Circumpolar assessment of mercury contamination: the Adélie penguin as a bioindicator of Antarctic marine ecosystems

Living in a Challenging Environment: Monitoring Stress Ecology by Non-Destructive Methods in an Antarctic Seabird

“…Therefore, measurements of Hg concentrations and isotopic values were made on a single randomly-selected feather for each bird. As described in Cusset et al (2023), feathers were first cleaned with a chloroform: methanol mixture (2:1), sonicated for 3 min, rinsed twice in methanol and dried at 45 • C for 48 h. They were then cut with stainless steel precision scissors to obtain a homogenous powder. Second, Hg analyses were performed in duplicate or triplicate (i.e., until the relative standard deviation between measurements reached <10 %) on feather homogenates (0.5-1.1 mg), using an Advanced Mercury Analyser (AMA 254, Altech).…”

“…Replicate measurements of reference materials (USGS-61 and USGS-63, US Geological Survey) indicated measurement uncertainties <0.10 ‰ for both δ 13 C and δ 15 N values. For further methodological information, please refer to Cusset et al (2023).…”

“…Bioaccumulation and biomagnification of methyl-Hg has received considerable attention in Arctic seabirds (e.g., Provencher et al, 2014;Braune et al, 2015;Albert et al, 2021;Chastel et al, 2022) as well as in Antarctic ones (e.g., Anderson et al, 2009;Carravieri et al, 2016;Becker et al, 2016). For Antarctic seabirds, latitudinal, age and sex differences in Hg contamination have been reported for several species such as wandering albatross (Diomedea exulans), emperor penguin (Aptenodytes forsteri) and Adélie penguin (e.g., Carravieri et al, 2014a;Pilcher et al, 2020;Cusset et al, 2023). The overall consequences on Antarctic seabird populations are that Hg can negatively affect population dynamics (Goutte et al, 2014a;Goutte et al, 2014b).…”