top of page

Mercury Bioaccumulation - A Global-Scale Problem 

Mercury in the top 100 meters of the Earth's oceans has doubled

and 

increased by 25%

in deeper waters

(UNEP, 2013)

More than

3 billion people depend on ocean fish as their primary source of protein

(UNEP, 2013)

The use of mercury for 
gold mining is the largest source of mercury to the
global system

(UNEP, 2013)

Global Mercury Emissions 2010

(UNEP, 2013)

Mercury has a global cycle similar to the hydrologic cycle

UNEP, 2008

  • Mercury evaporates and is released as emissions via the burning of fossil fuels such as coal, as well as re-released by fire (UNEP, 2013).  

  • Mercury travels long distances in the atmosphere then gets deposited via wet and dry deposition (Stricherz, 2005) (UNEP, 2013).

  • Mercury moves through watersheds in many pathways, the main one being water as sediment (Domagalski et al. 2004).

  • Mercury is a Heavy Metal

  • Mercury exists in many forms but most commonly in nature as the mineral Cinnabar (mercury sulfide - HgS)

  • Cinnabar is mined for the mercury that is within it. The mine waste and mining processes release mercury to the environment.

Metacinnabar

(HgS) 

Cinnabar

(HgS)

Mercury

(Hg)

Mineral Photos: https://geology.com/minerals/cinnabar.shtml and http://www.sickinsight-online.com/

Watersheds are a Major Element

of the

Global Mercury Cycle

and Play a Major Role in Transformation of Mercury to its Toxic form

Methylmercury

Graphic: https://pubs.usgs.gov/fs/1995/fs216-95/

  • Mercury in its elemental form (Hg) is transformed to its organic, most toxic form, methylmercury (MeHg) by sulfate-reducing bacteria in aquatic environments.

  • Methylmercury is able to be taken into the tissues of biological organisms through the food web (Alpers et al., 2005).

  • Mercury biomagnifies as it transfers to subsequent trophic levels

    • Species at the top of the food chain end up with the greatest concentrations of mercury such as birds of prey and humans. ​

Graphic Source: https://themercurysite.com/caddo-lake/biomagnification/

Mercury is a potent neurotoxin that threatens humans and wildlife!!

Check out the Story Map of mercury in California

References for this page:

Alpers, Charles N., Michael P. Hunerlach, Jason T. May, and Roger L. Hothem. 2005. “Mercury Contamination from Historical Gold Mining in California.” Government. USGS. 2005.

​

Domagalski, Joseph L., John Clinkenbeard, Darell G. Slotten, Charles N. Alpers, Thomas H. Suchanek, Ronald Churchill, Nicolas Bloom, and Ayers, Shaun A. 2004. “Summary and Synthesis of Mercury Studies in the Cache Creek Watershed, California, 2001--01.” pubs.usgs.gov/wri/wri034335/wri_034335.pdf.

​

Stricherz, Vince. 2005. “Mercury Travels far from Source through Atmosphere, Study Shows.” Washington University, 2005, sec. News and Information.

​

UNEP. 2013. “Global Mercury Assessment 2013 Sources, Emissions, Releases and Environmental Transport.” Global Mercury Assessment. United Nations Environment Programme. http://www.unep.org/PDF/PressReleases/GlobalMercuryAssessment2013.pdf.

bottom of page