title: Contrasted accumulation patterns of persistent organic pollutants and mercury in sympatric tropical dolphins from the south-western Indian Ocean.
abstract: Due to their high trophic position and long life span, small cetaceans are considered as suitable bioindicators to monitor the presence of contaminants in marine ecosystems. Here, we document the contamination with persistent organic pollutants (POPs) and total mercury (T-Hg) of spinner (Stenella longirostris, n =21) and Indo-Pacific bottlenose dolphins (Tursiops aduncus, n=32) sampled from the coastal waters of La Réunion (south-western Indian Ocean). In addition, seven co-occurring teleost fish species were sampled and analyzed as well. Blubber samples from living dolphins and muscle from teleosts were analyzed for polychlorinated biphenyls (PCBs), DDT and metabolites (DDTs), chlordanes (CHLs), hexachlorocyclohexanes (HCHs), hexachlorobenzene (HCB), and polybrominated diphenyl ethers (PBDEs). Methoxylated PBDEs (MeO-PBDEs), reported as having a natural origin, were also analyzed. T-Hg levels were measured in blubber and skin biopsies of the two dolphin species. Stable isotopes δ(13)C and δ(15)N values were determined in skin of the dolphins and in the muscle of teleosts. For PCBs, HCHs and T-Hg, concentrations were significantly higher in T. aduncus than in S. longirostris. For other POP levels, intra-species variability was high. MeO-PBDEs were the dominant compounds (55% of the total POPs) in S. longirostris, while PCBs dominated (50% contribution) in T. aduncus. Other contaminants showed similar profiles between the two species. Given the different patterns of POPs and T-Hg contamination and the δ(15)N values observed among analyzed teleosts, dietary and foraging habitat preferences most likely explain the contrasted contaminant profiles observed in the two dolphin species. Levels of each class of contaminants were significantly higher in males than females. Despite their spatial and temporal overlap in the waters of La Réunion, S. longirostris and T. aduncus are differently exposed to contaminant accumulation.
authors.affiliation: Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Department of Chemistry, "Al. I. Cuza" University of Iasi, 700506 Iasi, Romania.
authors.forename: Alin C
authors.initials: AC
authors.lastname: Dirtu
authors.affiliation: Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
authors.forename: Govindan
authors.initials: G
authors.lastname: Malarvannan
authors.affiliation: University of Liege, MARE Center, Laboratory for Oceanology, 4000 Liege, Belgium.
authors.forename: Krishna
authors.initials: K
authors.lastname: Das
authors.affiliation: Groupe Local d'Observation et d'Identification des Cétacés (GLOBICE), 30 Chemin Parc Cabris, Grand Bois, 97410 Saint Pierre, La Réunion, France.
authors.forename: Violaine
authors.initials: V
authors.lastname: Dulau-Drouot
authors.affiliation: Marine Sciences Program, Department of Biological Sciences, Florida International University, 3000 NE 151st, North Miami, FL 33181, USA.
authors.forename: Jeremy J
authors.initials: JJ
authors.lastname: Kiszka
authors.affiliation: University of Liege, MARE Center, Laboratory for Oceanology, 4000 Liege, Belgium.
authors.forename: Gilles
authors.initials: G
authors.lastname: Lepoint
authors.affiliation: Brigade Nature Océan Indien (BNOI)/ONCFS, 12 Allée de la Foret - Parc de la Providence, 97400 Saint Denis, La Réunion, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Mongin
authors.affiliation: Toxicological Centre, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium. Electronic address: adrian.covaci@uantwerpen.be.
authors.forename: Adrian
authors.initials: A
authors.lastname: Covaci
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry; D000818:Animals; D050681:Bottle-Nosed Dolphin / Q000502:physiology*; D017753:Ecosystem; D004781:Environmental Exposure; D004784:Environmental Monitoring; D005247:Feeding Behavior; D055768:Halogenated Diphenyl Ethers / Q000378:metabolism; D006843:Hydrocarbons, Chlorinated / Q000378:metabolism; D019156:Indian Ocean; D008628:Mercury / Q000378:metabolism; D011078:Polychlorinated Biphenyls / Q000378:metabolism; D017508:Reunion; D012867:Skin / Q000737:chemistry; D013045:Species Specificity; D050706:Stenella / Q000502:physiology*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D055768:Halogenated Diphenyl Ethers; D006843:Hydrocarbons, Chlorinated; D014874:Water Pollutants, Chemical; D011078:Polychlorinated Biphenyls; D008628:Mercury
keywords: Hg; La Réunion; POPs; Stenella longirostris; Tursiops aduncus; stable isotopes