Whale Baleen To Monitor Per- and Polyfluoroalkyl Substances (PFAS) in Marine Environments

Per- and polyfluoroalkyl substances (PFAS) comprise >10 000 synthetic compounds that are globally distributed and highly persistent but remain challenging to monitor. Here we assess the utility of baleen─an accreting, keratinaceous tissue that baleen whales use for filter-feeding─to track PFAS dynamics in marine food webs. In six species investigated, PFAS were detected in all baleen tested (n = 18 plates, 220 samples, ∑₁₀PFAS range of 0.02–60.5 ng/g of dry weight), at levels higher than those of other tissue types besides liver. Three of the species in our data set had not been tested for PFAS contamination previously, and two of those species (blue whale and North Atlantic right whale) are internationally endangered species. Apparent links were observed between PFAS and life-history events by testing successive subsamples along the growth axis of the baleen plates. These results establish baleen as a viable sample matrix for assessing PFAS contamination in marine ecosystems by enabling multiyear time-series analyses through single-tissue sampling with seasonal resolution.