Background

The oilsands of NE Alberta has abundant oil reserves, but its heavy black viscous oil, termed bitumen, is expensive to extract and must be rigorously treated to convert it into an upgraded crude oil. Current oil prices per barrel have recently made it cost-effective for companies to extract and process the bitumen. SAGD (steam assisted gravity drainage) is the most common method used to extract this oil. Seismic and delineation drilling determine where and how much oil is present.  Steam is then used to heat and move the material through underground veins to an extraction area.  These operations must occur in the winter, when the ground is frozen and are strictly controlled by the Alberta government due to the sensitive nature of boreal forest.

Objectives

We are working in collaboration with the Chipewyan Prairie Dene First Nation, StatoilHydro Canada  and the Alberta provincial government to monitor impacts of the oil exploration on the caribou, moose and wolf living on oil sands lease areas in NE Alberta.

The caribou, moose and wolf are monitored because their large size and ranging behavior make them likely to be impacted by oil development activities.  The caribou is a species of particular concern because it is threatened in Alberta.   The moose offers a good comparison species because it is similar in size but differs in microhabitat and social structure.  The moose is a primary prey species of the Chippewa Prarie Dene First Nation.  The caribou is a prey species of secondary importance to the Dene.  The wolf is the primary non-human predator of the moose and caribou.

We use detection dogs to comprehensively sample the study area for caribou, moose and wolf scat each year, beginning when the oil crews first arrive on site in December up until they pack up and leave in late March.

The comprehensive sampling provided by the dog teams allows us to simultaneously monitor:

• How population size changes for each species across years
• What factors in the environment each species is attracted to, or avoiding
• How do the stress, nutritional status and reproduction of each species vary over space—relative to distance from key resources and anthropogenic disturbances
• time—relative to intensity of extraction activities within and between years

We are also adding a low exposure control area where little or no oil extraction is occurring.

Methods

The monitoring began in January 2006, when the drilling exploration program started. The 2,500 km2 study area is divided into 46 contiguous 8 km x 8 km cells.  A 5 km x 5 km cell is placed within each cell in the best caribou and moose habitat.  The nested design simultaneously maximizes the number of individuals sampled and the resampling rate per individuals. Detection dogs are specially trained to detect scat from the study species in deep snow, over large remote areas.  The dog teams sample each 5 m x 5 km cell three times, once each at the start, peak and end of oil exploration activities each filed season.  This comprehensive sampling allows us to accomplish several complementary objectives. We determine the abundance and distribution of the moose, caribou and wolf through DNA-based mark-recapture analyses, using DNA extracted from fecal samples of these three species (Wasser et al 2004). We track long-term changes in survivorship over multiple years.  We measure spatial changes in resource selection patterns and physiological health, all in relation to distance from natural and anthropogenic features and temporal patterns in extraction activities.

Our physiological health measures partition the various pressures impacting these species as follows:

1. Cortisol:  Cortisol is an adrenal hormone secreted in response to many external stressors.  Elevated cortisol metabolites in feces indicate stress impacts, such as those  resulting from noise and other direct disturbances resulting from the rapid influx of human activities, as well as from reduced nutrition.  Toxin exposure blunts the cortisol response to acute stress.
2. Thyroid hormone concentration: Animals reduce thyroid hormones under nutritional stress to reduce metabolism, making their body more efficient at storing energy.  Low thyroid hormone levels thus reflect nutritional stress, implying reduced food availability. (Cortisol also tends to be elevated under nutritional stress, as cortisol releases internal stores of glucose for increased energy.)  Toxin exposure can suppress thyroid hormone.
3. Reproductive hormones—testosterone in males and estrogen and progesterone in females— reflect reproductive status as well as changes in sex-specific reproductive health that could be resulting from stress or toxin-related hormone disruption.

Results

Findings to date show that the hormone cortisol increases (reflecting mounting emotional or nutritional stress, or both) and thyroid hormone decreases (reflecting mounting nutritional stress) in wildlife scat as exploration activity increases. During the first year of study, those physiological measures recovered in moose and caribou as soon as the work crews started packing up to go home, but still well before spring arrives—suggesting that it’s not the renewal of food supplies that alleviate the animals’ stresses. Not so for the wolves: their nutritional and emotional stress levels increase right through the end of the season, suggesting that the disturbance makes it progressively more difficult for them to catch prey.

Caribou mostly prefer wetland, lichen-rich habitat, avoid high use roads, but have a slight preference other linear features such as cutlines” cleared for seismic mapping of tar-sands deposits, paths above underground pipelines, trails and uncleared roads.  They also avoid areas of clear-cuts and areas of high terrain complexity characterized by variation in elevation and edges between habitats.  This avoidance is likely related to predator avoidance behavior.  Moose, on the other hand, prefer areas that have high shrub and other browse content, including shrubby areas, clear-cuts, and burned areas.  Wolves have an exceedingly high preference for all linear features.  The attraction of caribou to linear features could increase their vulnerability to predation by the wolves also frequent linear features. Moose, by contrast, prefer good feeding grounds over linear features, a strategy that serves them well: thus far, hormones in their scat have indicated smaller nutritional deficits than in the other two species.

 

 

 

 

 

Implications

Assuming that Statoil and other contributing oil companies support this work for the duration of their leases, this would be the first time in history that oil extraction impacts on wide-ranging mammals were comprehensively monitored throughout their course of development. This will serve as a model to other oil companies, allowing potential impacts from oil extraction activities to be detected and mitigated in the most timely, cost-effective manner, while minimizing disruptions to operations.
Monitoring changes in the caribou, moose and wolf populations over time, and comparing values to control populations of the same species, will allow us to separate natural seasonal changes from those directly resulting from anthropogenic impacts.  This will increase our probability of detecting impacts quickly, allowing them to be mitigated before they become irreconcilable.
To the extent that climate change results from these practices, this study could also produce models that emulate long-term health and distribution impacts of climate change on wide-ranging wildlife on a broader scale.