Mercury (Hg) is an element that is naturally found in many rocks and minerals around the world. Mercury can be released into the environment through a number of processes, both natural and caused by human activity. Forest fires and flooding can release mercury, when rocks containing the element are disturbed and/or exposed.

Human activity is an increasingly prevalent cause of mercury release. As an example, coal-burning power generation facilities are the most common source of mercury in the environment1. In Alberta, the majority of mercury emissions are through the air2.

While mercury is a naturally-occurring element, it can be harmful to the environment and wildlife if it accumulates in a high enough concentration. In the environment, elemental mercury is converted naturally by bacteria into what is known as “organic” mercury, the most common of which is called methylmercury3. Methylmercury—what we are actually referring to when we think about mercury in the food chain— becomes a problem through a process called bio-accumulation4. Micro-organisms in water and soil consume methylmercury, which binds to and accumulates in their tissues. Small fish and wildlife then consume these microorganisms, and the mercury begins to accumulate in their bodies. As the mercury moves through the food chain, from microorganisms to small fish and animals to larger fish and animals, it reaches the highest concentrations in the bodies of larger, predatory animals. This bio-accumulation is why there are often health advisories that limit the amount of large predatory fish that should be eaten by people.


Depending on the size and age of an animal, mercury levels in their tissues can reach dangerous levels through this process. Exposure to high concentrations of mercury—absorbed through the digestive tract and accumulating in the tissue—can lead to a number of problems, including neurological issues, kidney and lung damage, and, ultimately, death.
The Environmental Monitoring and Science Division (EMSD) works in partnership with regional, provincial and federal entities to ensure adequate monitoring of mercury in Alberta’s environment. With so many questions about the impacts of resource development on mercury levels, EMSD aims to ensure that these levels are not only monitored accurately, but that information about the risk to human health is quickly and transparently communicated.


The Joint Canada-Alberta Implementation Plan for Oil Sands Monitoring (JOSM) is a science-based environmental monitoring plan that expands previous research and evaluation efforts. In Alberta, it is known that development of the oil sands disrupts the natural environment, and creates the potential for mercury to be released into the ground and water.

In addition to measuring the general environmental impacts of mercury on air, water and soil, JOSM focuses primarily on the oil sands region. JOSM goes beyond simply measuring mercury levels to track where the mercury is coming from, and chart its travel. Through this system, EMSD is able to monitor important wildlife populations in the region, specifically bird and fish species.

Monitoring in the Athabasca Region

The majority of oil sands activity in Alberta occurs north of Fort McMurray, along the Athabasca River and the Peace Athabasca Delta. This region is ecologically vulnerable, and acts as an important nesting and breeding ground for a number of bird and fish species. Examples of wildlife in the area include the Whooping Crane, an endangered species. Monitoring is done in the region to understand and mitigate the effects of oil sands development.

The First Nations and Métis people of the Athabasca region engage in fishing as an integral part of their cultural tradition. Therefore, monitoring mercury levels in the area is critical to minimizing their risk and maintaining this traditional way of life. EMSD works with local populations to monitor fish habitats in the region, and sample fish from areas of concern to local communities.

Birds are perhaps the best indicators of mercury levels in the Athabasca region, as they are top predators and through bio-accumulation their mercury levels tend to be highest. Monitoring has focused specifically on gull and tern populations; while migratory species, these birds obtain a majority of their nutrients from around the oil sands region. Their mercury levels are typically a good indicator of the mercury levels in the habitats around the oil sands. Eggs are monitored specifically, for three reasons:

  1. Adult birds do not tend to leave the breeding ground around the Athabasca region while nesting. This can support researchers’ measurements as any mercury in the resulting eggs is guaranteed to have come from a local source.
  2. Mercury levels in fish that the birds feed on can change rapidly. However, as breeding birds consume these fish, mercury levels in their eggs will reflect mercury levels in the general environmental in a timely fashion.
  3. Mercury levels in eggs can affect the development of young birds. By tracking these levels, scientists can ensure that the health of the young and developing bird populations remains protected.
1 Lane, K. (2012) “Dangerous Attractions: Mercury in Human History” in Mercury Pollution: A Transdisciplinary Treatment. Edited by Sharon L. Zuber and Michael C. Newman. Boca Raton: CRC Press, Taylor & Francis Group.
2 Hebert, C.E. et. al. (2013) “Mercury Trends in Colonial Waterbird Eggs Downstream of the Oil Sands Region of Alberta, Canada” Environmental Science and Technology 47: 11785-11792.
3 Agency for Toxic Substances and Disease Registry (ATSDR) (1999) Toxicological Profile for Mercury. U.S. Department of Health and Human Services.
4 Ibid.