Persistent organic pollutants in sea bird eggs from the Indian Oceans Mascarene Basin

• We report the concentrations of persistent organic pollutants (POPs) in seabird eggs from St. Brandons Atoll, a tropical island system in the western Indian Ocean. Ten eggs each of sooty terns (Onychoprion juscatus), fairy terns (Gygis alba), and common noddies (Anous stolidus) were collected from the atoll. For a terrestrial reference, we analysed three feral chicken (Gallus gallus domesticus) eggs from the same location. Sooty tern eggs contained the highest mean concentrations of three chemical classes: Sigma CHL3 (0.21 ng/g wm; wet mass), Sigma PCB10 (1.5 ng/g wm), and Sigma PBDE6 (1.1 ng/g wm). Fairy tern eggs contained the highest mean concentrations of HCB (0.68 ng/g wm) and Sigma CHB5 (0.83 ng/g wm). The chicken eggs contained the highest mean concentrations of Sigma DDT3 (2.6 ng/g wm), while common noddy eggs contained the highest mean concentrations of Sigma HCH2 (0.5 ng/g wm). We surmise that the differences in chemical composition between species reflect different pollutant compositions in prey from the birds different foraging ranges. The sooty terns foraging offshore contained higher POPs concentrations than the nearshore-foraging common noddies. Fairy tern eggs contained intermediate concentrations, commensurate with their intermediate foraging. Inter-island differences in contaminant concentrations were seen between eggs of the common noddies from St. Brandons Atoll and Rodrigues Island, 520 km to the south-east. Concentrations of contaminants found in this study were lower than values quantified by other studies, making St. Brandons Atoll an ideal reference site to monitor background concentrations of POPs in the tropical Indian Ocean. (C) 2021 Elsevier B.V. All rights reserved.

Ämnesord

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Miljövetenskap (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Environmental Sciences (hsv//eng)

Nyckelord

Biomonitoring; DDT; Mauritius; PBDE; PCB; Seabird eggs

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