Summary of Assessment
Moderate changes to aquatic ecosystem health have occurred in the Peel sub-basin, according to most indicators considered in the assessment. Climate change was identified as a key driver of aquatic ecosystem change in the sub-basin, resulting in changes to water quality and quantity related to permafrost thaw and slumping, and affecting access to traditional land use areas.
Water Quantity
- Warmer air temperatures have caused permafrost thaw and slumping.
- Increased groundwater discharge and higher fall precipitation have led to higher annual and winter stream flows, while land users have observed drying in some areas.
Habitat & Species
- Overall fish are plentiful, but some fish populations and signs and signals of fish health have declined as reported by traditional harvesters.
- In some areas, a rise in otter and beaver populations alongside a significant decline in muskrat populations has been documented.
Water Quality
- Increased suspended sediments and levels of certain salts and metals in surface waters.
- Warmer water temperatures observed by Indigenous communities.
Health & Wellbeing
- Changes in aquatic ecosystems have resulted in reduced confidence in country foods and reduced access to traditional land use areas.
Water Quantity
- Warmer air temperatures have caused permafrost thaw and slumping.
- Increased groundwater discharge and higher fall precipitation have led to higher annual and winter stream flows, while land users have observed drying in some areas.
Water Quality
- Increased suspended sediments and levels of certain salts and minerals in surface waters.
- Warmer water temperatures observed by Indigenous communities.
Habitat & Species
- Overall fish are plentiful, but some fish populations and signs and signals of fish health have declined as reported by traditional harvesters.
- In some areas, a rise in otter and beaver populations alongside a significant decline in muskrat populations has been documented.
Health & Wellbeing
- Changes in aquatic ecosystems have resulted in reduced confidence in country foods and reduced access to traditional land use areas.
People & Places
The Peel sub-basin is the smallest and northernmost sub-basin in the Mackenzie River Basin. The sub-basin is primarily accessed on a seasonal basis for subsistence harvesting, tourism, and outdoor recreation. The traditional territories of at least seven Indigenous groups overlap with the sub-basin. The Mackenzie River Delta and the surrounding region spans the lands of the Inuvialuit and Tetlit Gwich’in, with communities based in Fort McPherson and outside the sub-basin at Aklavik, Inuvik, and Tsiigehtchic. The Vuntut Gwichin lands are located in the region surrounding Old Crow, while the lands of the Tr’ondëk Hwëch’in and Na-Cho Nyäk Dun are primarily located further south, near Dawson City and Mayo, respectively.
Water quantity in the Peel sub-basin has undergone moderate change. Observations by Indigenous communities and scientists suggest the sub-basin is subject to significant reductions in snow and ice cover, earlier ice break-up and later freeze-up, and more variability in water levels in lakes, rivers, and creeks although levels are generally lower than in the past. These changes are largely the result of the effects of climate change over the past few decades, such as rising air temperatures and more precipitation events. Human water use within the sub-basin has no significant consequences on water quantity due to the small population. Annual average river flows have mostly been stable, but winter and spring river flows have increased by up to 2% per year. Changes in water quantity threaten to further disrupt the aquatic ecosystem health and the ability for Indigenous communities to practice traditional land uses in the sub-basin.
Read more about Snow & Ice, Water Flows & Levels, Climate and Water Use
Changes in water quality have been observed in parts of the Peel sub-basin and have affected the ability of some Indigenous communities to practice traditional land uses. The Gwich’in and members of the First Nation of Na-Cho Nyäk Dun have observed warmer water temperatures than in the past, which they associate with observed declines in the health of some fish species. Observations by Indigenous communities and scientists indicate that permafrost thaw is accelerating across the glaciated terrain in the Peel sub-basin, as evidenced by a rise in observations of slumps and ‘holes’ in the earth, and erosion along the banks of streams and rivers. Permafrost thaw has led to an increase in sediment and solute loads in adjacent watercourses, leading to observations of muddy water in local waterbodies by the Gwich’in. Streams affected by such permafrost-slumping showed lower abundances of benthic invertebrates. The potential for industrial development in the sub-basin is a concern for local communities in the sub-basin as there is concern for how contaminants could affect water quality and ecosystem health.
Read more about Water Quality, Benthic Invertebrates, Land Use and Effluent Discharges
Aquatic habitat and species within the Peel sub-basin are undergoing moderate change. This assessment is based on observations of changes in the abundance and health condition of some fish and furbearer species as reported by Indigenous communities, as limited scientific data was found for Arctic fish stocks. Traditional harvesters have observed fish species that were formerly not present in the Peel sub-basin, along with an increase in pike populations. Stocks of some species are in decline, including some preferred salmonid species, although traditional harvesters generally describe healthy fish populations in the Peel sub-basin. Reports of less healthy fish with “softer” flesh and abnormalities have been made in recent years. In some areas, a rise in otter (Lutra canadensis) and beaver (Castor canadensis) populations alongside a significant decline in muskrat populations has been documented, attributed in part to declines in habitat quality for muskrats (Ondatra zibethicus) and increasing competition between furbearer species. Indigenous Knowledge and scientific observations of changes in wetland cover or riparian forests in the sub-basin were not found.
Changes in aquatic ecosystem health in the Peel sub-basin are having moderate impacts on the health and wellbeing of local Indigenous communities. Health and wellbeing are closely linked to access to country foods. Some traditional harvesters report consuming less fish than in the past in response to declines in fish stocks and concerns about potential contamination to water and fish from upstream sources. Similarly, other harvesters report a reduction in access to preferred fishing areas given the increased frequency of riverbank erosion, lower water levels and more sandbars forming in rivers. Gwich’in and Inuvialuit trappers have reported the disappearance of muskrat populations from the upper Mackenzie River Delta in the past 5 to 10 years, and as a result fewer people consume muskrat (Ondatra zibethicus) as part of their diet. The reduced quality and availability of country foods in the Peel sub-basin is viewed as having a negative impact on the health and wellbeing of indigenous communities as it limits opportunities to practice a traditional way of life and threatens the continuity of local cultures. A low availability of scientific data for levels of country food consumption was found.
