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Taiga Plains Ecozone+ Evidence for Key Findings Summary

Theme: Human/Ecosystem Interactions

Key finding 8
Protected areas

Theme Human/ecosystem interactions

National key finding
Both the extent and representativeness of the protected areas network have increased in recent years. In many places, the area protected is well above the United Nations 10% target. It is below the target in highly developed areas and the oceans.

Ecozone+ key finding: In 2009, 5.6% of the ecozone+ had a high level of protection, by far the largest protected area being Wood Buffalo National Park, established in 1922. There was little change in protected areas from 1922 to the early 2000s when several, mainly quite small, protected areas were established. Candidate protected areas have been identified for the Mackenzie Valley in response to the proposed pipeline development. The aim is to maintain ecological integrity by permanently protecting areas of relatively undisturbed and important wildlife habitat which would be managed as a network to provide as much connectivity between them as possible.

Protected areas in northern Canada are planned and managed to safeguard culturally important areas and maintain biodiversity and ecological processes.Reference 89 In the Taiga Plains Ecozone+, there was little change in protected area coverage from 1922 to the early 2000s. Settlement of some land claims in the ecozone+ and growing awareness of the need for protected areas in the face of oil and gas development led to protected areas studies and plans in the Northwest Territories (NWT) part of the ecozone+,Reference 90, Reference 91 with new protected areas being established starting in the early 2000s. Protected areas in BC and Alberta portions of the ecozone+, with the exception of Wood Buffalo National Park, are small. An example is Hay River Protected Area, a 23 km2 BC park (shown in the northeast corner of BC in Figure 19) that protects black spruce muskeg and wetlands of cultural significance to First Nations in the Fort Nelson region.

The approach in protected area planning in northern Canada in recent years is to focus on ecological integrity, designing protected areas to meet the needs of sensitive species and to maintain ecological processes.Reference 89 Along the Mackenzie Valley, this involves connecting wildlife corridors to establish a network of protected areas.Reference 91 This is partly accomplished with buffer zones, areas managed to serve as transition zones between core protected areas and lands or waters subject to development.Reference 92, Reference 93

Status

Overall, in 2009, 5.6% of the ecozone+ was protected through 28 protected areas of IUCN categories I-III, by far the largest protected area being Wood Buffalo National Park, established in 1922 (Figure 19 and Figure 20). The second largest is Caribou Mountains Wildland Park, an Alberta wilderness area established in 2001 adjacent to Wood Buffalo Park. IUCN categories I-III include nature reserves, national wildlife areas, wilderness areas, and other parks and reserves managed for conservation of ecosystems and natural and cultural features.Reference 94 In addition, 22 km2 of the ecozone+ (<0.01%) was protected through three category V and VI protected areas, categories that focus on sustainable use by established cultural tradition within the protected area.Reference 94 Eighteen protected areas not classified by IUCN category protect a further 1.4% of the ecozone+. The most recent of these were Sahyoue and Edacho protected areas, established in 2009.

Figure 19. Map of protected areas in the Taiga Plains Ecozone+
Map
Source: Environment Canada, 2009;Reference 95 data from the Conservation Areas Reporting and Tracking System (CARTS), v.2009.05, 2009Reference 96
Long description for Figure 19

This map shows the locations of protected areas in the Taiga Plains Ecozone+.  The large protected area in the southeast corner of the ecozone+ is Wood Buffalo National Park, which extends outside of the ecozone+ into Alberta. Other large protected areas include Edéhzíe and Saoyue and Edacho in the central part of the ecozone+ and the Gwich'in Land Use Plan Conservation Heritage/Conservation Zone in the north.  A number of smaller conservation areas are scattered through the southwest corner of the ecozone+.

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Figure 20. Growth of protected areas, Taiga Plains Ecozone+, 1922-2009

Data provided by federal, territorial and provincial jurisdictions, updated to May 2009. Only legally protected areas are included. IUCN (International Union for Conservation of Nature) categories of protected areas are based on primary management objectives (see text for more information). Names and establishment dates of the larger protected areas are shown. Note: the yellow “unclassified" category represents protected areas for which the IUCN category was not provided.

Graph
Source: Environment Canada, 2009;Reference 95 data from the Conservation Areas Reporting and Tracking System (CARTS), v.2009.05, 2009Reference 96
Long description for Figure 20

This bar graph shows the following information:

Growth of protected areas, Taiga Plains Ecozone+, 1922-2009.
Year Protection EstablishedCumulative area protected (km2)
IUCN Categories I-III
Unclassified
1922-197223,9370
1973-197423,9400
197523,9410
1976-198223,9420
1983-198523,9480
1986-199324,1810
1994-199524,4530
1996-199824,5720
1999-200025,4060
2001-200232,1830
2003-200432,1832,763
2005-200833,5582,763
200933,5588,263

The graph makes note of the creation of national parks which are responsible for most of the increases from 1922 to 2009. Wood Buffalo National Park was established in 1922, Caribou Mountains Wildland in 2001, Travailant Lake and Mackenzie/Tree River in 2003, Edéhzhíe in 2005 and Sahyoue and Edacho in 2009.

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Cultural and wildlife values are represented in the protected areas in the Taiga Plains that are proposed through the NWT Protected Areas Strategy. Areas were identified under a five-year plan for the Mackenzie Valley to accelerate selection of areas in the face of the proposed Mackenzie Gas Pipeline.Reference 90 Protected areas are also proposed to address specific biodiversity conservation concerns. For example, the conservation zone by Great Bear Lake (Edaį́į́la) that is included in the proposed Sahtu Land Use Plan is intended to protect parts of the summer, fall, and winter ranges for the Bluenose-East Caribou Herd,Reference 97 while Edéhzhíe is intended to protect important migratory bird habitat.Reference 91

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Key finding 9
Stewardship

Theme Human/ecosystem interactions

National key finding
Stewardship activity in Canada is increasing, both in number and types of initiatives and in participation rates. The overall effectiveness of these activities in conserving and improving biodiversity and ecosystem health has not been fully assessed.

Ecozone+ key finding: Stewardship in the ecozone+ is associated with aboriginal cultural and spiritual values, incorporated into land-use planning through, for example, community conservation plans. Public-private sector partnerships and national and international initiatives also contribute to stewardship of ecosystems.

Planning, co-management, and Traditional Knowledge

Stewardship in the Taiga Plains involves aboriginal people who are committed to stewardship through their cultural and spiritual values. These values are reflected in land-use planning which involves community-based development of conservation plans. Land-use planning in the Mackenzie Valley involves four settled land claims (Inuvialuit, Gwich’in, Sahtu, and Tlicho) as well as the Deh Cho Interim Measures Agreement. The Mackenzie Valley Resource Management Act (MVRMA) applies to the Gwich’in, the Sahtu Dene, and the Métis, but does not apply to the Inuvialuit Settlement Region. The MVRMA sets the framework for land-use planning through regional and valley-wide land and water boards.

An important feature of stewardship in the Taiga Plains Ecozone+ is the incorporation of Aboriginal Traditional Knowledge (ATK) into co-management and regulatory boards (for example, Gwich’in Renewable Resources Board, 2012Reference 98), into environmental assessments (for example, Mackenzie River Basin Board, 2010Reference 19), and into research and monitoring (for example, Eamer, 2006Reference 99 and Woo et al., 2007Reference 100). Much effort has gone into developing ways to incorporate ATK into decision making in the Taiga Plains (for example, Mackenzie Valley Environmental Impact Review Board, 2005Reference 101). An assessment of effectiveness of the use of ATK by the Mackenzie Valley Environmental Impact Review Board concluded that, while substantial and sincere efforts had been made in incorporating ATK into their practices, the board was limited in its capacity to fully incorporate it by the need to deal with complex regulatory issues.Reference 102

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Public-private sector partnerships

Stewardship initiatives are also undertaken through public-private sector partnerships. Ducks Unlimited, an international non-profit organization, recognizing the importance of the western boreal forest to waterfowl, started a stewardship program in the late 1990s aimed at wetland conservation.Reference 103 The program includes collection of baseline information on waterfowl habitat, including surveys of waterfowl, habitat mapping, and water quality analyses, as well as research to fill knowledge gaps. The information acquired is used in helping to set conservation priorities, through land-use management and practices and through development of protected areas, with the aim of establishing interconnected areas of wetlands. The project includes, where relevant, working with industry to develop industrial practices that conserve waterfowl habitat.Reference 103

There are four Ducks Unlimited boreal forest wetlands initiatives in the Taiga Plains, developed through partnerships with the forest industry (in British Columbia), government agencies, First Nations and Inuvialuit management boards and renewable resource councils, universities, and private foundations. Taiga Plains projects (Figure 21) are:

  • Fort Nelson: 35,000 km2; partners include the forest industry and the BC Ministry of Forestry;
  • Sahtu: 32,000 km2; reports completed 2003; partners include Government of NWT and the Sahtu Renewable Resources Board;
  • Middle Mackenzie: 52,000 km2; partners include Gwich’in and Sahtu renewable resource boards and the Government of the NWT; and
  • Lower Mackenzie: 34,000 km2: partners include renewable resource boards and committees for the Inuvialuit and Gwich’in, as well as the Government of the NWT.
Figure 21. Locations of four western boreal forest wetlands projects led by Ducks Unlimited
Map
Source: Ducks Unlimited Canada, 2012Reference 104
Long description for Figure 21

This map shows the locations of four Ducks Unlimited Canada boreal forest wetlands projects located in the Taiga Plains Ecozone+.  The Lower Mackenzie and Upper Mackenzie wetland sites are located in the Mackenzie Delta in northwest of the ecozone+. The Sahtu wetland project is located west of Great Bear Lake, and the Fort Nelson project is located in the southwest corner of the ecozone+, in British Columbia.

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National and international initiatives contributing to stewardship in the Taiga Plains

At the national and international scale, several relevant management and habitat plans exist, especially for birds. They are used as means to identify areas for nomination as protected areas, including Ramsar sites (see the key finding on Wetlands). Wiken et al., 2006Reference 105 estimated that approximately 6% of the 166,487 km2 of wetlands in the Taiga Plains (using the 1995 ecozone classificationReference 5) are protected through National Parks. The North American Waterfowl Management Plan, signed in 1986 and 1993 by the governments of Canada, the United States, and Mexico in response to the loss of wetlands and declines in waterfowl, was updated in 2004 and in 2007Reference 106 to include interim land withdrawals for protected areas in the Mackenzie Valley.

Other responses to declines in birds include voluntary partnerships such as Partners in FlightReference 107 and the North American Bird Conservation InitiativeReference 108 have been started and have drafted management plans to assign conservation priorities and list actions (for example, Partners in Flight physiographic region plans, North American Landbird Conservation Plan, and Framework for Landbird Conservation in Canada). These initiatives have no binding provisions but can be useful in identifying and setting priorities for areas for conservation.

Under the Species At Risk Act, critical habitat has to be defined for Endangered or Threatened Wildlife which, in the Taiga Plains includes boreal woodland caribou. In 2012, critical habitat for boreal caribou was identified in the Recovery Strategy for the Woodland Caribou (Rangifer tarandus caribou), Boreal population, in Canada.Reference 109

Key finding 10
Invasive non-native species

Theme Human/ecosystem interactions

National key finding
Invasive non-native species are a significant stressor on ecosystem functions, processes, and structure in terrestrial, freshwater, and marine environments. This impact is increasing as numbers of invasive non-native species continue to rise and their distributions continue to expand.

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Ecozone+ key finding: There is some incursion of non-native plant species, especially along roadways, in the Taiga Plains, with only a few species being moderately invasive. An invasive non-native forest insect, the larch sawfly, has spread to the ecozone+, with regionally significant outbreaks in the 1990s. Increasing access, development, and climate change are liable to increase the rate of introduction and spread of non-native species in terrestrial and aquatic environments.

Currently invasive non-native species are not a significant threat to biodiversity in the ecozone+. However, this situation could change with the introduction and spread of non-native species from increased development and climate change.Reference 110 Road travel is one of the most important pathways of introduction of non-native species to the ecozone+.Reference 111 Non-native species generally take hold after ecosystems have been disrupted, creating niches that the new species can exploit. Both the means of transport and the disruption to ecosystems are generally needed for invasive species to become established in terrestrial mainland ecosystems. In isolated habitats, such as lakes and islands, a transport mechanism alone may be sufficient. Roads remain uncommon in most parts of the ecozone+, but are likely to increase with proposed development, increasing the risk to the biota of the ecozone+ from invasive non-native species.Reference 111

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Plants

About 10% of plant species in the NWT are not native to the region, a proportion comparable with other northern and western jurisdictions, and only a few of these are moderately invasive.Reference 110 By 2010, 116 non-native plant species had been identified in the NWT, mostly near communities or along linear disturbances, such as roads and cut-lines. Yellow and white sweet clover (Melilotus officinalis and M. alba), which have spread along rivers in Alaska and the Yukon,Reference 112 are found north as far as Inuvik but, at least in the NWT, appear not to have spread beyond communities and roadways.

In BC, the Fort Nelson Invasive Plant Management Area has the lowest incidence of invasive plant species in the province. Non-native species have been identified and categorized by current status or whether they are at risk of entering the region. There are 12 species or groups of closely related species in northeast BC classified as highly competitive with an ability to spread rapidly. These include hawkweeds (Hieracium spp.), hound’s tongue (Cynoglossum officinale), and knapweeds (Centaurea spp.).Reference 113

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Forest pests

A few non-native forest insect pests have been introduced to the Taiga Plains, including the larch sawfly (Pristiphora erichsonil), a European species. First reported in western Canada in the 1930s, larch sawfly spread north to the Fort Nelson area in 1952.Reference 114 It continued its northward spread, attacking tamarack (larch) stands in the southern NWT part of the Taiga Plains since the late 1960s.Reference 115 An outbreak of larch sawfly that damaged tamarack appeared in the South Slave in the mid-1990s and quickly moved westward and northward. The outbreak only lasted one year in the Hay River area but persisted in the Norman Wells area for about seven to eight years, but at lower defoliation levels.Reference 115 An outbreak occurred in northwestern Alberta in 1996 to 1999, defoliating large tracts of tamarack.Reference 114

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Aquatic species

The community structure of a water-body influences the chances of a non-native species establishing itself.Reference 116 The aquatic ecology of the Taiga Plains may be especially vulnerable to invasive species as it has relatively few species. Increasing water temperatures are shifting distributions of some fish species northwards in eastern North America: for example, the smallmouth bass (Micropterus dolomieu), a predatory species that has been shown to change species assemblages and thus alter food webs.Reference 117 Warmer waters in the Taiga Plains will also likely provide conditions that non-native species introduced from south of the ecozone+ will thrive in and will alter distributions of aquatic species, with consequences for food webs.

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Key finding 11
Contaminants

Theme Human/ecosystem interactions

National key finding
Concentrations of legacy contaminants in terrestrial, freshwater, and marine systems have generally declined over the past 10 to 40 years. Concentrations of many emerging contaminants are increasing in wildlife; mercury is increasing in some wildlife in some areas.

Ecozone+ key finding: Some legacy contaminants are declining in fish in the ecozone+ but the trends are not clear or consistent with, for example, DDTs increasing in recent years in Mackenzie River burbot. Brominated flame retardants in fish increased sharply up to the mid-2000s and then dropped, based on limited sampling. Mercury levels are naturally high in the Mackenzie Basin and have increased in fish, including in the Mackenzie River and Great Slave Lake within the ecozone+. Changes in aquatic ecology related to climate change may be either accentuating or masking trends in some contaminants.

Contaminants are substances that are introduced into the environment through human activity. Some, like mercury, are naturally occurring but may be augmented through human activity to levels that could harm ecosystems and humans. Contaminants can harm species and ecosystems and impair ecosystem services. They can directly affect animals when present in their diets, for example by impairing reproduction. Contaminants can also become a health risk for humans who rely on animals that accumulate contaminants for food – particularly for aboriginal people with diets heavily reliant on marine mammals and fish.Reference 118 This key finding only covers contaminants that persist in the environment and accumulate in the tissues of plants and animals.

Persistent organic pollutants enter the atmosphere through evaporation or industrial emissions and return to the surface of the Earth after travelling great distances. These contaminants are then deposited through rain or attached to small dust particles, falling on snow, ice, rocks, and vegetation. As the snow melts, it carries the particles and pollutants into aquatic ecosystems.

“Legacy contaminants” are those that have been banned or restricted but are still widespread in the environment. Several persistent organic pollutants, including the pesticide DDT and the industrial chemicals PCBs and HCHs, are considered legacy contaminants.

“Emerging contaminants” are newer chemicals, or substances that have been in use for some time and have recently been detected in the environment – usually emerging contaminants are still in use or only partially regulated. Despite being banned or restricted, some of these substances persist at levels that may impair animal health in some populations of long-lived top predators.Reference 3 Brominated flame retardants, for example PBDEs, are one class of emerging contaminants that have been detected in the environment, even in remote locations, at increasing levels since the mid-1980s. Concentrations of some brominated flame retardants show signs of stabilizing or declining in the last few years in response to new regulation and reductions in their use.118 Other emerging contaminants include some pesticides and herbicides in current use.

Mercury is another contaminant that can accumulate in wildlife. Much of the mercury in marine and freshwater systems is from industrial sources such as coal burning – and mercury releases are increasing in parts of the world.Reference 119 Mercury levels in animals are highly variable and trends are mixed.Reference 118

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Mercury in the Mackenzie River Basin

Mercury in the Mackenzie River Basin has been a focus of study in recent years partly due to increasing concentrations of mercury detected in marine mammals in the Beaufort Sea, as well as detection of relatively high levels of mercury in fish in the northern part of the basin.Reference 120 Sources of mercury to the Mackenzie River were estimated by Carrie et al., 2012Reference 120 as:

  • weathering of sulfide minerals in the mountains in the western part of the river basin (about 78% of the total mercury flux);
  • erosion of coal deposits (about 10%);
  • atmospheric deposition (about 6%); and,
  • mercury bound up in organic matter (about 5%).

All mercury is not equally available to biota, however, and, while relatively small fractions, mercury deposited from the atmosphere and mercury bound up in organic matter may move into the food chain more readily than mercury from other sources.Reference 120 Mercury is magnified through the food chain and levels in predatory fish in many lakes in the basin sometimes exceed Health Canada’s guidelines.Reference 59

Discharge of the Mackenzie River has been increasing over the past 35 years, which will have directly increased the amount of mercury discharged to the Beaufort Sea by a small fraction.Reference 121, Reference 122 As well, the higher water levels erode banks, contributing to higher sediment and mercury loads. An increase in forest fires, one of the predicted impacts from global warming, will likely increase mercury runoff to the Mackenzie River because most of the mercury from atmospheric deposition accumulates in the organic matter in the upper layer of soil which is exposed to erosion following fire.Reference 122

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Trends in mercury and persistent organic pollutants in the Taiga Plains

Mercury increased in lake trout and burbot from both east and west areas of Great Slave Lake from 1992 to 2008 (Figure 22). Legacy contaminants are generally declining in Great Slave Lake fish (represented by HCH levels in Figure 22), though there were no clear trends for PCB concentrations from 1992 to 2007. Changes in lake ecology and fish trophic structure in Great Slave Lake may be either accentuating or masking trends in contaminants. For example, organic contaminants accumulate more in fatty tissues and the lake trout fat levels have decreased in recent years. This reduction in fat levels may be related to changes in the relative numbers of different species in the lake or to other changes in lake ecology.Reference 123

Figure 22. Trends in mercury, PCBs and HCH in lake trout and burbot from Great Slave Lake, 1992-2008

The East Arm of Great Slave Lake is in the Taiga Shield Ecozone+. The West Basin of the lake is in the Taiga Plains Ecozone+; samples were collected in the Hay River area.

Graphs
Source: based on data from Evans, 2009Reference 123
Long description for Figure 22

These three scatter plots show the following information:

Trends in mercury, PCBs and HCH in lake trout and burbot from Great Slave Lake, 1992-2008. Hg (mercury) ng/g
YearWest Basin troutEast Arm troutWest Basin burbotEast Arm burbot
1993----
1994----
1995-117.50--
1996--82.00-
1997----
1998----
1999108.32143.44108.4883.87
2000-259.90134.82116.30
2001195.90152.84182.13122.04
2002156.60131.46157.40118.07
2003----
2004166.30152.40178.50171.40
2005179.80191.50114.60-
2006206.50160.80158.30-
2007207.00194.45240.40-
2008269.00189.09252.90189.00
Trends in mercury, PCBs and HCH in lake trout and burbot from Great Slave Lake, 1992-2008. ∑PCB (polychlorinated biphenyls) ng/g
YearWest Basin troutEast Arm troutWest Basin burbotEast Arm burbot
199313.8525.0974.52138.44
1994----
1995-20.86--
1996--96.43-
1997----
1998----
199927.5714.41118.2780.37
2000-16.68167.50127.50
200111.0125.63180.45125.90
20023.007.3683.43112.25
2003----
200417.3329.42101.06173.79
200515.2349.8671.69-
200617.3017.6464.05-
20077.4625.63--
2008----
Trends in mercury, PCBs and HCH in lake trout and burbot from Great Slave Lake, 1992-2008. ∑HCH (hexachlor°Cyclohexane) ng/g
YearWest Basin troutEast Arm troutWest Basin burbotEast Arm burbot
19932.022.626.5410.76
1994----
1995-0.96--
1996--7.07-
1997----
1998----
19993.000.755.063.04
2000-0.856.118.12
20011.641.525.847.37
20020.480.582.686.49
2003----
20040.721.181.342.61
20050.210.482.57-
20060.180.261.56-
20070.180.37--
2008----

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Burbot, which tend to accumulate organic contaminants in their large, fatty livers, have been sampled at Fort Good Hope in the Mackenzie River since the 1980s. Burbot livers are a food favoured by First Nations and Inuvialuit in the ecozone+.

Since the 1980s, mercury concentrations have almost doubled in burbot muscle (Figure 23) and have increased somewhat more in livers (not shown). There were no significant correlations between fish age or length and mercury concentrations, so the trends are not related to differences among the samples. Mean concentration over the whole time period was 343 ng/g in muscle and the maximum sample mean was 420 ng/g in 2007, approaching but not exceeding the recommended maximum for mercury in fish for commercial sale of 500 ng/g (more commonly expressed as 0.5 parts per million). Mercury levels in liver were much lower, averaging 86 ng/g. While the legacy contaminant HCH decreased over the sampling period (not shown), DDTs continued to rise, contrary to the general trend in Canada’s North. There was no clear trend for PCBs. PBDEs (brominated flame retardants) increased significantly over the 20-year period, declining in the most recent two years of sampling.

Figure 23. Contaminants in burbot, Mackenzie River at Fort Good Hope

Sample information: muscle tissue for mercury (males); liver tissue for organ°Chlorines (sexes combined, lipid weight); liver for PBDE, sexes combined, wet weight. PBDE congeners analysed for: 47, 99, 100, 153, and 154.

Graphs
Source: based on data from Stern, 2009Reference 124
Long description for Figure 23

These two line graphs show following information:

These two line graphs show following information:Contaminants in burbot, Mackenzie River at Fort Good Hope. Concentration (ng/g)
Yeartotal mercury,
burbot muscle
sum of PCBs,
burbot liver
total DDT,
burbot liver
sum of main PBDE congeners,
burbot liver
1985222---
1986----
1987----
1988-206.0557.340.40
1989----
1990----
1991----
1992----
1993231---
1994-168.861.55-
1995265---
1996----
1997----
1998----
1999286148.8553.581.48
2000345137.552.981.34
2001342138.1927.52-
2002297162.6795.621.57
2003336113.9957.272.60
2004413257.46168.22-
2005301103.4769.121.73
2006389151.22112.75.18
2007420129.2143.952.03
2008410283.38102.710.94
2009----
2010----

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A study of Mackenzie River burbot habitat in the Fort Good Hope vicinityReference 125 concluded that the increasing trends in mercury in burbot may be related to increased productivity in the aquatic environment due to climate change, with contaminants moving more readily into the food web under conditions of higher productivity. This conclusion is supported by the work of Sanei et al., 2012Reference 126 who looked at long-term trends in mercury in sediments in Mackenzie Delta lakes. Their results suggest that increasing phytoplankton productivity can lead to increases in mercury content in lake sediments – meaning that increases in mercury in biota may not be solely a result of increases in atmospheric deposition of mercury.

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Key finding 14
Climate change

Theme Human/ecosystem interactions

National key finding
Rising temperatures across Canada, along with changes in other climatic variables over the past 50 years, have had both direct and indirect impacts on biodiversity in terrestrial, freshwater, and marine systems.

Ecozone+ key finding: The Taiga Plains Ecozone+ has experienced some of the greatest increases in temperature of any Canadian region since 1950 – with the annual mean temperature increasing over 2°C and winter temperatures rising about 5°C at all stations since 1950. This warming has translated into some clear ecosystem trends, such as changes to permafrost landscapes and increases in terrestrial primary productivity. There are indications of other emerging, climate-related trends, such as the northward movement of some forest insect pests.

Trends since 1950

Annual mean temperature has increased about 1.4°C since 1950 over the country as a whole, though the amount of temperature increase differs among ecozones+.Reference 9 The strongest warming has occurred in the west and the northwest of Canada, with an increase in annual mean temperature of over 2°C for the Taiga Plains Ecozone+. When looked at by seasons, the increase occurred only in winter and spring. This warming trend has been accompanied by changes in snow and a lengthening of the growing season.

Results for the Taiga Plains Ecozone+ are summarized in Table 4. The analyses are based on 6 stations for temperature, 10 stations for precipitation, and 4 stations for snow variables. Station distribution is biased (see Figure 24), with more stations in the south; this means that ecozone+ averages should be interpreted with the understanding that they are more representative of what is occurring in the southern part of the ecozone+.

Table 4. Overview of Taiga Plains Ecozone+ climate trends, 1950-2007
Climate VariableTrends 1950-2007
Temperature
  • Significant increases in winter and spring for the ecozone+ as a whole (Figure 25). No significant trends in summer and fall overall, and at only one station in the summer.
  • Strong warming trend especially for the winter season (along with the Boreal Cordillera Ecozone+, the highest in Canada) – with an average increase of 5.2°C (Figure 24).
  • An increase in the length of the growing season by 9 days for the ecozone+ as a whole, but no significant change in the timing of the start or end of growing season.
Precipitation
  • No significant change in precipitation in any season across the ecozone+ as a whole, and few significant changes at individual stations.
Snow cover
  • A significant mean decrease of 11.4 days in snow cover duration (13% of the 1961-1990 average) in the spring half of the snow season (early melt), with no change in snow cover duration during the snow cover onset period, based on data from 4 stations.
  • A significant mean decrease in annual maximum snow depth of 23.6 cm (38% of the 1961-1990 average), based on data from 4 stations.
  • No significant trend in the fraction of annual precipitation falling as snow.

Source: Zhang et al., 2011Reference 9 and supplementary data provided by the authors

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Figure 24. Trends in seasonal temperatures at six climate stations, 1950-2007

Trends are based on temperature anomalies, measured as the difference from the base period (1961 to 1990) mean. Triangles are, coloured intense red when the trend is significant at the 5% level. Magnitude of the change (°C) is shown for all significant trends. There are no decreasing trends. Seasons are, spring: March-May; summer: June-August; fall: September-November; winter: December-February.

Maps
Source: Zhang et al., 2011Reference 9 and supplementary data provided by the authors
Long description for Figure 24

This set of four maps depicts change in mean annual temperature in each season (°C) between in cities and towns in the Taiga Plains Ecozone+, between 1950 and 2007.  Across the ecozone+, the trend is for a mean increase in temperature in all cities; there were no locations that experienced a trend towards decreasing temperature.  Winter and spring temperatures increased significantly in Normal Wells (+4.58°C; +2.12 °C), Fort Simpson (+4.50°C; +2.33 °C), Hay River (+5.17°C; +2.44 °C), Fort Nelson (+4.57°C; +2.20 °C) and Fort Smith(+5.63°C; +3.26 °C).  Inuvik also experienced an increase of 5.5°C in winter temperatures.

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Figure 25. Average winter temperature trend, 1950-2007

Temperature anomalies, measured as the difference from the base period (1961-1990) mean, are plotted. The data indicate a significant (p < 0.05) increase of 5.2°C from 1950-2007. This analysis is based on data from 6 stations (shown in Figure 24).

Graph
Source: Zhang et al., 2011Reference 9 and supplementary data provided by the authors
Long description for Figure 25

This line graph shows the following information:

Average winter temperature trend, 1950-2007.
YearMean Winter Temperature Anomaly (°C)
1950-2.51
1951-1.42
1952-2.97
19531.56
1954-0.78
19550.06
1956-2.86
1957-0.10
1958-0.68
1959-0.81
19601.84
19611.22
1962-2.25
19630.18
19641.90
1965-4.48
1966-3.79
1967-0.83
19680.33
1969-3.74
19702.30
1971-2.81
1972-3.73
19730.58
1974-1.42
1975-1.02
1976-1.67
19773.20
19781.54
1979-1.81
19803.16
19813.33
1982-2.34
1983-0.71
19840.34
1985-0.79
19863.50
19875.95
19882.70
19892.91
1990-1.76
19910.37
19921.08
19932.74
1994-1.68
19952.99
1996-0.35
19971.86
19983.02
19992.55
20003.74
20013.54
20021.75
20034.03
20041.67
20051.33
20066.21
20074.31

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Influence of climate oscillations

Large-scale oscillations of the atmospheric system in the Pacific Ocean influence the precipitation and temperature patterns of the Taiga Plains Ecozone+, especially cold-season temperatures.Reference 8 These oscillations include El Niño/Southern Oscillation (ENSO) events that occur on average every two to seven years and the Pacific Decadal Oscillation (PDO), characterized by abrupt shifts between contrasting phases every 20 to 30 years.Reference 8 The shift to positive PDO and more frequent ENSO events in the mid-1970s appears to have led to contrasting changes across the continent, resulting in greater winter and spring warming in the west than in the east, trends that are particularly strong in this ecozone+.Reference 9

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Climate trends and impacts based on local observations and Aboriginal Traditional Knowledge

In this ecozone+ and more generally in the Mackenzie Basin, documented Aboriginal Traditional Knowledge and local observations speak to a range of trends in climate and related ecological impacts. This knowledge is specific to areas and timeframes so is best interpreted within the context of the knowledge holder (see the references provided). It is beyond the scope of this report to synthesize available information. Some examples of documented observations and interpretations are presented in Table 5.

Table 5. Selected Aboriginal Traditional Knowledge related to climate change and ecosystem impacts.
Examples of observations of climate trendsExamples of observations on ecological impacts, as reported in the Mackenzie River Basin state of the aquatic ecosystem report 2003Reference 59
  • Thinner ice leads to danger to people travelling and hunting, and to migrating caribou and other wildlife.Reference 138-Reference 140
  • Water levels have decreased over a period of one to two decades and small lakes and streams have disappearedReference 139-Reference 142 leading to reduced habitat for fish, waterfowl, and muskrat, which have declined in some areas,Reference 141 interfering with fishing, because traditional fishing sites are too shallow to set netsReference 143 and interfering with travel when important boating routes become too shallow to navigate.Reference 141
  • Changes in vegetation and less berry production; increases in forest fires resulting in loss of wildlife habitat and loss of trapping areas; new species appearing (such as cougars) that were never in the area before.Reference 138, Reference 139, Reference 142

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Climate change impacts

Changes in indicators such as air temperature and permafrost are well documented for the Taiga Plains and show clear trends consistent with climate change. Effects on ecosystems are not as apparent, partly because they are not as well documented.Reference 19 There are indications of ecosystem trends that are primarily climate related, discussed under many of the key findings in this report. Examples:

  • Vegetation community changes in the treeline zone and altered growth rates of white spruce (Forests key finding).
  • Increases in terrestrial primary productivity especially in the north of the Taiga Plains (Primary productivity key finding).
  • Early indications of a trend to reduced frequency of periodic spring flooding in delta wetlands and lakes (Wetlands key finding).
  • Widespread trend to increased streamflow in winter. Some indications of earlier peak flows (upstream in the Mackenzie River Basin) and of increased streamflow variability (Lakes and rivers key finding).
  • Loss of frozen peatlands (Ice across biomes key finding) and increased slumping from thawing ground ice in delta lakes, affecting water quality (Wetlands key finding).
  • Northward spread of some forest insect pests, likely related to warmer temperatures (Natural disturbances key finding).

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Key finding 15
Ecosystem services

Theme Human/ecosystem interactions

National key finding
Canada is well endowed with a natural environment that provides ecosystem services upon which our quality of life depends. In some areas where stressors have impaired ecosystem function, the cost of maintaining ecosystem services is high and deterioration in quantity, quality, and access to ecosystem services is evident.

Ecozone+ key finding: Provisioning services of the ecozone+ include harvest of fish, wildlife, and plants, of cultural, spiritual, nutritional, and economic importance. Reliance on these provisioning services is high and not declining, especially in rural communities. Quality of these services generally remains high, with the exception of declines in barren-ground caribou, leading to harvest restrictions and reduced harvest success in some communities.

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Putting a value to ecosystem services: the boreal forest

Typically, ecosystem goods and services are described through economic analyses to estimate the value of natural capital. However, there are clearly other goods and services that cannot be expressed in economic terms. For example, the Taiga Plains Ecozone+ provides services as a migratory corridor and as the breeding grounds for many boreal forest birds. Cultural services are particularly difficult to assign value to.

The Pembina Institute identified and valued the natural capital of Canada’s boreal forests, including in the analysis the value of forests, agriculture, mineral and energy resources, fish and wildlife, wetlands, peatlands, lakes, and rivers.Reference 144 The analyses focused on ecosystem services such as atmospheric stabilization; climate stabilization; disturbance avoidance; water stabilization; water supply; erosion control and sediment retention; soil formation; nutrient cycling; waste treatment; pollination; biological control such as bird predation of insect pests; habitat; raw materials; genetic resources; and recreation and cultural use. The value of the boreal forest’s ecosystem services ($93.2 billion) is at least 2.5 times greater than the market values of forestry, mining, oil and gas, and hydroelectricity combined ($37.8 billion). The market values do not include either societal or environmental costs separately valued at $11.1 billion. This analysis was not undertaken at the ecozone+ scale.

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Provisioning services

Harvest of fish, wildlife, and plants

Harvesting fish, birds, mammals, and plant species in the Taiga Plains has long supported the needs and culture of aboriginal people. Across the NWT, about 37 to 45% of NWT residents went hunting or fishing in 2002, a statistic that has changed little since the first survey in 1983.Reference 145 The number of aboriginal subsistence hunters in the Taiga Plains is about 5,800; there are no trend data for hunting activity for this group of residents. The number of resident hunters (non-aboriginal hunters) declined by about 3% per year from 1990 to 2004 and stabilized at about 1,200-1,300 hunters annually in recent years.Reference 145

Since hunting and fishing are a way of life for many Taiga Plains residents, earlier river ice break-upReference 131 is a concern. Freeze-up timing tends to be less predictable now than it was in the pastReference 137 and the ice is thinner. Changes in freeze-up patterns are raising concerns about hunter and fisher safety, especially in Gwich’in and Inuvialuit communities, where frozen lakes and rivers provide transportation routes and are used for much of the year for traditional activities such as ice fishing.Reference 131

Between 20 and 30% of households in the NWT portion of the Taiga Plains rely heavily on the provisioning services provided by local fish and game (Figure 26). The percentage would be considerably higher for Taiga Plains households outside of Inuvik, as, for all of the NWT, about 50% of households in small communities reported obtaining most or all meat and fish from local harvest in 2009, in contrast with 16% of households in medium sized communities, which includes Inuvik.Reference 145

Figure 26. Percent of households in the Taiga Plains and Taiga Cordillera (NWT) reporting that most or all of their meat and fish was harvested from the NWT, 1994-2009

Note that this primarily represents households in the Taiga Plains, as there is only one small community (Wrigley) in the NWT part of the Taiga Cordillera Ecozone+.

Graph
Source: data from Environment and Natural Resources, 2011Reference 145
Long description for Figure 26

This bar graph shows the following information:

Percent of households in the Taiga Plains and Taiga Cordillera (NWT) reporting that all or most of their meat and fish was harvested from the NWT, 1994-2009.
YearPercent of households
199421.5
199927.5
200424
200922.5

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Mammals

Mammal species harvested in the middle to northern part of the ecozone+ are shown in Figure 27. The three land claims settlement areas for which data are shown do not fully coincide with the ecozone+ (for example, the small muskox harvest would be mainly outside of the ecozone+), but the data provide a good indication of mammal species important to humans through much of the ecozone+. The mammal harvest is a mix of harvest for meat and for fur. The dominant mammal harvested for meat is the barren-ground caribou.

There is limited information on trends in caribou harvest – some is available through harvest studies established under land claims legislation.Reference 146 Information on the western Northwest Territories herds (Cape Bathurst, Bluenose-West, and Bluenose-East) is available through the Gwich’in Harvest StudyReference 147 and Inuvialuit Harvest StudyReference 148 for community caribou harvests from 1988 to 1997. Information for 1998 to 2005 is available through the Sahtu Harvest Study.Reference 149, Reference 150 As an example of harvest trends drawn from these studies, harvest from the Bluenose-West Herd in the Sahtu decreased from 1,022 in 1999 to 270 caribou in 2005.Reference 151 The Bluenose-West Herd is subject to harvest restrictions due to a decrease in population (see the section on caribou in the key finding on Species of special interest, on page 59).

Figure 27. Summary of annual harvest levels of major mammal species in the Gwich’in and Sahtu settlement areas and the Inuvialuit Settlement Region

Note: four of the six communities included in the Inuvialuit Settlement Region lie outside the Taiga Plains Ecozone+

Graph
Source: Joint Secretariat, 2003 as presented in SENES Consultants Ltd., 2005Reference 152
Long description for Figure 27

This bar graph shows the number of animals harvested annually in the Gwich’in and Sahtu settlement areas and Inuvialuit settlement area (ISR), divided into panels displaying data for large and small mammals.  Barren ground caribou was the most harvested large mammal in all three areas, with harvest numbers in the thousands.  Moose were harvested at low numbers in all three areas, but by far the most in the Sahtu area at around 200 animals.  Muskox was only harvested in the ISR, and woodland caribou only in the Sahtu area.  In the ISR, muskrat was harvested in large numbers (10,000), with fox and hare species also being important.  In the Gwich’in area, muskrat were harvested at a moderate level (>2000), with hare species and marten being the next most abundant harvests.  Hare species were the most harvested animal in the Sahtu area, followed by marten and smaller numbers of muskrat and beaver.

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Waterfowl

The numbers of waterfowl harvested for sport and subsistence in the NWT are relatively low, but ducks and geese are important in the traditional diet.Reference 152 In the Gwich’in region, the top three waterfowl species for subsistence harvest are scoters, mallard, and snow geese.Reference 147

Fish

Fisheries in the Taiga Plains include household, commercial, and recreational, both in rivers and lakes. Some examples of locally important fisheries in the ecozone+:

  • Eleven species of fish are caught using nets in the household fishery in the Gwich’in Settlement Area in the north of the ecozone+, the most important being inconnu (locally called coney, Stenodus leucichthys), Dolly Varden char (Salvelinus malma malma), burbot (locally called loche, Lota lota), and lake whitefish (locally called crookedback, Coregonus autumnali).Reference 19
  • There are both commercial and sport fisheries for lake trout, pike, and inconnu in Great Slave Lake, managed through a mix of area closures, catch limits and gear restrictions.Reference 19
  • Great Bear Lake, as well as being a source of fish for household fisheries, supports a lodge-based sport fishery for lake trout.Reference 153
Berries and products of the boreal forest

Non-timber forest products such as mushrooms, berries, birch sap syrup, floral greens, medicinal herbs, and forest crafts have a long history of traditional use and trade in the Taiga Plains.Reference 145 Participation rates in plant and berry gathering activities during 2002 in the NWT portion of the Taiga Plains are shown in Figure 28.

Figure 28. Percentage of population 15 years of age and older involved in harvesting berries and plants in 2002, north and south Taiga Plains, NWT
Graph
Source: NWT Bureau of Statistics, 2002Reference 154
Long description for Figure 28

This bar graph shows the following information:

Percentage of population 15 years of age and older involved in harvesting berries and plants in 2002, north and south Taiga Plains, NWT.
-Gathered berriesGathered plants
Taiga Plains North1910
Taiga Plains South2711

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However, when looked at on a household basis, and for communities in the Gwich’in Settlement Area, the use of berries is much higher – with almost all households collecting berries and 82% of households collecting Labrador tea leaves, based on a random survey of Gwich’in households in 2000 (Figure 29). The plant names in Figure 29 are the commonly used English names in the region; Latin and Gwich’in names, respectively, are: cranberry: Vaccinium vitis-idaea, natå'at; blueberry: Vaccinium uliginosum, jàk zheii; yellowberry (cloudberry): Rubus chamaemorus, nakàl; Labrador tea: Ledum palustre and groenlandicum, lidii maskeg/maskig.

Figure 29. Use of berries and Labrador tea by Gwich’in households, Fort McPherson, Inuvik, Aklavik, and Tsiigehtchic, 2000

The bars show the estimated average volume of berries and Labrador tea leaves collected per household, averaged over the four communities. The percentage on top of each bar is the estimated percentage of households across the communities active in collecting the particular plant product during the year 2000.

Graph
Source: data from Government of the Northwest Territories, 2009Reference 155
Long description for Figure 29

The bar graph presents the following information:

Use of berries and Labrador tea by Gwich’in households, Fort MacPherson, Inuvik, Aklavik and Tsiigehtchic, 2000.
-Litres per household% of households
Cranberry4396
Blueberry2895
Yellowberry5599
Labrador tea leaves3782

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Trapping

Wild fur from the NWT is considered among the very best in the world and has a long history. In the 1960s and 1970s several species contributed about equally to the total annual fur harvested in the NWT (marten, lynx, muskrat and beaver). However, marten has accounted for most of the NWT fur value during the past 20 years. Marten are a good indicator for trapping because they are widely distributed, relatively easy to trap, and their consistently high pelt value is an incentive for trappers to target this species. Furbearer abundance and availability, fashion trends, international market demand for fur, and the amount of trapping effort all influence trends in fur sales.Reference 145 The number of people trapping in the NWT has decreased since the early 1980s, but leveled to more stable numbers in recent years.Reference 145 Trapping remains an activity of cultural importance and provides ongoing supplementary income to approximately 500 people in the NWT portion of the Taiga Plains (Figure 30).

Figure 30. Trends in numbers of trappers in NWT Taiga Plains communities compared with other NWT ecozones

Note that the two upper lines represent trapping in the Taiga Plains.

Graph
Source: Environment and Natural Resources, 2011;Reference 145 data from the GNWT Fur Harvest Database, GNWT Department of Industry, Tourism and Investment
Long description for Figure 30

This line graph illustrates that between 2001 and 2008, the number of trappers in the north and south Taiga Plains was much higher than in other NWT ecozones+.  The northern and southern Arctic and Taiga Cordillera ecozones+ have few (< 50) trappers and the Taiga Shield has slightly fewer than the north Taiga Plains, with approximately 150 trappers.   In comparison, the northern Taiga Plains typically had around 200 trappers in this time period, and in the southern Taiga Plains the number of trappers ranged from 350 to 250.

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Commercial timber harvest

The commercial timber harvesting in the NWT portion of the Taiga Plains is a minor industry. The volume of timber cut down during seismic exploration projects is estimated to be at least an order of magnitude greater than the volume cut by commercial timber harvest operations.Reference 145 In the NWT, wood is harvested for saw logs and firewood. Typical commercial harvest operations are small-scale local businesses harvesting from 500 to 10,000 m3 per year. The trend in timber harvesting (across the territory) showed an increase during the 1990s, then decreased in the early 2000s before increasing slightly.Reference 145

By contrast, commercial timber harvest has been an important influence in the southwestern part of the ecozone+. Forest products were significant to the economy of the Fort Nelson region until the recent decrease in demand for building materials in the U.S. led to the closure of the Tackama Mill in Fort Nelson. The Fort Nelson mill was, in the mid-2000s, BC’s largest plywood facility.Reference 156

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