Carryover effects of winter mercury contamination on summer concentrations and reproductive performance in little auks
International audience Many animals migrate after reproduction to respond to seasonal environmental changes. Environmental con-ditions experienced on non-breeding sites can have carryover effects on fitness. Exposure to harmful chemicalscan vary widely between breeding and non-breeding grounds, but...
Published in: | Environmental Pollution |
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Main Authors: | , , , , , , , , , , , , , , , , |
Other Authors: | , , , , , , , , , , , , , , , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2023
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Subjects: | |
Online Access: | https://hal.univ-brest.fr/hal-04029591 https://doi.org/10.1016/j.envpol.2022.120774 |
Summary: | International audience Many animals migrate after reproduction to respond to seasonal environmental changes. Environmental con-ditions experienced on non-breeding sites can have carryover effects on fitness. Exposure to harmful chemicalscan vary widely between breeding and non-breeding grounds, but its carryover effects are poorly studied.Mercury (Hg) contamination is a major concern in the Arctic. Here, we quantified winter Hg contamination andits carryover effects in the most abundant Arctic seabird, the little auk Alle alle. Winter Hg contamination of birdsfrom an East Greenland population was inferred from head feather concentrations. Birds tracked with GlobalLocation Sensors (GLS, N = 28 of the total 92) spent the winter in western and central North Atlantic waters andhad increasing head feather Hg concentrations with increasing longitude (i.e., eastward). This spatial pattern wasnot predicted by environmental variables such as bathymetry, sea-surface temperature or productivity, and needsfurther investigation. Hg concentrations in head feathers and blood were strongly correlated, suggesting acarryover effect of adult winter contamination on the consequent summer concentrations. Head feather Hgconcentrations had no clear association with telomere length, a robust fitness indicator. In contrast, carryovernegative effects were detected on chick health, as parental Hg contamination in winter was associated withdecreasing growth rate of chicks in summer. Head feather Hg concentrations of females were not associated withegg membrane Hg concentrations, or with egg volume. In addition, parental winter Hg contamination was notrelated to Hg burdens in chicks’ body feathers. Therefore, we hypothesise that the association between parentalwinter Hg exposure and the growth of their chick results from an Hg-related decrease in parental care, and needsfurther empirical evidence. Our results stress the need of considering parental contamination on non-breedingsites to understand Hg trans-generational effects in migrating ... |
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