Chemical stressors of many classes impact on fisheries in the Great Lakes to different degrees and on many levels, and are a priority with the U. S. Fish and Wildlife Service, the U. S. Environmental Protection Agency, and Great Lakes basin states, Canadian provinces, and their municipalities. The combination of the large surface area and volume; heavy concentration of agriculture, industry and municipal development; and the long hydraulic retention time of the Great Lakes make fisheries particularly susceptible to these stressors. For the past three decades, through cooperative agreements with numerous basin agencies and research programs, the Center program has provided sound science and needed information to the Great Lakes basin community through monitoring contaminant behavior, fate, and transport studies, as well as hazard assessment. Recent studies traced the emergence and behavior of polybrominated diphenyl ethers, an emerging contaminant class of fire retardant chemicals. Also, recent studies of archived rainbow smelt tissue (1983-2002) helped determine species sensitivity to contaminated sediment in the basin, and provided critical Great Lakes food web data. We have developed a nonlethal tissue sampling method to provide necessary residue data to assist in lake sturgeon recruitment studies. The tissue data provided by this study supplement a meager lake sturgeon contaminant body burden database existing in the Great Lakes basin. The Center program has shifted emphasis recently from residue monitoring to food and energy web considerations, including the elucidation of chemical stressor trophic transfer patterns, bioaccumulation, and like problems important to the Center mission.

The present research efforts under this task have three interrelated concentrations: chemical stressor identification and pathway elucidation of trophic transfer interference, chemical property estimation, and risk/hazard assessment. There is need to elucidate the identity and trophic transfer pathways of many of these chemical stressors, which include both traditional and emerging issue contaminants as well as dietary components. Cause-and-effect linkages have been made for many chemical stressors with lethal and sub-lethal problems involving trophic transfer interferences through food and energy webs for fish and wildlife. The acquisition of both skills and ability to use the stable isotope technique to help investigate trophic transfer interferences has become a high priority.

Once identified, the hazard these stressors present to Great Lakes biota are assessed and communicated. However, data needed to reliably perform accurate hazard and risk assessments on the thousands of compounds in use and introduced yearly are available for only a small fraction these compounds. As time, equipment, and funding considerations make the requisite data collection impossible, there is urgent need to obtain reliable estimates of physical properties, potential hazard, and ultimate environmental fate. Quantitative structure-activity relationship (QSAR) investigations create models that correlate numerous types of chemical descriptors with published environmental activity and fate to provide, very quickly and very inexpensively, reliable data for hazard screening and other purposes. Periodic physical property determinations have been made for compounds (classes) for national contaminant oversight groups such as Interagency Testing Committee (ITC), and investigations of "hot topics", such as endocrine disruption, natural bioremediation, and emerging contaminant issues. Center QSAR investigations have resulted in prototype expert system software (PredTox 2003) designed for estimation of physicochemical properties for stressors including toxic endpoints for organisms. This software, very useable by field personnel, allows for rapid toxicity and other property estimation for a very wide variety of environmental organic, organometallic, and inorganic/heavy metal contaminants. Estimation of even rudimentary metal environmental behavior has proven very difficult to date in QSAR investigations, and our investigations have put the Center on the cutting edge in this field. To access the PredTox software, please refer to PredTox: Theory of Operation

The third phase involves determination of risk associated with the contaminants found in the environment. The projects range from the cellular to population impacts. Fish, wildlife, and other aquatic biota of the Great Lakes watershed have been diminished by degraded habitats that have been chemically or physically altered by anthropogenic activity. We have been instrumental in establishing guidelines and a protocol for aquatic risk assessment during work with the USEPA on Great Lakes Areas of Concern (AOC).

The long-term goal of this Center program is to provide improved capability to assess the hazard and impact of thousands of observed and potential chemical stressors found in fish, sediment, and water on trophic transfer processes of the Great Lakes food and energy webs. In order to achieve the long-term goal, we 1) make analytical measurements of chemical stressors for identification and quantitation (where necessary), and elucidate stressor impacts on trophic transfer through food and energy webs, 2) either use existing or develop new (where needed) mathematical models and chemical property databases to help compile necessary physicochemical information to describe chemical stressor environmental behavior including toxicity, persistence and bioaccumulation potential, 3) develop a hazard ranking using additional literature data on toxicities, bioaccumulation, biodegradation, and sources, 4) assess risk of site-specific contamination to biota, and when possible 5) suggest remediation strategies.

Contaminant Biology Fact Sheet
New! PREDTOX 2003 Theory of Operation