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Mercury

Sediment

Mercury (mg/kg dry weight)

Mussels

Mercury (mg/kg wet weight)
North
0.0201 mg/kg
0.0201 mg/kg
Metlakatla
0.0066 mg/kg
0.0066 mg/kg
0.31 mg/kg
0.31 mg/kg
Prince Rupert
0.0098 mg/kg
0.0098 mg/kg
0.0201 mg/kg
0.0201 mg/kg
Wiah Point
0.014 mg/kg
0.014 mg/kg
0.405 mg/kg
0.405 mg/kg
Armentieres Channel
0.0223 mg/kg
0.0223 mg/kg
0.0672 mg/kg
0.0672 mg/kg
Bischof Islands
0.0057 mg/kg
0.0057 mg/kg
0.0788 mg/kg
0.0788 mg/kg
Haswell Bay
0.0069 mg/kg
0.0069 mg/kg
0.0695 mg/kg
0.0695 mg/kg
Louscoone Inlet
0.0132 mg/kg
0.0132 mg/kg
0.0188 mg/kg
0.0188 mg/kg
Bella Bella
Not analyzed
0.0254 mg/kg
0.0254 mg/kg
Port Neville
0.007 mg/kg
0.007 mg/kg
0.15 mg/kg
0.15 mg/kg
Sechelt
Not sampled
0.9 mg/kg
0.9 mg/kg
Strait of Georgia 1
Not sampled
0.92 mg/kg
0.92 mg/kg
Strait of Georgia 2
Not sampled
0.615 mg/kg
0.615 mg/kg
Howe Sound 1
Not sampled
0.019 mg/kg
0.019 mg/kg
Howe Sound 2
0.005 mg/kg
0.005 mg/kg
1.28 mg/kg
1.28 mg/kg
Howe Sound 3
0.0082 mg/kg
0.0082 mg/kg
0.0351 mg/kg
0.0351 mg/kg
Indian Arm 1
0.0067 mg/kg
0.0067 mg/kg
0.0217 mg/kg
0.0217 mg/kg
Indian Arm 2
0.0087 mg/kg
0.0087 mg/kg
0.246 mg/kg
0.246 mg/kg
Burrard Inlet 1
0.0044 mg/kg
0.0044 mg/kg
0.131 mg/kg
0.131 mg/kg
Burrard Inlet 2
Not sampled
0.0209 mg/kg
0.0209 mg/kg
Burrard Inlet 3
0.0071 mg/kg
0.0071 mg/kg
0.0282 mg/kg
0.0282 mg/kg
Burrard Inlet 4
0.0056 mg/kg
0.0056 mg/kg
0.205 mg/kg
0.205 mg/kg
Burrard Inlet 5
Not sampled
0.0884 mg/kg
0.0884 mg/kg
Burrard Inlet 6
0.006 mg/kg
0.006 mg/kg
0.157 mg/kg
0.157 mg/kg
Burrard Inlet 7
Not sampled
1.95 mg/kg
1.95 mg/kg
Burrard Inlet 8
0.0079 mg/kg
0.0079 mg/kg
Not sampled
Burrard Inlet 9
0.0095 mg/kg
0.0095 mg/kg
0.98 mg/kg
0.98 mg/kg
Burrard Inlet 10
0.0131 mg/kg
0.0131 mg/kg
1.54 mg/kg
1.54 mg/kg
Burrard Inlet 11
Not sampled
1.58 mg/kg
1.58 mg/kg
Burrard Inlet 12
Not sampled
0.6 mg/kg
0.6 mg/kg
Burrard Inlet 13
Not sampled
1.22 mg/kg
1.22 mg/kg
Burrard Inlet 14
Not sampled
Not sampled
Burrard Inlet 15
0.015 mg/kg
0.015 mg/kg
0.029 mg/kg
0.029 mg/kg
Fraser River 1
0.0093 mg/kg
0.0093 mg/kg
0.68 mg/kg
0.68 mg/kg
Fraser River 2
Not sampled
0.69 mg/kg
0.69 mg/kg
Fraser River 3
Not sampled
0.97 mg/kg
0.97 mg/kg
Fraser River 4
Not sampled
0.9 mg/kg
0.9 mg/kg
Fraser River 5
Not sampled
Not sampled
Fraser River 6
0.0143 mg/kg
0.0143 mg/kg
Not sampled
Fraser River 7
0.0153 mg/kg
0.0153 mg/kg
0.0314 mg/kg
0.0314 mg/kg
Tsawwassen
Not sampled
0.0216 mg/kg
0.0216 mg/kg
Lemmens inlet
Not sampled
0.0252 mg/kg
0.0252 mg/kg
Grice Bay
Not sampled
0.0658 mg/kg
0.0658 mg/kg
Dixon Island
0.0053 mg/kg
0.0053 mg/kg
0.0242 mg/kg
0.0242 mg/kg
Saturna Island
Not analyzed
Not detected
Fulford Harbour 1
0.0045 mg/kg
0.0045 mg/kg
Not detected
Fulford Harbour 2
0.0054 mg/kg
0.0054 mg/kg
Not detected
Patricia Bay
0.0039 mg/kg
0.0039 mg/kg
Not detected
Finnerty Cove 1
Not analyzed
Not detected
Finnerty Cove 2
Not sampled
0.721 mg/kg
0.721 mg/kg
Victoria Harbour 1
Not sampled
1.3 mg/kg
1.3 mg/kg
Victoria Harbour 2
0.0177 mg/kg
0.0177 mg/kg
0.745 mg/kg
0.745 mg/kg
Victoria Harbour 3
Not sampled
0.392 mg/kg
0.392 mg/kg
Victoria Harbour 4
0.0112 mg/kg
0.0112 mg/kg
Not detected
Albert Head 1
0.0234 mg/kg
0.0234 mg/kg
Not detected
Albert Head 2
Not sampled
South

What is it?

Mercury is found in the Earth’s crust predominantly in the form of mercuric sulphide (cinnabar). It can enter the environment through both natural and anthropogenic sources.  Natural sources include forest fires and volcanoes, while major anthropogenic sources include coal burning, metals smelting, gold and silver mining, and chlor-alkali production.1 In addition, mercury that has been deposited in the past can be re-emitted into the atmosphere.

In Canada, chlor-alkali plants were the largest source of anthropogenic mercury until the 1980s. Emissions have declined as a result of initiatives to move away from mercury-based processes and plant closures.1 In the 1990s, the mining and smelting industries became the largest contributors of anthropogenic mercury emissions, although emissions have been decreasing since the mid-1990s. As of 2010, electricity generation accounted for 30% of mercury emissions to the atmosphere in Canada.1

FACT: An estimated 200 tonnes of mercury are deposited in the Arctic each year, largely via atmospheric transport. A ten-fold increase in mercury levels in certain Arctic wildlife species has been observed over the past 150 years.2

How does it get into the ocean?

Mercury is distributed through the environment primarily via atmospheric transport.3 It circulates until it is removed, mostly by rainfall. Because it can be transported long distances in the atmosphere, it is found even in remote areas, including the High Canadian Arctic.3 Transport of mercury can also occur in river sediments and along ocean currents.

Methylmercury, the organometallic form of mercury, is the main form of mercury that is absorbed by fish and wildlife.4 It enters marine food webs via algae and bacteria, and is then transferred to zooplankton, then to benthic invertebrates, and so on up the food chain.4

Is it a problem?

Methylmercury is the form of mercury that is of greatest concern from a toxicological standpoint.5 Methylmercury biomagnifies (increases in concentration in the tissues of organisms as it moves up the food chain) and distributes into various organs in the body, including the brain. It can also be transferred from mother to young in both mammals and birds.5,6 Its tendency to biomagnify and accumulate in tissues poses potential health risks for top marine predators as well as humans who consume seafood.5

In terms of effects, methylmercury is well known for its neurotoxicity, with more severe symptoms including anorexia, loss of coordination, and eventual death.5 It can also be toxic to the immune, endocrine and reproductive systems.7

On a population level, methylmercury toxicity has been associated with decreased reproductive success in North American common loons, with decreases in productivity of at least 50% in some cases.8,9 Specific effects include reduced clutch sizes, increased rates of embryonic deformity and mortality, and reduced hatching success.5

What is being done?

In Canada, regulations prohibit the manufacture and import of products containing mercury or any of its compounds, with exemptions for essential products that have no viable alternatives.10

Marine water and sediment quality guidelines are available for mercury. Water quality guidelines are based on toxicity data for fish, invertebrates, and plants, while sediment guidelines are derived from toxicity endpoints in benthic invertebrates. A tissue residue quality guideline for the protection of wildlife consumers of aquatic biota exists for methylmercury.

Health Canada sets a maximum level for mercury in fish tissue consumed by humans.

What can we do?

As individuals and organizations, we can:

  • Learn more about mercury, methylmercury and other toxic metals using the resource links below
  • Recycle and dispose of waste responsibly and according to local guidelines

More Information?

1 Environment and Climate Change Canada. 2016. Canadian Mercury Science Assessment: Summary of Key Results. Environment and Climate Change Canada, Gatineau, QC. 46 pp.

2 UNEP. 2013. The Global Mercury Assessment 2013: Sources, Emissions, Releases and Environmental Transport.

3 Environment and Climate Change Canada 2013. Mercury: Atmospheric Transport. Environment and Climate Change Canada, Gatineau, QC. https://www.ec.gc.ca/mercure-mercury/default.asp?lang=En&n=54E48CBE-1

4 Braune B, Chételat J, Amyot M, Brown T, Clayden M, Evans M, Fisk A, Gaden A, Girard C, Hare A, Kirk J, Lehnherr I, Letcher R, Loseto L, Macdonald R, Mann E, McMeans B, Muir D, O’Driscoll N, Poulain A, Reimer K, Stern G. 2015. Mercury in the marine environment of the Canadian Arctic: Review of recent findings. Science of the Total Environment 509-510: 67-90.

5 Scheuhammer A, Braune B, Chan HM, Frouin H, Krey A, Letcher R, Loseto L, Noël M, Ostertag S, Ross P, Wayland M. 2015. Recent progress on our understanding of the biological effects of mercury in fish and wildlife in the Canadian Arctic. Science of the Total Environment 509-510: 91-103.

6 Noël M, Jeffries S, Lambourn DM, Telmer K, Macdonald R, Ross PS. 2016. Mercury accumulation in harbour seals from the Northeastern Pacific Ocean: The role of transplacental transfer, lactation, age, and location. Archives of Environmental Contamination and Toxicology 70: 56-66.

7 Frouin-Mouy H, Loseto LL, Stern GA, Haulena M, Ross PS. 2012. Mercury toxicity in beluga whale lymphocytes: Limited effects of selenium protection. Aquatic Toxicology 109: 185-193.

8 Evers DC, Savoy LJ, Desorbo CR, Yates DE, Hanson W, Taylor KM, Siegel LS, Cooley Jr. JH, Bank MS, Major A, Munney K, Mower BF, Vogel HS, Schoch N, Pokras M, Goodale MW, Fair J. 2008. Adverse effects from environmental mercury loads on breeding common loons. Ecotoxicology 17:69–81.

9 Burgess NM, Meyer MW. 2008. Methylmercury exposure associated with reduced productivity in common loons. Ecotoxicology 17:83–91.

10 Environment and Climate Change Canada. Products containing mercury regulations (SOR/2014-254). Available at: http://ec.gc.ca/lcpe-cepa/eng/regulations/DetailReg.cfm?intReg=203

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