Trace analysis of lipid-rich tissue and bile will focus on mercury, PAHs, PCBs and toxaphene, persistent chemicals that are elevated along the GA coast. Preliminary evaluation of an assay that measures DNA damage in various tissue types suggests its utility as an aquatic biomonitoring tool. About 40 out of the 110 possible references were selected, reviewed, and categorized by the species monitored, the chemicals of interest, and their utility in the lab or the field. Candidate biomarker classes and endpoints recommended for Georgia coastal aquatic species. Chemical residue analysis has been used in a number of large-scale biomonitoring programs as an indicator of contaminant bioavailability.
Fish are capable of transforming PAHs into polar metabolites which are then readily excreted.
The interaction of chemicals with cellular DNA can result in strand modifications, breaks, and cross-linkages, and thus is a biomarker of contaminant exposure. Several methods such as alkaline elution, unwinding and precipitation have been used to measure the amount of DNA strand breaks in various tissues. Cytochrome P450 are enzymes that are induced when an organism is exposed to certain classes of xenobiotic compounds. Contaminants, through redox recycling, have the ability to produce ROS in excess of the level of protection offered by antioxidant defense mechanisms, thus leading to DNA damage. Chemicals including many organochlorines have been shown to alter the hormonal balance in developing and mature fish.