Caribou are unique in that they require vast amounts of space to access the other things they need to thrive: water, shelter, and food. But the landscapes of the Bathurst caribou herd’s seasonal ranges are changing as human activities and developments like mining expand, and as the climate warms. As caribou move across the land, they encounter many features such as roads, mines, camps, communities, and burned forests which, along with other factors, may create stress. Individual stressors on caribou can add up over time and interact in complex ways, making it even more difficult to determine what these cumulative effects on caribou might be.
The decline of the Bathurst herd from a high of around 450,000 caribou in the 1980s to only about 20,000 caribou today has raised concerns and questions about why the herd’s numbers are decreasing. A combination of things, from the productivity of vegetation caribou feed on, to predation rates and harvest, to insect harassment and weather, is likely involved. While there is no one reason for the recent declines, industrial activity such as mining is a likely contributor. What are the effects of development on caribou? How will existing and future exploration, mine development, and the roads and other infrastructure that accompany mining operations, affect the movements and size of the Bathurst herd? Research is underway to try to answer questions like these. Although there aren’t definitive answers yet, there is a desire to look at all the factors that may be at play in the caribou’s range, and to take action to manage the herd’s habitat and the cumulative effects of development there. Based on the Bathurst caribou’s current status, it’s essential to do everything possible to help the population recover.
As a result, a working group was put together to come up with a plan to manage human and natural disturbance across the Bathurst caribou’s habitat. Made up of representatives from Aboriginal governments and organizations, environmental organizations and industry, co-management boards including the WRRB, and territorial and federal governments, the working group has been working on drafting a Bathurst Caribou Range Plan during the last two and a half years. An interim discussion document is now ready for public review and comment. Karin Clark, Cumulative Effects Biologist with Environment and Natural Resources, GNWT, gave a presentation on the Range Plan at the Cumulative Impact Management Program (CIMP) workshop in Behchokǫ̀ January 31-February 1, and updated the Board at its February 2017 meeting.
The goal of the Range Plan is to develop a resilient landscape over a long time, able to recover quickly from disturbance and suitable for the Bathurst herd, whether it’s increasing or decreasing in its natural cycle. To manage the habitat in a way that can sustain these caribou in future, the Range Plan aims to maintain important caribou habitat, maintain connections between seasonal ranges so caribou can move from one area to another, and manage human use and activities. Finding ways to manage cumulative effects from land use and habitat disturbance is especially important during low cycles of abundance when caribou may be more vulnerable to human disturbance.
First, it was important to collect information from both traditional knowledge and science about the caribou’s habitat and what’s happening on the landscape now. The Working Group held a workshop and using maps, collected traditional knowledge on harvesting trails, the caribou’s migratory routes, water crossings, bridges between seasonal habitats, and other sensitive habitat areas. Traditional knowledge highlighted the importance of these features and where they are, and identified areas that are more important to the caribou seasonally. Scientific data also provided information on the caribou’s seasonal ranges and the caribou’s annual cycle. The Working Group then ranked the various habitats according to how sensitive each habitat is and the likely consequence of disturbance there would be to caribou. For example, calving and post calving range was ranged as very high in sensitivity to disturbance in spring. The tundra in fall was rated as Low. Caribou collar information reflected caribou’s use of various areas in its range, as well as avoidance of other areas. All the information was placed on one map so that it was possible to see highly sensitive and highly used areas, for example, as well as areas that are used less often by caribou and are less sensitive.
Range planning also involves looking into the future. What might the future look like so we can plan now and take appropriate action to protect the habitat for caribou? How can we look into the future? The Working Group took the approach of using scenarios. For example, how might things look on the Bathurst range in 2040? First, they mapped the current situation with various land use features including existing roads, active mine sites, and communities, and identified potential Zones of Influence (ZOI) around them. ZOI are areas where caribou might be influenced by disturbance and change their behaviour. Then, they envisioned three different scenarios. The first case projected a future scenario with continuing development at a rate that is the same as it is today. The second case involved a future scenario where the rate of development decreases and development happens at a slower pace. A third scenario considered what the range might look like if development increases at a faster rate than it is happening today. Although none of these maps are real, they are a reasonable display of what could happen.
The Working Group also graphed predicted population numbers for the herd from 2016 to 2040, under each of the scenarios, including the current situation. They considered two cases: the first, what might happen for an increasing herd; and the second, what might we see for a decreasing herd? As expected, for a decreasing herd, the numbers declined most rapidly and to the lowest point when development was happening at an increased rate. And correspondingly, when the herd was increasing, its numbers didn’t go up as quickly as the other scenarios when there was increased development.
These map projections can help managers think about what and how caribou might be respond to and be affected by interacting with these features. What happens when caribou encounter a mine site or road? What behaviour changes are there and what might that mean for the caribou population? What will their body condition be or their pregnancy rate?
Cumulative effects are the sum total of the many factors that appear to be stressing caribou. The Working Group used a computer tool to help them add up all these stressors to caribou and to predict how they might interact. “We assume a small amount of stress as a result of a mine results in more running and less feeding, based on the scientific literature and expert opinion,” Karin Clark said. When caribou interact with development, there is an “energetic cost” to the population –caribou expend more energy than they would normally –a response that seems to be related to the number of times the caribou encounter development. “If the population is increasing, development drops the herd a little but may not be a concern. But if it’s decreasing, the small amount of reduction in caribou could be a concern.” It’s possible that cumulative effects could add up and affect caribou condition and ultimately their ability to become pregnant and raise a calf, Karin noted.
Karin also presented a slide showing Bathurst caribou migration trails, based on Tłı̨chǫ traditional knowledge. The map showed the trails before the mines appeared on the range and after the mines –and how the migration routes have changed in that time.
How could the range plan work?
The Working Group came up with four possible approaches to managing the amount of disturbance on the Bathurst range. One involves setting up protected areas or conservation zones to protect important migration corridors and sensitive habitats, such as calving grounds and key water crossings. A second approach involves setting land use activity guidelines to temporarily stop or reduce activity when caribou enter an area of development. Reducing barriers to caribou, how and where roads are built, and controlling the timing and amount of traffic are measures that could be taken in a third approach that manages human access.
Setting limits on disturbance on the Bathurst range
A fourth approach involves setting thresholds on how much disturbance can take place. The Working Group used a spotlight approach and assigned a traffic colour according to assessed risk to caribou. They divided the Bathurst range into five areas and mapped the state of the range based on the level of disturbance in each area. The thresholds describe the amount of disturbance in an area as high, moderate or low; assess the level of disturbance as critical or high risk (Red), cautionary (Yellow), or desirable or low risk (Green); and recommend actions for each colour zone.
Range sssessment areas in the Bathurst caribou range planning area - from Bathurst Caribou Range Plan Interim Discussion Document, GNWT
For example, an area in the Green zone does not have a lot of development activity. Within that zone, it would be business as usual, continuing to use best practices to ensure disturbance is minimized and key habitats are maintained. Areas 1 (including the Bathurst caribou calving grounds) and 3 (north of Gamètì and Wekweètì to the southern shores of Great Bear Lake) are in the Green zone. Areas 2 (includes the four operating mines), 4 (including the Tłı̨chǫ communities, Yellowknife, Dettah and Lutselk'e and 5 (affected by wildfire disturbance) are in the Yellow zone. For “Yellow” zones, reducing the ZOI and applying new mitigation techniques to lessen impacts on caribou, are among the list of recommended actions.
Cumulative disturbance framework current status by range assessment area - from Bathurst Caribou Range Plan Interim Discussion Document, GNWT
Each approach has benefits and challenges. The GNWT has asked for public input and has put together a discussion paper with considerations and questions to guide discussion. For example, when is permanent protection of habitat appropriate and where? What is an appropriate zone around migratory corridors and water crossings where caribou should not be disturbed? Should wildfire be incorporated into disturbance thresholds in forested regions? Can disturbance thresholds provide balance between protecting caribou and providing for economic development?
What happens next?
The GNWT has been meeting with communities and organizations to share the draft range plan and to collect people’s comments. A plain language summary of the discussion paper and background information can be found by visiting the ENR website at http://www.enr.gov.nt.ca/programs/barren-ground-caribou/bathurst-caribou-range-plan. Comments, feedback or questions can be sent [email protected] by March 31, 2017.
The Working Group plans to develop a Draft Range Plan this summer 2017 and to complete the Plan by March 2018.