Arctic methylmercury cycling

Jonsson, Sofi; Mastromonaco, Michelle Nerentorp; Wang, Fei‐Yue; Bravo, Andrea G.; Cairns, Warren R. L.; Chételat, John; Douglas, Thomas A.; Lescord, Gretchen L.; Ukonmaanaho, Liisa

doi:10.1016/j.scitotenv.2022.157445

Cited by 19 publications

(4 citation statements)

References 252 publications

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“…Permafrost peatlands have accumulated large Hg stores bound to organic matter (Lim et al., 2020; Schuster et al., 2018), and non‐permafrost peatlands are hotspots of MeHg production across the global boreal‐Arctic (Gordon et al., 2016; Poulin et al., 2019; Tarbier et al., 2021). However, few studies have examined concentrations and export of MeHg in northern rivers (Jonsson et al., 2022) and it remains unclear how strongly local hotspots of MeHg production influence the chemistry of catchment outlets.…”

Section: Introductionmentioning

confidence: 99%

Concentrations and Yields of Mercury, Methylmercury, and Dissolved Organic Carbon From Contrasting Catchments in the Discontinuous Permafrost Region, Western Canada

Thompson,

Low,

Shewan

et al. 2023

Water Resources Research

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Climate change and permafrost thaw may impact the mobilization of terrestrial dissolved organic carbon (DOC), mercury (Hg), and neurotoxic methylmercury (MeHg) into aquatic ecosystems; thus, understanding processes that control analyte export in northern catchments is needed. We monitored water chemistry for 3 years (2019–2021) at a peatland catchment (Scotty Creek) and a mixed catchment (Smith Creek) in the Dehcho (Northwest Territories), within the discontinuous permafrost zone of boreal western Canada. The peatland catchment had higher DOC and dissolved MeHg, but lower total Hg concentrations (mean ± standard deviation; 19 ± 2.6 mg DOC L−1; 0.08 ± 0.04 ng DMeHg L−1; 1.1 ± 0.3 ng THg L−1) than the mixed catchment (12 ± 4.4 mg DOC L−1; 0.05 ± 0.01 ng DMeHg L−1; 3.1 ± 2.2 ng THg L−1). Analyte concentrations increased with discharge at the mixed catchment, suggesting transport limitation and the flushing of near‐surface, organic‐rich flow paths during wet periods. In contrast, analyte concentrations in the peatland catchment were not primarily associated with discharge. MeHg concentrations, MeHg:THg, and MeHg:DOC increased with water temperature, suggesting enhanced Hg methylation during warmer periods. Mean open water season DOC and total MeHg yields were greater and more variable from the peatland than the mixed catchment (1.1–6.6 vs. 1.4–2.4 g DOC m−2; 5.2–36 vs. 6.1–10 ng MeHg m−2). Crucial storage thresholds controlling runoff generation likely drove greater inter‐annual variability in analyte yields from the peatland catchment. Our results suggest climate change may influence the production and transport of MeHg from boreal‐Arctic catchments as temperatures increase, peatlands thaw, and runoff generation is altered.

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Section: Introductionmentioning

confidence: 99%

Concentrations and Yields of Mercury, Methylmercury, and Dissolved Organic Carbon From Contrasting Catchments in the Discontinuous Permafrost Region, Western Canada

Thompson,

Low,

Shewan

et al. 2023

Water Resources Research

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“…For example, anthropogenic activities have increased exposure to chemical contaminants, such as mercury 16 , and global warming has potential to exacerbate this threat 17 – 19 . Mercury (Hg) is a prevalent contaminant that reaches even remote polar regions via a repeated process of condensation and evaporation, persists in cold environments, and biomagnifies up marine food chains 16 , 20 , 21 . The methylated form, methylmercury (MeHg) is especially bioavailable and harmful to wildlife 22 .…”

Section: Introductionmentioning

confidence: 99%

Keystone seabird may face thermoregulatory challenges in a warming Arctic

Grunst,

Grémillet

et al. 2023

Sci Rep

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Climate change affects the Arctic more than any other region, resulting in evolving weather, vanishing sea ice and altered biochemical cycling, which may increase biotic exposure to chemical pollution. We tested thermoregulatory impacts of these changes on the most abundant Arctic seabird, the little auk (Alle alle). This small diving species uses sea ice-habitats for foraging on zooplankton and resting. We equipped eight little auks with 3D accelerometers to monitor behavior, and ingested temperature recorders to measure body temperature (Tb). We also recorded weather conditions, and collected blood to assess mercury (Hg) contamination. There were nonlinear relationships between time engaged in different behaviors and Tb. Tb increased on sea ice, following declines while foraging in polar waters, but changed little when birds were resting on water. Tb also increased when birds were flying, and decreased at the colony after being elevated during flight. Weather conditions, but not Hg contamination, also affected Tb. However, given our small sample size, further research regarding thermoregulatory effects of Hg is warranted. Results suggest that little auk Tb varies with behavior and weather conditions, and that loss of sea ice due to global warming may cause thermoregulatory and energic challenges during foraging trips at sea.

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“…For instance, the neurotoxin and endocrine disruptor mercury (Hg) affects energetic traits, such as metabolic scope and BMR (Chastel et al, 2022; Gerson et al, 2019; Gilmour et al, 2019). Mercury from anthropogenic emissions reaches remote regions via long‐range transport and bioaccumulates up food chains (Jonsson et al, 2022). The methylated form is particularly hazardous for marine organisms (Chastel et al, 2022).…”

Section: Introductionmentioning

confidence: 99%

A keystone avian predator faces elevated energy expenditure in a warming Arctic

Grunst

Grémillet

et al. 2023

Ecology

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Climate change is transforming bioenergetic landscapes, challenging behavioral and physiological coping mechanisms. A critical question involves whether animals can adjust behavioral patterns and energy expenditure to stabilize fitness given reconfiguration of resource bases, or whether limits to plasticity ultimately compromise energy balance. In the Arctic, rapidly warming temperatures are transforming food webs, making Arctic organisms strong models for understanding biological implications of climate change‐related environmental variability. We examined plasticity in the daily energy expenditure (DEE) of an Arctic seabird, the little auk (Alle alle) in response to variability in climate change‐sensitive drivers of resource availability, sea surface temperature (SST) and sea ice coverage (SIC), and tested the hypothesis that energetic ceilings and exposure to mercury, an important neurotoxin and endocrine disrupter in marine ecosystems, may limit scope for plasticity. To estimate DEE, we used accelerometer data obtained across years from two colonies exposed to distinct environmental conditions (Ukaleqarteq [UK], East Greenland; Hornsund [HS], Svalbard). We proceeded to model future changes in SST to predict energetic impacts. At UK, high flight costs linked to low SIC and high SST drove DEE from below to above 4 × basal metabolic rate (BMR), a proposed energetic threshold for breeding birds. However, DEE remained below 7 × BMR, an alternative threshold, and did not plateau. Birds at HS experienced higher, relatively invariable SST, and operated above 4 × BMR. Mercury exposure was unrelated to DEE, and fitness remained stable. Thus, plasticity in DEE currently buffers fitness, providing resiliency against climate change. Nevertheless, modeling suggests that continued warming of SST may promote accelerating increases in DEE, which may become unsustainable.

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Arctic methylmercury cycling

Cited by 19 publications

References 252 publications

Concentrations and Yields of Mercury, Methylmercury, and Dissolved Organic Carbon From Contrasting Catchments in the Discontinuous Permafrost Region, Western Canada

Concentrations and Yields of Mercury, Methylmercury, and Dissolved Organic Carbon From Contrasting Catchments in the Discontinuous Permafrost Region, Western Canada

Keystone seabird may face thermoregulatory challenges in a warming Arctic

A keystone avian predator faces elevated energy expenditure in a warming Arctic

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