Dams on Mercury Cycling: Case Study and Recommendations for

Overview

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Key numbers

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• M. Amyot1 F. Bilodeau2 A. Tremblay2 D. Planas3 D. Walsh4 D. E. Ponton1
• in the world and that this number may triple if all potential erally ranging from 10 to 50 MW, with 70% of countries
• large hydropower plants, due to the cumulative impact of with vast reservoirs (Bilodeau et al. 2017). In these
• standardization of Hg concentrations. The 95% confidence intervals
• regression (n = 30) to estimate (Hgstd) respected assumptions of nor- here) (Ponton et al. 2021). Specifically, northern pike and
• 23%), with values 2.9 times higher than in unflooded ones
• Total aqueous phosphorus (µg/L) dissolved CO2 and CH4 concentrations were super-saturated
• Fig. 4 Proportions of dissolved MeHg (%) as a function of dissolved in the channels and the pondages (Fig. 4), even 11 years
• shown: R2 = 0.48; p < 0.001; n = 43), and total aqueous phosphorous in these sectors. The constructed channels and bays of
• different river stretches (Fig. 3). Only sites with impound- observed relationship between phosphorus and %MeHg
• sector of Chute-Allard, where 51% of the variance in MeHg
• 4 content (%OM). Highest concentrations of Hg, MeHg and
• %OM were found in the pondage areas (Ferriz et al. 2021).
• 3 Concentrations of Hg and MeHg were best predicted by %
• Allard sites is shown: R2 = 0.54; p < 0.001; n = 19. For panel B, three
• p = 0.02; n = 10; for Chute-Allard sites (CA): R2 = 0.45; p = 0.002; transport of fresh organic matter from the watershed, in
• and partly attributed it to enhanced in situ MeHg production ROR (0.006 year), on the lower side of their ranges (HRT
• in the regulated stream. They also emphasized that elevated range: 0.002–2.36 years). They concluded that river dam-
• upstream or downstream. These results indicate that RORs %MeHg were all between 0 and 0.6%, ca. an order of
• food web and that many factors must be considered, such as Maurice (up to 10%) (Ferriz et al. 2021). We propose that
• power plants; 2.7 MW). This study mainly focused on fol- very low HRT (in the range of hours to days), significant
• zation (WHO; 0.5 ppm). In general, they found higher Hg become hotspots of MeHg production.
• 24% of soluble reactive phosphorus, this retention occurring carbon and Hg by runoff to the river during rain events
• leading to high Hg levels in top predators, sometimes compared to a mean of 30 years for large reservoirs (Bilo-
• follow-up period could be in the range of 20 years, con- Lawruk-Desjardins, Tania Charette, Jérémy de Bonville, Chanel
• focusing on reservoirs (Bilodeau et al. 2017; Lucotte et al. Natural Sciences and Engineering Research Council of Canada, by
• agencies, in order to address the issue of mercury with local Bilodeau F, Therrien J, Schetagne R (2017) Intensity and duration of
• Cossette CBP, Lacasse S, Bilodeau F, Côté Bhérer A (2019) Amén- Lavoie RA, Jardine TD, Chumchal MM, Kidd KA, Campbell LM
• Demarty M, Bilodeau F, Tremblay A (2021) Mercury Export From River Faced by Human Disturbances. Concordia University,
• Ferriz LM, Ponton DE, Storck V, Leclerc M, Bilodeau F, Walsh DA, Leclerc M, Ponton DE, Bilodeau F, Planas D, Amyot M (2023)
• Sacotte SCM, Bilodeau F, Eveno S (2020) Aménagements hydro- Sediments with Heavy Metals in Small Hydropower Cascade.

Methods (brief)

• M. Amyot1 F. Bilodeau2 A. Tremblay2 D. Planas3 D. Walsh4 D. E. Ponton1
• large hydropower plants, due to the cumulative impact of with vast reservoirs (Bilodeau et al. 2017). In these
• way as to increase the transfer of MeHg along the food web. (baseline levels) depending on fish species (Bilodeau et al.
• correlated with MeHg (Ponton et al. 2021). This implies a sediment samples, dominated by members of metabolically
• levels in fish from pondages than those collected down- In cases where the watershed is not disturbed (Fig. 6,
• focusing on reservoirs (Bilodeau et al. 2017; Lucotte et al. Natural Sciences and Engineering Research Council of Canada, by
• agencies, in order to address the issue of mercury with local Bilodeau F, Therrien J, Schetagne R (2017) Intensity and duration of
• Cossette CBP, Lacasse S, Bilodeau F, Côté Bhérer A (2019) Amén- Lavoie RA, Jardine TD, Chumchal MM, Kidd KA, Campbell LM
• Demarty M, Bilodeau F, Tremblay A (2021) Mercury Export From River Faced by Human Disturbances. Concordia University,
• Ferriz LM, Ponton DE, Storck V, Leclerc M, Bilodeau F, Walsh DA, Leclerc M, Ponton DE, Bilodeau F, Planas D, Amyot M (2023)
• flooding in free-flowing and regulated boreal rivers: an experi- Ponton DE, Lavoie RA, Leclerc M, Bilodeau F, Planas D, Amyot M
• Sacotte SCM, Bilodeau F, Eveno S (2020) Aménagements hydro- Sediments with Heavy Metals in Small Hydropower Cascade.

Implications

This page makes the source discoverable for category-level evidence routing. Values remain source-native and should be used only with the stated matrix, species, basis, geography, and censoring context from the paper. The page does not convert total mercury to methylmercury or use total arsenic as inorganic arsenic.

Wiki pages this source may touch

• Fish — marine, non-predatory (sardines, anchovies, salmon, cod)
• Mercury
• Mercury
• Arsenic

Verification notes

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Update history

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