RESUMO
Liver concentrations of eight polybrominated diphenyl ethers (ΣPBDEs: sum of brominated diphenyl ethers [BDE]-28, -47, -99, -100, -153, -154, -183, and -209) ranged from 135 to 985 ngg(-1) lipid weight (lw) in coastal herring gulls (Larus argentatus) from the marine Hvaler Archipelago (The Glomma River Estuary), Norway. Hexabromocyclododecane (HBCD) concentrations ranged from 10 to 698 ngg(-1)lw. High range in δ(13)C indicates that gulls were subject to a diversity of carbon sources, likely reflecting their mixed feeding on terrestrial and marine organisms, or diversity of autochthonous and allochthonous (watershed) energy sources at the bases of their marine/estuarial food chains. Inverse relationships of HBCD, and to somewhat lesser extent of BDE-209, with δ(13)C values suggest higher abundance of these compounds in the land-derived energy-sources of the gulls. Inverse relationships of BDE-99, BDE-183 and BDE-209 with δ(15)N suggest that trophic relationships affect bioaccumulation of these compounds in the herring gulls, with greater bioaccumulation from lower trophic level prey species. This may be because these PBDE congeners are subject of debromination in higher trophic levels prey species of the gulls (e.g., teleost fish). Levels of BDE-209 (up to 95 ng/g lipid) of these herring gulls from 1998 were in the higher range reported in European birds, and not matched by other reports in North Sea seabirds. The present study suggests that the currently used brominated flame-retardants (BFRs), BDE-209 and HBCD relate to changing nutrient allocation in the herring gulls, and represent a risk to seabirds exploiting near-shore and estuary ecosystems.
Assuntos
Charadriiformes , Retardadores de Chama/farmacocinética , Cadeia Alimentar , Éteres Difenil Halogenados/farmacocinética , Animais , Isótopos de Carbono/análise , Feminino , Peixes , Hidrocarbonetos Bromados/farmacocinética , Masculino , Isótopos de Nitrogênio/análise , Mar do Norte , NoruegaRESUMO
Phocid seals have lipid rich milk, which is known to serve as a transfer medium through which persistent organic pollutants (POPs) move from mother to offspring during lactation. However, knowledge on this generational transfer of different POPs and the partitioning of these compounds in maternal and offspring tissues over the course of the lactation are limited. In this study we examined the qualitative and quantitative partitioning of a range of chlorinated POPs in maternal blubber, blood and milk as well as in pup blubber, collected early in the lactation period and late in the lactation period. In the lactating female, the high-chlorinated and hydrophobic compounds were passed less efficiently into the milk than the low-chlorinated compounds and more water-soluble compounds. Significantly, lower maternal blood concentrations than in maternal blubber biopsies suggest a stratification of POP concentrations in the blubber column of lactating female and lower concentrations in the metabolic active inner layers. Over the course of lactation, there was a significant increase in maternal blood and milk concentrations of POPs as opposed to no change in maternal blubber biopsy concentrations. This was most apparent for the hydrophobic and high-chlorinated compounds. The most likely explanation for this is that the metabolic active inner blubber layer, from which the milk lipids are derived from, is in steady state with the circulatory system, while the outer layers are more static and only slowly respond to changes in concentrations elsewhere in the body. The concentrations of the high-chlorinated and hydrophobic compounds were substantially lower in pup blubber than in maternal blubber. This probably relates the combined effect of these compounds stratification in maternal blubber and their slow transfer into the milk. The present study shows that the more hydrophobic and high-chlorinated compounds come to steady state less quickly in the different tissues than the more water-soluble and low-chlorinated compounds in the lactating female and her offspring. This has implications for which matrices to choose when sampling for assessing the toxicological risk of POPs in seals.