No Species Untouched: PFAS in Global Wildlife
PFAS contamination has been detected in wildlife species on every continent and in every ocean, from the high Arctic to the deepest oceanic trenches. The global distribution of PFAS in wildlife reflects the compounds’ extraordinary persistence, mobility through atmospheric and oceanic transport pathways, and tendency to bioaccumulate and biomagnify through food chains. For conservation biologists, toxicologists, and wildlife managers, PFAS has joined legacy contaminants like PCBs and DDT as a persistent organic pollutant reshaping wildlife health across ecosystems that appear, at first glance, pristine and remote.
Marine Mammals: Top Predators with the Highest Burdens
Marine mammals—cetaceans (dolphins, whales, porpoises) and pinnipeds (seals, sea lions, walruses)—occupy the top of marine food chains where PFAS biomagnification produces the highest tissue concentrations. Studies of bottlenose dolphins in the Charleston, South Carolina estuaries—a population that has been extensively monitored for chemical contaminant effects—detected PFAS levels associated with immune suppression in the range seen in heavily exposed human populations. Beluga whales in the St. Lawrence River estuary carry PFAS burdens reflecting both industrial contamination from the Great Lakes basin and marine dietary exposure pathways.
Arctic and Antarctic marine mammals—geographically remote from direct industrial PFAS sources—nonetheless carry significant PFAS body burdens due to long-range atmospheric and oceanic transport. Polar bear liver PFAS concentrations have increased over time in correlation with global PFAS production trends, serving as sentinels for global PFAS contamination trajectories. Ringed seals in the Canadian Arctic—the primary prey of polar bears and a subsistence food source for Inuit communities—carry PFAS that transfer both to their predators and to Indigenous human consumers, creating an environmental justice issue at the intersection of wildlife and human health.
Avian Species: PFAS in Raptors, Shorebirds, and Seabirds
Birds—particularly fish-eating raptors and seabirds that biomagnify aquatic contaminants—accumulate PFAS at concentrations associated with reproductive and developmental effects. Osprey, bald eagles, and great blue herons in PFAS-contaminated watersheds show liver and blood PFAS concentrations that experimental studies suggest may impair hatching success and chick survival. Studies of common loons in Maine and Minnesota have documented PFAS levels correlated with reduced chick production, though distinguishing PFAS effects from other environmental stressors requires careful statistical analysis.
Seabirds nesting in the North Sea—including common murres, razorbills, and puffins—carry PFAS reflecting the complex contaminant pool of their oceanic foraging environment. Laysan albatrosses nesting at Midway Atoll in the North Pacific carry PFAS transferred from their prey in the gyre environment, with concentrations that vary by colony and foraging range in ways that illuminate oceanic PFAS distribution patterns.
Freshwater and Terrestrial Wildlife
Freshwater fish in contaminated rivers and lakes worldwide carry PFAS at levels associated with fish consumption advisories in humans, suggesting biological significance for fish-eating wildlife as well. Mink—small carnivorous mammals with high metabolic rates and fish-dominated diets—have been used as sentinel species for PFAS exposure in aquatic environments, with Great Lakes mink populations showing PFAS-associated thyroid and reproductive effects. Terrestrial mammals in proximity to PFAS-contaminated military bases and industrial facilities accumulate PFAS through soil ingestion, contaminated water consumption, and prey consumption, creating wildlife populations serving as inadvertent indicators of environmental contamination extent.