for evaluating chemical exposure and response to that exposure. One approach is to use non-lethal biochemical measurements to indicate both exposure and response.
Program Overview & Objectives
This proposal evaluates the potential of cytochrome P4501A (CYP1A) as a non-lethal biomarker of exposure and response to organic contaminants in an endangered fish species, Atlantic salmon ( Salmo salar ). CYP1A is a well-established biomarker that has been used for over 30 years as an indicator of contaminant exposure in fish, but its use with endangered species has been limited due to the lethal nature of the traditional assay. A non-lethal version of this assay would serve as an inexpensive screening tool to rapidly identify which fish species at which life stages are being exposed to organic contaminants, in what part of their geographic range they are likely being exposed, and, for migratory fishes, where along their migration route the exposure may be occurring. Such information would allow managers to identify 'hot spots' and species at risk and target these for more expensive chemical analyses.
Validation and use of this non-lethal bioassay would complement ongoing studies of Atlantic salmon migration and survival being conducted by NOAA-Fisheries, Maine Department of Environmental Protection's Bureau of Sea Run Fisheries and Habitat, University of Maine fisheries researchers, and the Maine USGS Cooperative Fish & Wildlife Research Unit. In addition, fish raised by the US Fish and Wildlife Service National Fish Hatcheries and by the Maine Department of Inland Fisheries and Wildlife state hatchery systems could be screened for evidence of exposure to organic contaminants, including PCBs, chlorinated pesticides, dioxins and furans, all of which have been detected in hatchery feeds, prior to release into Maine waters .
We will conduct laboratory experiments to compare a non-lethal (gill) to a lethal (liver) CYP1A assay in the juvenile life-stages of Atlantic salmon using a range of contaminant doses and exposure durations to evaluate the reliability and sensitivity of the non-lethal assay relative to the traditional lethal assay. If proven to be reliable and sensitive, the gill CYP1A assay will provide a rigorously tested, non-lethal screening tool for use in assessing contaminant exposure in threatened and endangered fish species.
US Geological Survey, Maine Field Office,
School of Biology & Ecology
5751 Murray Hall
University of Maine 04469-5751