title: POPs in free-ranging pilot whales, sperm whales and fin whales from the Mediterranean Sea: Influence of biological and ecological factors.
abstract: The pilot whale Globicephala melas, the sperm whale Physeter macrocephalus, and the fin whale Balaenoptera physalus are large cetaceans permanently inhabiting the Mediterranean Sea. These species are subjected to numerous anthropogenic threats such as exposure to high levels of contaminants. Therefore, selected persistent organic pollutants POPs (29 PCBs, 15 organochlorine compounds, 9 PBDEs and 17 PCDD/Fs) were analysed in blubber biopsies of 49 long-finned pilot whales, 61 sperm whales and 70 fin whales sampled in the North Western Mediterranean Sea (NWMS) from 2006 to 2013. Contamination profile and species feeding ecology were then combined through the use of stable isotopes. δ(13)C, δ(15)N values and POPs levels were assessed through IR-MS and GC-MS respectively. To assess the toxic potency of the dioxin-like compounds, the TEQ approach was applied. δ(15)N values were 12.2±1.3‰ for sperm whales, 10.5±0.7‰ for pilot whales and 7.7±0.8‰ in fin whales, positioning sperm whales at higher trophic levels. δ(13)C of the two odontocetes was similar and amounted to -17.3±0.4‰ for sperm whales and -17.8±0.3‰ for pilot whales; whilst fin whales were more depleted (-18.7±0.4‰). This indicates a partial overlap in toothed-whales feeding habitats, while confirms the differences in feeding behaviour of the mysticete. Pilot whales presented higher concentrations than sperm whales for ΣPCBs (38,666±25,731 ng g(-1)lw and 22,849±15,566 ng g(-1) lw respectively), ΣPBDEs (712±412 ng g(-1) lw and 347±173 ng g(-1) lw respectively) and ΣDDTs (46,081±37,506 ng g(-1) lw and 37,647±38,518 ng g(-1) lw respectively). Fin whales presented the lowest values, in accordance with its trophic position (ΣPCBs: 5721±5180 ng g(-1) lw, ΣPBDEs: 177±208 ng g(-1) lw and ΣDDTs: 6643±5549 ng g(-1) lw). Each species was characterized by large inter-individual variations that are more related to sex than trophic level, with males presenting higher contaminant burden than females. The discriminant analysis (DA) confirmed how DDTs and highly chlorinated PCBs were influential in differentiating the three species. Pollutant concentrations of our species were significantly higher than both their Southern Hemisphere and North Atlantic counterparts, possibly due to the particular Mediterranean geomorphology, which influences pollutants distribution and recycle. Dioxin-like PCBs accounted for over 80% of the total TEQ. This study demonstrated (1) an important exposure to pollutants of Mediterranean cetaceans, often surpassing the estimated threshold toxicity value of 17,000 ng g(-1) lw for blubber in marine mammals; and (2) how the final pollutant burden in these animals is strongly influenced not only by the trophic position but also by numerous other factors such as sex, age, body size and geographical distribution.
authors.affiliation: Laboratory of Oceanology, MARE Centre, B6c, University of Liege, B6c, Allée du 6 Août, 4000 Liege, Belgium.
authors.forename: Marianna
authors.initials: M
authors.lastname: Pinzone
authors.affiliation: ISM/LPTC, Laboratory of Physical and Chemical Chemistry, University of Bordeaux I, 351 Cours de la Libération, 33405 Bordeaux, France; CNRS, EPOC, UMR 5805, F-33400 Talence, France.
authors.forename: Hélène
authors.initials: H
authors.lastname: Budzinski
authors.affiliation: WWF-France, 6 Rue des Fabres, 13001 Marseille France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Tasciotti
authors.affiliation: WWF-France, 6 Rue des Fabres, 13001 Marseille France.
authors.forename: Denis
authors.initials: D
authors.lastname: Ody
authors.affiliation: Laboratory of Oceanology, MARE Centre, B6c, University of Liege, B6c, Allée du 6 Août, 4000 Liege, Belgium.
authors.forename: Gilles
authors.initials: G
authors.lastname: Lepoint
authors.affiliation: Laboratory of Oceanology, MARE Centre, B6c, University of Liege, B6c, Allée du 6 Août, 4000 Liege, Belgium.
authors.forename: Joseph
authors.initials: J
authors.lastname: Schnitzler
authors.affiliation: CART, Laboratory of Mass Spectrometry LSM, University of Liege, B6C, Allée du 6 Août, 4000, Liege, Belgium.
authors.forename: George
authors.initials: G
authors.lastname: Scholl
authors.affiliation: CART, Laboratory of Animal Ecology and Ecotoxicology LEAE, University of Liege, B6c, Allée du 6 Août 11, 4000 Liege, Belgium.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Thomé
authors.affiliation: ISM/LPTC, Laboratory of Physical and Chemical Chemistry, University of Bordeaux I, 351 Cours de la Libération, 33405 Bordeaux, France; CNRS, EPOC, UMR 5805, F-33400 Talence, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Tapie
authors.affiliation: CART, Laboratory of Mass Spectrometry LSM, University of Liege, B6C, Allée du 6 Août, 4000, Liege, Belgium.
authors.forename: Gauthier
authors.initials: G
authors.lastname: Eppe
authors.affiliation: Laboratory of Oceanology, MARE Centre, B6c, University of Liege, B6c, Allée du 6 Août, 4000 Liege, Belgium. Electronic address: krishna.das@ulg.ac.be.
authors.forename: Krishna
authors.initials: K
authors.lastname: Das
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis; D004032:Diet; D004147:Dioxins / Q000032:analysis; D055669:Ecological and Environmental Phenomena; D004784:Environmental Monitoring; D005260:Female; D050617:Fin Whale; D020387:Food Chain; D055768:Halogenated Diphenyl Ethers / Q000032:analysis; D006843:Hydrocarbons, Chlorinated / Q000032:analysis; D008297:Male; D008522:Mediterranean Sea; D009587:Nitrogen Isotopes / Q000032:analysis; D012867:Skin / Q000737:chemistry; D050661:Sperm Whale; D014874:Water Pollutants, Chemical / Q000032:analysis*; D050686:Whales, Pilot
chemical_list: D002247:Carbon Isotopes; D004147:Dioxins; D055768:Halogenated Diphenyl Ethers; D006843:Hydrocarbons, Chlorinated; D009587:Nitrogen Isotopes; D014874:Water Pollutants, Chemical
keywords: Marine mammals; Mediterranean Sea; Persistent organic pollutants; Stable isotopes; Toxicity