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Elevated invertebrate methylmercury concentrations across functional feeding groups in a eutrophic bog post-flooding
M Doncaster1, N K Hillier1, N J O'Driscoll1
1Acadia University, Wolfville, Nova Scotia, B4P 2R6, Canada.
The Science of the Total Environment
|June 19, 2026
Summary
Methylmercury (MeHg) concentrations in Big Meadow Bog invertebrates were 1.61 times higher than at undisturbed sites. This highlights the role of disturbed wetlands as potential hotspots for mercury contamination, posing risks to food webs.
Area of Science:
- Environmental Science
- Ecotoxicology
- Wetland Ecology
Background:
- Mercury is a persistent environmental contaminant transported long distances, accumulating in ecosystems.
- Methylmercury (MeHg) biomagnification in food webs poses risks to top predators.
- Low trophic level invertebrates serve as crucial indicators of ecosystem health and contamination.
Purpose of the Study:
- To investigate the impact of nutrient enrichment (guano) and water table restoration on mercury speciation and accumulation in Big Meadow Bog.
- To assess methylmercury (MeHg) and total mercury (THg) concentrations in aquatic and terrestrial invertebrates and surface waters.
- To determine bioconcentration factors (BCFs) for MeHg in different invertebrate families and functional feeding groups (FFGs).
Main Methods:
- Sampling of aquatic and terrestrial invertebrates and surface waters from Big Meadow Bog.
- Analysis of methylmercury (MeHg) and total mercury (THg) concentrations in all samples.
- Calculation of bioconcentration factors (BCFs) for MeHg in relation to water concentrations.
Main Results:
- Significant differences in MeHg concentrations were observed across invertebrate families and functional feeding groups (FFGs).
- Average MeHg concentrations in Big Meadow Bog were 1.61 times higher than those found at similar undisturbed sites.
- Bioconcentration factors (BCFs) varied among invertebrate taxa, indicating differential mercury uptake and accumulation.
Conclusions:
- Disturbed wetland habitats, like Big Meadow Bog, can act as significant sources or sinks for methylmercury.
- Invertebrate community structure and feeding ecology influence mercury bioaccumulation.
- The elevated MeHg levels underscore the importance of monitoring contaminated sites to protect ecosystem health and food web integrity.
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