Developing Non-lethal Biomarkers to Detect Exposure to Organic Contaminants in Aquatic Habitats

• Main Author: Meyers, Jennifer
• Format: Text
• Language: unknown
• Published: DigitalCommons@UMaine 2009
• Subjects: Biochemical markers; Design and construction; Water pollution; Environmental monitoring; Water quality; Aquaculture and Fisheries; Terrestrial and Aquatic Ecology; Water Resource Management; Atlantic salmon; Salmo salar
• Online Access: https://digitalcommons.library.umaine.edu/etd/1451; https://digitalcommons.library.umaine.edu/context/etd/article/2481/viewcontent/MeyersJ2009.pdf

Biomarkers have become essential tools to monitor organism responses to contaminant exposure and are continuously developed as new anthropogenic chemicals are released into the environment. Biomarkers can be used to determine if an organism has come into contact with and is responding to a contaminant and allows researchers to obtain information on the organism's ambient environment. The cytochrome P4501A (CYPIA) enzyme is a commonly used biomarker to determine if animals have been exposed to contaminants such as: polyaromatic hydrocarbons (PAHs), dioxin-like compounds, and polychlorinated biphenyls (PCBs, Melancon et al., 1992). As aquatic environments have become more infiltrated with contaminants due to run-off, effluents, and leaching, there has been greater emphasis on monitoring for CYPIA induction in fish and other aquatic organisms. Cytochrome P4501A induction is typically measured lethally through the ethoxyresorufin-o-deethylase (EROD) activity assay which measures the induction of CYP1A in the liver (Whyte et al., 2000); however, ERODs have also been measured using gills (Jonsson et al., 2002) and kidneys (Oriz-Delgado et al., 2008). Non-lethal methods are needed for endangered species when lethal sampling is prohibited, but would benefit all organisms that are exposed to contaminants. Gill filaments have been used in a lethal method to perform the EROD activity assay in various salmonids (Jonsson et al., 2002, 2003, and 2006); however, we were interested in using this assay in a non-lethal manner. We also had interest in using scales to measure EROD activity as it has been published that scales express CYP1A mRNA (Quiros et al., 2007). The experiments addressed in this thesis include utilizing Atlantic salmon (Salmo salar) parr and smolts to determine if a reliable, sensitive biomarker could be developed using gill filaments and scales in a non-lethal manner for the EROD activity assay. Atlantic salmon were chosen due to their endangered status and importance in Maine and their anadromous life ...