How will open-pit coal mining affect resident elk populations in Alberta?

The front ranges in southwest Alberta, colloquially referred to as the Eastern Slopes, have been garnering significant attention lately.  What began as the current provincial government quietly rescinding the 1976 Peter Lougheed Coal Policy has turned into public outcry seeking federal support. A steel monolith was even erected to attract public attention. Concerns have been raised regarding the potential long-term effects of open-pit coal mining practices, primarily the risk of contaminating a large water supply. 

Sitting just north of newly protected Castle Wildland Provincial Park, the southern tip of Alberta’s Eastern Slopes lies west of the Oldman Reservoir, part of a watershed that feeds a large region in southwest Alberta.  There are serious concerns regarding Selenium (a by-product of coal mining) leaching into groundwater and its effects on native trout species. While the health of the water supply is likely the largest concern, how might these open-pit practices affect other aspects of the ecosystem, particularly other animals?

In many habitats, elk act as a keystone species, meaning their “effects on the composition of communities are greater than one might expect based on their abundance.” Changes in their populations or behaviour not only cascade up and down the trophic levels but can even shape the morphology of the landscape. The animation below shows elk activity surrounding the Eastern Slopes over a period of six years.  171 elk were tracked from 2007-2012, giving a representative sample of migration habits for multiple herds in the region.

This gives us a good overview of the annual movement patterns in and around the Eastern Slopes.  We can see there are multiple herds that pass through the range on a regular basis.  If you watch carefully, you can pick out seasonal patterns.

These elk typically spend the summers up in alpine environments, where food is ample, and the added elevation offers increased visibility to spot predators.  They descend the front ranges into the prairies in the fall to rut and spend the winter at these lower elevations where access to food is easier during the snow-covered winter months.

Would mining activity on the Eastern Slopes disrupt this behaviour?  The map above shows a six-year footprint of the elk’s total coverage, coloured by season. This gives us an overview of their seasonal migration habits.

Seasonal patterns become obvious – spending the winter in the prairies in the east, and retreating into the heart of the Eastern Slopes during summer.  What’s interesting is there appears to be a select few corridors that the elk use, connecting the east and west sides of the range.  Will invasive open-pit activities disrupt this?  Are elk acting as a keystone species contributing to this ecosystem in ways we don’t yet realize?

If you found any of this interesting, Google Eastern Slopes Coal Mining and seek out sources which you deem credible.