Project title elucidating the health impacts of per and polyfluoroalkyl substances PFAS on an apex bird predator in the great lakes region river systems

This $620,000 Project Grant award from the U.S. Geological Survey's (USGS) Assistance to State Water Resources Research Institutes program (CFDA 15.805) will support research to elucidate the health impacts of per- and polyfluoroalkyl substances (PFAS) on bald eagles in the Great Lakes river systems. The University of Wisconsin-Madison, the awardee, will conduct monitoring and sampling activities over a 3-year period from January 2025 to January 2028. This includes collecting and analyzing blood from bald eagle nestlings, tissue samples from game fish, and water samples to understand PFAS contamination, dietary exposure, bioaccumulation, and impacts on the health and immune function of this apex predator species. The research aims to provide critical insights on PFAS contamination in an ecologically and culturally important species to inform long-term monitoring and protection efforts in the Great Lakes region.

Project period 1 7 2025 through 1 6 2028 purpose bald eagles haliaeetus leucocephalus are well known as the national bird, but also the story of the decimation of their populations due to widely used pesticides. Emerging per and polyfluoroalkyl substances PFAS can bioaccumulate in wildlife. Bald eagles are known as scavengers that will consume prey from both terrestrial and aquatic environments, which make them excellent indicators of contamination. Because of their varying diets, these species will likely result in different concentrations and compositions of PFAS that are unique to individual sites. This research will provide short term monitoring in the great lakes region and add to knowledge of PFAS sites to help steer more focused longterm monitoring initiatives, while providing information on PFAS contamination in a culturally important species. Legacy contaminants have shown detrimental impacts on reproduction in birds however, limited studies have examined the impacts of PFAS on the physiological responses of top predators and fewer exploring the impact on health and immune function. A healthy immune system is essential for wildlife biological stasis and protection against harmful parasites and may be a predictive of survival, reproduction, and overall fitness. Understanding the impacts of PFAS on animal health is necessary to protect and preserve species that depend on aquatic environments. Activities to be performed will sample blood from bald eagle nestlings 12WKS, tissue of game fish, and water in the wisconsin and ST. Croix river systems, in areas known to harbor a gradient of PFAS contamination due to historical production, use, and disposal. Stable isotope analysis will be completed to understand dietary niches, PFAS transportation in aquatic and terrestrial environments, and bioaccumulation rates. Eagle blood will be analyzed for a suite of PFAS. Using standard laboratory assays, the researchers will measure endocrine function, immune function, and identify pathogen infections to be able to associate contamination levels with hormone and immunological metrics. The researchers will conduct laboratory exposure assays to bridge the GAP between field and laboratory work. Expected outcomes the researchers expect to find high levels of PFAS in the river systems nearest historical production, use, and or disposal wisconsin river near rhinelande and varying levels of PFAS in different game fish throughout the river systems that will guide in creating new and revising old fish consumption guidelines for the state of wisconsin and minnesota. This shortterm monitoring assessment will steer a more focused monitoring plan that can be used for both understanding longterm trends in contamination and understanding future bioremediation efforts in these essential river systems. Results on health outcomes from eagles can be extrapolated to the potential impacts on humans and other wildlife species. Intended beneficiaries community members, including tribal nations, that utilize the ST. Croix and wisconsin river by providing accurate fish consumption guidelines. This work will help collect data for the widnr that can be used for setting fish consumption guidelines, determining sites of concern, developing longterm monitoring plans, and potential bioremediation sites. This work will provide information for future human PFAS studies. These results will be shared broadly to benefit as many community members as possible and have implications for economical and culturally important practices across the great lakes. Subrecipient activities the widnr will be participate in water, fish, and eagle sampling efforts across all sites. The field museum will participate in sampling and laboratory efforts.