Mercury bioaccumulation in three colonial seabird species in the Gulf of Maine.

Autor: Laird LS; Dartmouth College, Department of Biological Sciences, LSC 6044, Hanover, NH 03755, USA. Electronic address: Lenny.S.Laird.23@dartmouth.edu., Craig EC; Shoals Marine Laboratory (Joint Program of University of New Hampshire and Cornell University), 8 College Rd., Durham, NH 03824, USA., Clucas G; Cornell Lab of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA., Taylor VF; Dartmouth College, Department of Earth Sciences, 6105 Fairchild, Hanover, NH 03755, USA., Chen CY; Dartmouth College, Department of Biological Sciences, LSC 6044, Hanover, NH 03755, USA.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2024 Oct 15; Vol. 947, pp. 174438. Date of Electronic Publication: 2024 Jul 01.
DOI: 10.1016/j.scitotenv.2024.174438
Abstrakt: The methylated form of mercury, MeHg, is a neurotoxin that bioaccumulates and biomagnifies through aquatic food webs, reaching high concentrations in top trophic species. Many seabird species are wide-ranging and feed on forage fish, so they can be used as sentinel species to assess the level of mercury in pelagic or coastal food webs because they integrate the signal from large areas and from lower trophic levels. The Gulf of Maine provides habitat for many seabirds, including endangered roseate terns (Sterna dougalii), common terns (Sterna hirundo), and the southernmost breeding population of black guillemots (Cepphus grylle). Hg levels were assessed in down of newly hatched chicks of three seabird species to determine pre-hatching Hg exposure. Stable isotopes (δ 15 N, δ 13 C) in down and chick contour feathers grown after hatching were used as indicators of adult female diet in the period before laying the egg (down) and pre-fledging chick diet (contour feathers). Black guillemot down THg concentrations were 10.07 ± 2.88 μg/g (mean ± 1SD), 5.5× higher than common tern down (1.82 ± 0.436 μg /g), and 7.4× higher than roseate tern down (1.37 ± 0.518 μg/g). Black guillemots also had higher down feather δ 15 N values (15.1 ± 0.52 ‰) compared to common (13.0 ± 0.72 ‰) or roseate terns (12.8 ± 0.25 ‰), and in black guillemot down feathers, higher Hg concentrations were correlated with δ 15 N, an indicator of trophic level. Repeated testing of the same tissue types across multiple years is needed to monitor THg exposure for seabirds in the Gulf of Maine; additionally, monitoring species composition and Hg presence in prey species of the black guillemot population would help to determine the source of high THg concentrations in this species.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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