Unique per- and polyfluoroalkyl substances (PFAS) source suggested by a Lake Trout (Salvelinus namaycush) PFAS...

Per- and polyfluoroalkyl substances (PFAS) are detected in pelagic freshwater fish and have deleterious effects on their health. It is unclear if traditional proxies for uptake of contaminants in fish (e.g., length, weight, age) predict fish PFAS concentrations. Here, we observe that summed PFAS concentrations are significantly higher in Lake Trout (Salvelinus namaycush) than other sportfish in Seneca Lake, New York. Carbon source (as proxied by δ¹³C) predicted variability within species, and trophic level (as proxied by δ¹⁵N) trended among species. A moderate inverse correlation (r = -0.51) was found between mercury and summed PFAS in Lake Trout. Summed PFAS concentrations and length, weight, or age were not statistically related, suggesting these characteristics are not reliable proxies for PFAS bioaccumulation. Length, weight, and age were significant predictors for mercury, indicating these drivers may be resulting in differential bioaccumulation in PFAS and mercury. In Seneca Lake, a unique PFAS composition was found for Lake Trout, where PFOS represents a lower proportion of summed PFAS than in other species in Seneca Lake, as well as relative to Lake Trout from other neighboring Finger Lakes. In addition, compared to Lake Erie and Lake Ontario, Lake Trout from Seneca Lake have higher concentrations of PFOA, PFNA, and PFDA, but lower proportions of PFOS. Lake Trout from Seneca Lake have a PFAS composition that consists almost exclusively of perfluoroalkyl carboxylic acids (PFCAs) and perfluorosulfonic acids (PFSAs), similar to the composition used in aqueous film forming foams (AFFF) before 2000 at a former military and current Superfund site in the lake's watershed.