Seasonality in Hg concentration in Arctic seabirds

Even far from intensive anthropogenic activities, concentrations of mercury (Hg), neurotoxic affecting human and animal health, are measured in the Arctic. The highest concentrations are measured in top predators such as seabirds, found at the end of the food chains. Most of the knowledge regarding Hg contamination of Arctic seabirds is about the breeding period, when seabirds aggregate in large colonies, in land, where they are more easily accessible. However, the non-breeding period, being a critical part of the year (e.g. light conditions, prey availability, storms), have to be studied to fully understand the risks associated with pollutant and seabirds survival. In the present study, we used nine species of Arctic seabirds at the pan-Arctic scale and specific feathers informing about Hg contamination during both breeding and non-breeding periods. Our results show that most seabirds are exposed to higher contamination during the non-breeding period. We also found spatial variations with different concentrations between the Pacific and Atlantic Arctic. In addition, seabirds breeding in the West Atlantic seem to be exposed to higher toxicity risks than population breeding anywhere else in the Arctic.
Here is the infographic summarising those results. The paper can be find here: https://hal.archives-ouvertes.fr/hal-02949049/document