Species Habitat

Habitat & Species

Prev Indicator
Water Quality

Aquatic habitat and species in the Athabasca 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. Less healthy fish with deformities and tumours and mass fish die-offs in some lakes have been observed by Indigenous communities and local residents of the middle and lower Athabasca watersheds. Studies based on scientific and local knowledge observations have documented elevated mercury concentrations in fish in the lower Athabasca. In the Peace-Athabasca Delta, a significant decline in muskrat (Ondatra zibethicus) populations and mass die-off events have been documented by scientists, elders and trappers, linked to increased contamination and changes in hydrologic patterns in the Delta. Scientific or Indigenous Knowledge observations of changes in wetland cover or riparian forests in the sub-basin were not found.

The following table summarizes the availability of information for each Habitat and Species indicator.

Signs and Signals

Indigenous Knowledge Information and Data

Indigenous Knowledge Availability in Public Sources1

Science Information and Data

Science Data Availability2


Oral histories and local observations of fish abundance, timing and distribution, species diversity and fish health condition.

Local observations about changes in timing of local fishing activity and yield.

Many observations from several locations.

Fish (including salmon, suckers, pickerels, burbot) abundance, timing and distribution, species diversity and fish health condition.

Many data on fish population and health.


Oral histories and stories of wetland and forest (and other habitat / land use)

Local observations and oral histories of number, location and total area of wetlands

Some observations from few locations.

Number, location and total area of wetlands. Species diversity in wetlands where available.

Wetland mapping available from a variety of sources.

Scientific information on muskrat and beaver populations was not gathered for this report.

Riparian Forests

Local observations and oral histories of riparian forests

No information found.

Number, location, total area of riparian forests areas. Species diversity of riparian forests where available.

Limited information found.

1 Qualifiers for the availability of local and Indigenous Knowledge observations in publicly available sources: Limited = 1-2 observations; Some = 3-4 observations; Many = 5 or more observations
2 Qualifiers for the availability of science data in publicly available sources: Low = Individual studies or locations; Many = Network of monitoring stations across the basin


Declines in some fish populations and health condition have been observed by Indigenous communities and local residents in the Athabasca sub-basin.

Fish are reportedly less healthy and mass fish die-offs have been observed in lakes in the lower and middle Athabasca. Mikisew Cree community members participating in a community-based monitoring program have observed more deformities and tumours in fish collected from traditional use areas such as the Quatre Fourches and Jackfish areas of the Peace-Athabasca Delta.[79] Smaller fish and fish with deformities have been observed in lakes and rivers by Denesuline elders from Black Lake and Fond du Lake, which the elders associate with the disruption of fish habitat by mining exploration in the region.[80] Lower fish health compared to upstream baseline conditions were also found by the Joint Oil Sands Monitoring Program in the lower MacKay River, Ells River and in the Athabasca River below the Muskeg River, above the Ells River and below the Firebag River.[81]

Mass fish die-off events have been described by Indigenous communities and stewardship groups in some lakes in the lower Athabasca.[82],[83] An increase in the frequency of blue-green algae blooms has been noted in recent years by residents of Baptiste and Island Lakes, raising concerns for the impacts on fish populations.[84]

Dene Elders have observed smaller fish in lakes and rivers as well as deformed fish and new species,

Parlee et al., 2020

Denesuline elders from Black Lake and Fond du Lake have observed a rebound in the fish population in Lake Athabasca following the Government of Alberta’s closure of the commercial fishery for the lake.[85]
Mercury concentrations are higher than normal in some fish populations in the lower and middle Athabasca. A study of water and sediment quality in the area of Fort Chipewyan, Alberta determined that mercury levels in walleye (Sander vitreus) and most whitefish exceeded subsistence fisher guidelines for mercury. The study considered scientific and Indigenous Knowledge of fish abnormalities, concluding that together these observations “indicate that rates of fish abnormalities may be higher than expected, may be increasing, and may be related to declines in water quality.”[86] To manage the health risk posed by contaminated fish, recommended consumption limits have been derived based on measured mercury levels in fish in Alberta water bodies. Fish consumption limits provided by the Alberta government include limits for several waterbodies in the Athabasca sub-basin, such as Lake Athabasca, Chenal de Quatre Fourches, the lower Athabasca River, Namur (Buffalo) Lake, Clearwater River, Christina Lake, Lac La Biche, Baptiste Lake, and Lesser Slave Lake.[87]
The Eastern Athabasca Regional Monitoring Program is conducted in the lower Athabasca watershed, downstream of watersheds within which uranium mines and mills operate, in the Province of Saskatchewan. Results show that fish tissue chemistry, water chemistry, sediment chemistry, and benthic invertebrate community endpoints were similar to baseline, below guidelines, and/or within the reference range of the region.[88] For example, the levels of chemicals assessed in the fish collected from the communities from 2011 to 2018 in Lake Athabasca, Black Lake, Wollaston Lake, and Stony Rapids were considered low based on the human health risk assessment. The consumption of fish did not present health risks to Athabasca Basin residents and were considered in the study as safe to eat.[89]
Trout-perch (Percopsis omiscomaycus) was used to evaluate the potential exposure of fish to contaminants such as polycyclic aromatic hydrocarbons (PAHs). Level of change compared to baseline was assessed as “High” at test reaches below the Firebag River and above the Ells River; “Moderate” at baseline reaches at Poachers Landing, above Fort McMurray, below Fort McMurray at Northlands, and at test reaches below the Muskeg River and near the Athabasca River Delta; and “Negligible or Low” at the test reach above the Muskeg River.[90] Slimy sculpin (Cottus cognatus) showed consistent changes in downstream sections of the Steepbank River with-in the oil sands deposit in 2010 through 2013. These differences were indicative of exposure to polycyclic aromatic compounds.[91]
Arctic grayling (Thymallus arcticus) and bull trout (Salvelinus confluentus) abundance and population structure have declined significantly across its native range in Alberta, including streams and rivers in the Athabasca sub-basin (see Figure here for bull trout and Figure in Peace sub-basin for Arctic grayling). Both are listed as “Species of Special Concern” in Alberta. As a result, Alberta Environment and Parks set the fisheries management objective for arctic grayling as “conservation, recovery and restoration” and a detailed conservation management plan has been developed for bull trout.[92] Both species are “catch and release” province-wide.

Bull trout historic and current adult densities across its native range in Alberta. Available from Alberta Environment and Parks website.[93]

The Athabasca rainbow trout (Oncorhynchus mykiss) is genetically and physically distinct from the non-native rainbow trout.  A multi-stakeholder recovery team assembled by Alberta Environment and Parks prepared a recovery plan for this species. The goal of this recovery plan is to increase the number of Athabasca rainbow trout populations in low risk categories by a minimum of 10 per cent and to reverse the trend of an increasing number of populations in high risk categories.[94]

Wetlands & Riparian Forests

Wetland cover in the Athabasca sub-basin is small, and information on changes over time in wetlands in the sub-basin is limited. Notably, the Peace-Athabasca Delta, a globally-significant wetland, has become drier in the past century and Indigenous communities have observed a significant decline in muskrat (Ondatra zibethicus) populations in the Delta.

A sharp decline in muskrat (Ondatra zibethicus) abundance in the Peace-Athabasca Delta has been observed by a research team of scientists and elders and trappers from Mikisew Cree First Nation, Athabasca Chipewyan First Nation, and Fort Chipewyan Métis Local #125.[95] Lower water levels, changing flooding patterns and contamination from upstream hydroelectric development and oil sands projects are thought to be contributing factors to the muskrat die-offs observed at various times of the year in the Delta.[96] The environmental factors driving the drier conditions are a topic of much debate. However, a considerable body of research based on natural historical records preserved in lake sediments and tree rings indicates that drying of the Delta is driven by changes in local climate and a long-term decline in discharge of eastward-flowing rivers draining the Rocky Mountains and foothills.[97]

Elders and Indigenous land users in the Peace-Athabasca Delta (PAD) have observed a dramatic decline in the relative abundance of muskrat in recent decades (~1935–2014),

Straka et al., 2018

Ecological and Cultural Significance of the Peace-Athabasca Delta

The Peace-Athabasca Delta (PAD) occurs at the confluence of the Peace and Athabasca Rivers on a land base of approximately 3900 km2 in northern Alberta and the Northwest Territories. The PAD consists of a dynamic ecosystem of rivers, lakes, channels, marshes and grasslands that support a diversity of fish and wildlife. Wetlands in the PAD support approximately 45 species of mammals, 214 species of birds, and 20 fish species. As one of the largest inland freshwater deltas in the world, the PAD is designated as a Ramsar site, or a Wetland of International Significance. Approximately 80% of the PAD lies within Wood Buffalo National Park, a designated World Heritage Site.[98]

The Peace-Athabasca Delta is the ancestral homeland of the Cree, Chipewyan and Métis peoples and has sustained their traditional cultures and ways of life for generations. Waterways in the PAD provide a vast network of water transportation routes that enable traditional land users to access preferred harvesting areas, cabins, campsites, and other cultural use areas. Wildlife populations of fish, furbearers, mammals and waterfowl and many types of vegetation continue to provide for subsistence, material and cultural uses. Moose (Alces alces), muskrat (Ondatra zibethicus), walleye (Sander vitreus), whitefish, and jackfish are a few of the many species of cultural significance to local Indigenous communities.[99]

Before the rise of industrial development, ice jams in the springtime would cause the Peace and Athabasca rivers to overflow their banks and flood the Peace-Athabasca Delta, replenishing the landscape and perched basins with fresh water. Perched basins are high-elevation catchment areas that are solely replenished by overland flooding. When filled with water, perched basins in the Peace-Athabasca Delta provide quality wildlife habitat. Yet in the absence of ice jams and with lower water levels and changing flow patterns in the Delta, many of these perched basins are drying up. These changes diminish the quality of aquatic habitat and lead to displacement of wildlife populations (such as muskrat, beaver (Castor Candensis) and moose) from the region.[100]

Documented sources of Indigenous Knowledge or scientific information regarding changes in riparian forests the Athabasca sub-basin were not found.
Richardson Lake in the Peace-Athabasca Delta. Photo by Megan Spencer.

 Richardson Lake in the Peace-Athabasca Delta. Photo by Megan Spencer.


Land cover data indicates that 353 km2 of wetland was lost between 1990 and 2010 in the Athabasca sub-basin. This represented a 1% decline in wetland area, although the total percentage of wetland land cover in the basin only decreased from 17.2% to 17.0%. Comparable datasets for wetland area for the more recent period (2010-present) were not found.

Change in Wetland Cover in the Athabasca Sub=basin 1990 to 2010 (Agriculture and Agri-Foods Canada)[74]

Land Cover Type

Area 1990 (km2)
Area 2010 (km2)
Change (km2)

Change (%)

1990 % cover

2010 % cover

Forest Wetland







Treed Wetland














Wetland Shrub







Wetland Herb







Total Wetland







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Health & Wellbeing