Ecotoxicological Characterization of Type C Killer Whales From Terra Nova Bay (Ross Sea, Antarctica): Molecular Biomarkers, Legacy, and Emerging Persistent Organic Contaminants

Among killer whale forms, type C is a fish-eating form and the most common in Ross Sea. In austral summer 2015, study was conducted to evaluate toxicological hazard these marine mammals face Antarctic ecosystem. Seven biopsy samples were collected from adult individuals (five males two females) surroundings of Italian Research Station Mario Zucchelli, Terra Nova Bay, by remote dart sampling pack ice. The accumulation levels persistent organic pollutants (POPs) such as legacy (DDTs, PCBs, HCB) emerging (PBDEs DP) measured. Moreover, protein expression cytochrome P450 (CYP1A1 2B) mRNA level variations peroxisome proliferator-activated receptors ? ? ( PPAR - ?) estrogen receptor ER ?), aryl hydrocarbon AhR ), Cyp1a evaluated. Twenty PCB congeners, six DDTs, HCB, three HCHs, fourteen brominated BDEs DP-syn anti-isomers analyzed on freeze-dried blubber GC-MS. evaluated Western Blot quantified quantitative real-time PCR. average abundance pattern for contaminants DDTs > PCBs HCB HCHs ? PBDEs >> DP. Contaminant resulted be lower when compared existing data whales McMurdo Sound (Ross Sea) those reported worldwide. five target genes successfully quantified, but no statistical correlation found with POP levels, suggesting that either low POPs may not significantly affect biological responses investigated, or other stressors could contribute alterations molecular biomarkers. Although results showed risk related contamination more impacted areas, this provides baseline conservation species an area high ecological value, recently declared largest Marine Protected Area Antarctica, where should remain at minimum despite increasing multiple stresses region.