Fin Whale as a Sink of Legacy and Emerging Contaminants: First Integrated Chemical Exposomics and Gene Expression Analysis in Cetaceans

Cetaceans face numerous
anthropogenic chemical stressors
in global
oceans, yet there is a lack of studies that simultaneously assess
their cumulative exposure to both legacy and emerging contaminants
and their combined effects. To evaluate the susceptibility of fin
whale (Balaenoptera physalus) to chemical
pollution, this study employed for the first time a multidiagnostic
molecular approach that integrates chemical exposomics and gene expression
analysis in live-sampled skin and blubber biopsies from two distinct
populations: the endangered Mediterranean subpopulation (Italy) and
the vulnerable population from the Sea of Cortez (Mexico). Both marine
regions are biodiversity hotspots characterized by different anthropogenic
impacts, making them ideal for the assessment of heterogeneous contaminants
exposure and their effects. Results revealed distinct exposure profiles
in the two populations, with Mediterranean fin whales exhibiting higher
concentrations of legacy pollutants such as polychlorinated biphenyls
(PCBs), as well as plasticizers, perfluoroalkyl substances (PFAS),
while both populations showed traces of pharmaceuticals and lifestyle-related
chemicals (e.g., paracetamol, diclofenac, nicotine, UV filters) and
other substances not previously reported in whales. Supported by 32
network correlations with gene expression relevant to transcriptional
regulation, endocrine disruption, lipid homeostasis, and inflammation,
our findings suggest that complex anthropogenic chemical exposures
may compromise the health and reproductive viability of the endangered
Mediterranean fin whales, affirming their importance as a global sentinel
species, which reflects marine ecosystem integrity within the “One
Health” framework.