title: Influence of trophic ecology on the accumulation of dioxins and furans (PCDD/Fs), non-ortho polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) in Mediterranean gulls (Larus michahellis and L. audouinii): A three-isotope approach.
abstract: The impact of pollution caused by severe anthropogenic pressure in the Mediterranean Sea, an important biodiversity hotspot, requires continuous research efforts. Sources of highly toxic chemicals such as Persistent Organic Pollutants (POPs) are misunderstood in representative Mediterranean species, which limits our capability to establish proper conservation strategies. In the present study, eggs of Audouin's and yellow-legged gulls (Larus audouinii and L. michahellis) were used to investigate the trophic sources, as measured by δ(13)C, δ(15)N, and δ(34)S, of legacy POPs, in particular, polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and non-ortho polychlorinated biphenyls (no-PCBs), as well as recently-regulated POPs, e.g., polybrominated diphenyl ethers (PBDEs). Special attention was paid to the usefulness of rarely-explored δ(34)S ratios in explaining POP exposure in wildlife, and δ(34)S was the isotopic ratio that best explained POP variations among gulls in most cases, thus demonstrating its usefulness for understanding POP exposure in wildlife. Significant relationships between stable isotope signatures and POP concentrations revealed increasing levels of no-PCBs and low halogenated PCDD/Fs and PBDEs in Mediterranean gulls as the consumption of marine resources increases. In contrast, highly chlorinated and brominated congeners appeared to preferentially accumulate in gulls feeding primarily on refuse from dump sites and terrestrial food webs. The use of suitable dietary tracers in the study of POPs in yellow-legged gulls revealed the importance of dump sites as a source of POPs in Mediterranean seabirds, which has not previously been reported. In contrast, the preferential accumulation through marine food webs of low chlorinated PCCD/Fs and no-PCBs, which show the highest toxic equivalents factors (TEFs), led to a significantly greater toxicological concern in Audouin's as compared to yellow-legged gulls. Audouin's gull exposure to POPs appears primarily related to the pelagic food webs commonly exploited by fisheries, highlighting the need for further research given the potential impact on human consumption.
authors: Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, IQOG-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain. Electronic address: jlroscales@iqog.csic.es.
authors: Jose L
authors: JL
authors: Roscales
authors: Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, IQOG-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain.
authors: Alba
authors: A
authors: Vicente
authors: Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, IQOG-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain.
authors: Juan
authors: J
authors: Muñoz-Arnanz
authors: Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
authors: Laura
authors: L
authors: Morales
authors: Department of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
authors: Esteban
authors: E
authors: Abad
authors: Department of Zoology and Physic Anthropology, Faculty of Biology, University Complutense of Madrid, José Antonio Novais 2, Ciudad Universitaria, 28040 Madrid, Spain.
authors: Jose I
authors: JI
authors: Aguirre
authors: Department of Instrumental Analysis and Environmental Chemistry, Institute of Organic Chemistry, IQOG-CSIC, Juan de la Cierva 3, 28006 Madrid, Spain.
authors: Begoña
authors: B
authors: Jiménez
mesh_terms: D000818:Animals; D046091:Charadriiformes / Q000378:metabolism*; D000072338:Dibenzofurans, Polychlorinated / Q000032:analysis* / Q000378:metabolism; D004463:Ecology; D004531:Eggs / Q000032:analysis; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000032:analysis* / Q000378:metabolism; D005398:Fisheries; D020387:Food Chain; D055768:Halogenated Diphenyl Ethers / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D007554:Isotopes; D008522:Mediterranean Sea; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000378:metabolism; D000072317:Polychlorinated Dibenzodioxins / Q000032:analysis* / Q000378:metabolism
chemical_list: D000072338:Dibenzofurans, Polychlorinated; D004785:Environmental Pollutants; D055768:Halogenated Diphenyl Ethers; D007554:Isotopes; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls
keywords: POPs; Seabirds; Stable isotopes; Trophodynamics; δ(34)S