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Restoring the Great Lakes Areas of Concern

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The Great Lakes basin is Canada's most populated region. Its large population and extensive development places a strain on ecosystem health. Locations having experienced a high level of environmental damage from human activity are called Areas of Concern. This indicator assesses progress on restoring Areas of Concern around the Great Lakes within Canadian waters and those shared with the United States.

Key results

Key results

  • Environmental quality in Canada's 17 Great Lakes Areas of Concern has improved since the restoration program began in 1987
  • As of 2023, 3 of the 17 Areas of Concern have been fully restored and delisted

Status of Canada's 17 Great Lakes Areas of Concern, 2023

Map of the 17 areas of concern
Data table for the long description
Status of Canada's 17 Great Lakes Areas of Concern, 2023
Lake Area of Concern Assessment year Status as of March 31, 2023
Superior Thunder Bay 1991, 2012 Area of Concern
Superior Nipigon Bay 1991 Area of Concern
Superior Jackfish Bay 1991 Area of Concern in Recovery
Superior Peninsula Harbour 1991, 2012 Area of Concern
n/a St. Marys River 1992 Area of Concern
Huron Spanish Harbour 1993 Area of Concern in Recovery
Huron Severn Sound 1988 Restored Area of Concern
Huron Collingwood Harbour 1989 Restored Area of Concern
n/a St. Clair River 1991 Area of Concern
n/a Detroit River 1991, 1998 Area of Concern
Erie Wheatley Harbour 1998 Restored Area of Concern
n/a Niagara River 1993 Area of Concern
Ontario Hamilton Harbour 1992 Area of Concern
Ontario Toronto and Region 1989 Area of Concern
Ontario Port Hope Harbour 2003 Area of Concern
Ontario Bay of Quinte 1990 Area of Concern
Ontario St. Lawrence 1992 Area of Concern

Note: n/a = not applicable, Great Lake tributary river. Assessment reports were published between 1988 and 1993, in what were titled Stage 1 Remedial Action Plan reports, with the exception of Wheatley Harbour and Port Hope Harbour, which were produced in 1998 and 2003, respectively. Many of these included undefined status for certain beneficial uses, and they “required further assessment”. Upon further assessment over subsequence years, what had been undefined was clarified in Remedial Action Plan status update reports. In these cases, a second year is noted as assessment year.
Source: Environment and Climate Change Canada (2023) Great Lakes Areas of Concern Office.

Download data file (Excel/CSV; 1.7 kB)

How this indicator was calculated

Note: As of 2016, the Nipigon Bay Area of Concern had all of its impaired beneficial uses restored; however, it cannot be formally designated as a Restored Area of Concern until the final approval of its completion report following public consultations on its delisting. Area of Concern status is based on progress reported as of March 31, 2023.

Source: Environment and Climate Change Canada (2023) Great Lakes Areas of Concern Office.

In 1987, the Canada-United States Great Lakes Water Quality Agreement identified 43 Areas of Concern around the Great Lakes. Of these Areas of Concern:

  • 26 were entirely in American waters
    o    6 of which have been restored: Oswego River (2006), Presque Isle Bay (2013), Deer Lake (2014), White Lake (2014), Lower Menominee River (2020) and Ashtabula River (2021)
  • 5 were shared between Canada and the United States
  • 12 were entirely in Canadian waters

To date, considerable progress has been made towards the restoration of Canada's 17 Areas of Concern (including the 5 shared with the United States):

  • 3 have been fully restored and delisted: Collingwood Harbour (1994), Severn Sound (2002) and Wheatley Harbour (2010)
  • 1 more has had all impaired beneficial uses restored and community engagement will continue until it is removed from the list of Areas of Concern: Nipigon Bay (2016)
  • 2 have been formally designated as Areas of Concern in Recovery, signifying that all remedial actions have been completed and the natural recovery of the ecosystem will continue to be monitored: Spanish Harbour (1999) and Jackfish Bay (2011)
  • Efforts continue to restore the remaining 11 Areas of Concern: Peninsula Harbour, Thunder Bay, Bay of Quinte, Port Hope Harbour, Toronto and Region, Hamilton Harbour, St Lawrence River, St. Clair River, St. Marys River, Niagara River and Detroit River

Progress on restoring the Great Lakes Areas of Concern

Key results

  • As of March 2023, 72 of the 121 impaired beneficial uses identified in Canada's 17 Areas of Concern have been restored. Efforts continue to restore the 49 remaining impaired beneficial uses
  • Between April 2021 and March 2023, 4 beneficial uses were restored (out of the 72 restored in total) in the Thunder Bay, Peninsula Harbour, Niagara River and Bay of Quinte Areas of Concern

Progress on Canada's 17 Great Lakes Areas of Concern, 1987 to 2023

Progress on Canada's 17 Great Lakes Areas of Concern, 1987 to 2023 (see data table for long description)
Data table for the long description
Progress on Canada's 17 Great Lakes Areas of Concern, 1987 to 2023
Lake Area of Concern Initial assessment
(number of beneficial use impaired)		 2023 assessment year: total impaired
(number of beneficial use impaired by category of impact)		 2023 impaired beneficial use 2023 assessment year: total restored
(number of beneficial use restored by category of impact)		 2023 restored beneficial use Year and number of restored beneficial use Beneficial use not impaired
Superior Thunder Bay 7 Environment: 3
  • Degradation of fish and wildlife populations
  • Degradation of benthos
  • Loss of fish and wildlife habitat
 Economy: 3
Human heath: 1
  • Restrictions on dredging activities
  • Degradation of aesthetics
  • Added costs to agriculture or industry
  • Beach closings
 2004: 1
2012: 1
2019: 1
2023: 1		 7
Superior Nipigon Bay [A] 7 No impaired beneficial use n/a Environment: 4
Economy: 3
  • Degradation of fish and wildlife populations
  • Degradation of benthos
  • Eutrophication or undesirable algae
  • Loss of fish and wildlife habitat
  • Tainting of fish and wildlife flavor
  • Restrictions on dredging activities
    Degradation of aesthetics
 1995: 2
2016: 5		 7
Superior Jackfish Bay [B] 5 Environment: 3
  • Degradation of fish and wildlife populations
  • Degradation of benthos
  • Loss of fish and wildlife habitat
 Environment: 1
Economy: 1
  • Fish tumours or other deformities
  • Restrictions on dredging activities
 1998: 1
2010: 1		 9
Superior Peninsula Harbour 3 Human heath: 1 Restrictions on fish and wildlife consumption Economy: 1
Environment: 1
  • Restrictions on dredging activities
  • Degradation of benthos
 2012: 1
2022: 1		 11
n/a[D] St. Marys River 9 Environment: 4
Human heath: 1
Economy: 1
  • Degradation of fish and wildlife populations
  • Fish tumours or other deformities
  • Degradation of benthos
    Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
  • Restrictions on dredging activities
 Environment: 1
Human heath: 1
Economy: 1
  • Eutrophication or undesirable algae
  • Beach closing
    Degradation of aesthetics
 2018: 3 5
Huron Spanish Harbour [B] 6 Environment: 1
Human heath: 1
  • Degradation of benthos
  • Restrictions on fish and wildlife consumption
 Environment: 1
Human heath: 1
Economy: 2
  • Degradation of fish and wildlife populations
    Beach closing
  • Restrictions on dredging activities
  • Added costs to agriculture or industry
 1999: 3
2020: 1		 8
Huron Severn Sound [C] 5 No impaired beneficial use n/a Environment: 3
Human heath: 1
Economy: 1
  • Degradation of fish and wildlife populations
  • Eutrophication or undesirable algae
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
  • Restrictions on dredging activities
 2002: 5 9
Huron Collingwood Harbour [C] 9 No impaired beneficial use n/a Environment: 5
Human heath: 2
Economy: 2
  • Degradation of fish and wildlife populations
  • Bird or animal deformities or reproduction problem
  • Degradation of benthos
    Eutrophication or undesirable algae
  • Degradation of phytoplankton and zooplankton populations
  • Restrictions on fish and wildlife consumption
  • Degradation of aesthetics
    Beach closing
    Restrictions on dredging activities
 1994: 9 5
n/a[D] St. Clair River 8 Environment: 2
Human heath: 2
  • Degradation of benthos
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
  • Restrictions on drinking water consumption, or taste and odour problems
 Human heath: 1
Economy: 3
  • Beach closing
  • Restrictions on dredging activities
  • Degradation of aesthetics
    Added costs to agriculture or industry
 2012: 1
2016: 1
2018: 2		 6
n/a[D] Detroit River 12 Environment: 3
Human heath: 1
  • Degradation of fish and wildlife populations
  • Bird or animal deformities or reproduction problems
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
 Environment: 2
Human heath: 2
Economy: 4
  • Fish tumours or other deformities
  • Degradation of benthos
  • Restrictions on drinking water consumption, or taste and odour problems
  • Beach closing
    Tainting of fish and wildlife flavor
  • Restrictions on dredging activities
  • Degradation of aesthetics
  • Added costs to agriculture or industry
 2010: 2
2014: 1
2016: 2
2019: 1
2020: 2		 2
Huron Severn Sound [C] 5 No impaired beneficial use n/a Environment: 3
Human heath: 1
Economy: 1
  • Degradation of fish and wildlife populations
  • Eutrophication or undesirable algae
  • Loss of fish and wildlife habitat
    Restrictions on fish and wildlife consumption
  • Restrictions on dredging activities
 2002: 5 9
Huron Collingwood Harbour [C] 9 No impaired beneficial use n/a Environment: 5
Human heath: 2
Economy: 2
  • Degradation of fish and wildlife populations
  • Bird or animal deformities or reproduction problem
  • Degradation of benthos
  • Eutrophication or undesirable algae
  • Degradation of phytoplankton and zooplankton populations
  • Restrictions on fish and wildlife consumption
  • Degradation of aesthetics
  • Beach closing
  • Restrictions on dredging activities
 1994: 9 5
n/a[D] St. Clair River 8 Environment: 2
Human heath: 2
  • Degradation of benthos
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
  • Restrictions on drinking water consumption, or taste and odour problems
 Human heath: 1
Economy: 3
  • Beach closing
  • Restrictions on dredging activities
  • Degradation of aesthetics
  • Added costs to agriculture or industry
 2012: 1
2016: 1
2018: 2		 6
n/a[D] Detroit River 12 Environment: 3
Human heath: 1
  • Degradation of fish and wildlife populations
  • Bird or animal deformities or reproduction problems
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
 Environment: 2
Human heath: 2
Economy: 4
  • Fish tumours or other deformities
  • Degradation of benthos
  • Restrictions on drinking water consumption, or taste and odour problems
  • Beach closing
  • Tainting of fish and wildlife flavor
  • Restrictions on dredging activities
  • Degradation of aesthetics
  • Added costs to agriculture or industry
 2010: 2
2014: 1
2016: 2
2019: 1
2020: 2		 2
Erie Wheatley Harbour [C] 5 No impaired beneficial use n/a Environment: 3
Human heath: 1
Economy: 1
  • Degradation of fish and wildlife populations
  • Eutrophication or undesirable algae
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
  • Restrictions on dredging activities
 2010: 5 9
n/a[D] Niagara River 8 Environment: 3
Human heath: 1
  • Degradation of fish and wildlife populations
  • Degradation of benthos
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
 Environment: 2
Economy: 1
Human heath: 1
  • Bird or animal deformities or reproduction problems
  • Eutrophication or undesirable algae
  • Restrictions on dredging activities
  • Beach closing
 2009: 2
2019: 1
2023: 1		 6
Ontario Hamilton Harbour 8 Environment: 4
Human heath: 2
Economy: 2
  • Degradation of fish and wildlife populations
  • Degradation of benthos
  • Eutrophication or undesirable algae
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
  • Beach closing
  • Restrictions on dredging activities
  • Degradation of aesthetics
 No restored beneficial use n/a No restored beneficial use 6
Ontario Toronto and Region 8 Environment: 3
Human heath: 2
  • Degradation of fish and wildlife populations
  • Eutrophication or undesirable algae
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
  • Beach closing
 Environment: 1
Economy: 2
  • Degradation of benthos
  • Restrictions on dredging activities
  • Degradation of aesthetics
 2016: 2
2020: 1		 6
Ontario Port Hope Harbour 1 Economy: 1 Restrictions on dredging activities No restored beneficial use n/a No restored beneficial use 13
Ontario Bay of Quinte 10 Environment: 2
Human heath: 1
  • Eutrophication or undesirable algae
  • Degradation of phytoplankton and zooplankton populations
  • Restrictions on fish and wildlife consumption
 Environment: 3
Human heath: 2
Economy: 2
  • Degradation of fish and wildlife populations
  • Loss of fish and wildlife habitat
  • Degradation of benthos
  • Restrictions on drinking water consumption, or taste and odour problems
  • Beach closing
  • Restrictions on dredging activities
  • Degradation of aesthetics
 2017: 1
2018: 3
2019: 1
2020: 1
2022: 1		 4
Ontario St. Lawrence 10 Environment: 3
Human heath: 2
  • Degradation of fish and wildlife populations
  • Eutrophication or undesirable algae
  • Loss of fish and wildlife habitat
  • Restrictions on fish and wildlife consumption
  • Beach closing
 Environment: 1
Human heath: 1
Economy: 3
  • Degradation of benthos
  • Restrictions on drinking water consumption, or taste and odour problems
  • Restrictions on dredging activities
  • Degradation of aesthetics
  • Added costs to agriculture or industry
 1997: 3
2007: 2		 4
Total n/a 121 49 n/a 72 n/a 72 117

Note: n/a = not applicable. The number of beneficial uses that are Impaired for 2023 is based on progress reported as of March 31, 2023. [A] All impaired beneficial uses have been restored in the Area of Concern; however, it cannot be formally designated as a Restored Area of Concern until the final approval of the completion report. [B] Area of Concern in Recovery. [C] Restored Area of Concern. [D] Great Lake tributary river.
Source: Environment and Climate Change Canada (2021) Great Lakes Areas of Concern Office

Download data file (Excel/CSV; 7.6 kB)

How this indicator was calculated

Note: [A] As of 2016, the Nipigon Bay Area of Concern had all of its impaired beneficial uses restored; however, it cannot be formally designated as a Restored Area of Concern until the final approval of its completion report following public consultations on its delisting. The number of beneficial uses that are Impaired in 2023 is based on progress reported as of March 31, 2023.
Source: Environment and Climate Change Canada (2023) Great Lakes Areas of Concern Office.

At the 17 Areas of Concern, 121 beneficial uses have been considered impaired since the restoration program began in 1987. Beneficial uses describe how an aquatic ecosystem benefits the environment, economy or human health: they are the ecological services that are available to the population and the environment when the ecosystem is healthy (in other words, not impaired).

An impaired beneficial use has experienced enough changes to the chemical, physical or biological integrity of the area to restrict human use or to restrict the area's ability to support plants and animals. Before classifying an area as an Area of Concern, 14 beneficial uses are considered. Each of the 14 beneficial uses can be classified based on their impairment under 1 of the following Categories of impact:Footnote 1

Environment (7)

  1. Degradation of fish and wildlife populations
  2. Fish tumours or other deformities
  3. Bird or animal deformities or reproduction problems
  4. Degradation of benthos
  5. Degradation of phytoplankton and zooplankton populations
  6. Eutrophication or undesirable algae
  7. Loss of fish and wildlife habitat

Economy (4)

  1. Tainting of fish and wildlife flavour
  2. Restrictions on dredging activities
  3. Degradation of aesthetics
  4. Added costs to agriculture or industry

Human health (3)

  1. Restrictions on fish and wildlife consumption
  2. Restrictions on drinking water consumption, or taste and odour problems
  3. Beach closing
About the indicator

About the indicator

What the indicator measures

This indicator assesses progress towards the restoration of Canada's 12 Areas of Concern and the 5 Areas of Concern shared with the United States.

An Area of Concern is a region in the Great Lakes that has experienced a high level of environmental damage from human activity. There are 14 beneficial uses that are considered in order to decide whether an area should be classified as an Area of Concern. Beneficial uses describe how an aquatic ecosystem benefits the economy, human health and the environment: they are the ecological services that are available to the population and the environment when the ecosystem is healthy (not impaired). An Impaired beneficial use has experienced enough changes to the chemical, physical or biological integrity of the area to restrict human use or to restrict the area's ability to support plants and animals.

The status of a beneficial use is determined by monitoring and conducting scientific studies in the Area of Concern. The study results are compared to the findings for reference sites and targets listed in the site's remedial action plan and other update reports.

Why this indicator is important

This indicator is used to provide information about the state of the Great Lakes and the Canadian environment. It tracks the work done to repair the environment at 17 Areas of Concern in Canada. In these areas, the degraded environment has disrupted fisheries, wildlife, tourism, recreation and/or agriculture.

Related initiatives

The indicator contributes to the Sustainable Development Goals of the 2030 Agenda for Sustainable Development. It is linked to the 2030 Agenda's Goal 6: Clean water and sanitation.

The indicator also assesses progress towards the goals of the Canada-Ontario Agreement on Great Lakes Water Quality and Ecosystem Health, 2021. Specifically, it measures progress towards restoring the remaining impaired beneficial uses in the Canadian Great Lakes Areas of Concern (Thunder Bay,  Jackfish Bay, Peninsula Harbour, St. Marys River, Spanish River, St. Clair River, Detroit River, Niagara River, Bay of Quinte, St. Lawrence River, Hamilton Harbour, Toronto and Region, and Port Hope Harbour).

Related indicators

The Phosphorus levels in the offshore waters of the Great Lakes indicator reports total phosphorus levels in the offshore waters of the 4 Canadian Great Lakes.

The Water quality in Canadian rivers indicators provide a measure of the ability of river water across Canada to support plants and animals.

Data sources and methods

Data sources and methods

Data sources

Environment and Climate Change Canada's Great Lakes Areas of Concern program tracks the status of all beneficial uses in Canada's 17 Areas of Concern (including the 5 shared with the United States). This information is developed as Canada exercises its responsibility under the Canada-United States Great Lakes Water Quality Agreement to remove a beneficial use impairment designation when the established criteria have been met. The most recent data available for each Area of Concern are used to calculate this indicator.

More information

The 2023 data were obtained from Environment and Climate Change Canada's Areas of Concern Office. Progress reports summarizing the status of all beneficial uses for all Canadian Areas of Concern have been compiled every 1 to 3 years since 2012. Prior to 2012, beneficial use classifications were taken from remedial action plans and update reports.

Data coverage for this indicator begins with Severn Sound's Stage 1 report published in 1988 and includes data up to March 31, 2023. The other Areas of Concern released their Stage 1 reports between 1989 and 1993, with the majority being released in 1991. Wheatley Harbour released a combined Stage 1 and 2 report in 1998.

The Port Hope Harbour Area of Concern is being restored through the Port Hope Area Initiative, launched in 2001. Canadian Nuclear Laboratories is implementing the Port Hope Project on behalf of Atomic Energy of Canada Limited, a federal Crown corporation because of the nature and scope of the contamination at this site. Only the progress reports compiled since 2003 were considered for Port Hope Harbour.

Description of the Areas of Concern process

The 1987 revision of the Canada-United States Great Lakes Water Quality Agreement identified 43 Areas of Concern in Canadian and American waters of the Great Lakes. All Canadian Areas of Concern, have a remedial action plan to guide restoration and protection efforts targeting specific beneficial uses.Footnote 2 

In the former process, under the 1987 Protocol to the Canada-United States Great Lakes Water Quality Agreement, remedial action plans were developed and implemented in 3 stages.

  • Stage 1 identified which of 14 beneficial uses were classified as Impaired or Not impaired, as well as the sources and causes of the problem
  • Stage 2 established the goals, objectives and actions required to restore the ecosystem to a healthy state
  • Stage 3 documented the successful restoration of the Area of Concern as measured against the objectives (delisting criteria) outlined in the Stage 2 Remedial Action Plan report

When the beneficial uses were considered Not Impaired, and Stage 3 was complete, the Area of Concern was declared Restored and officially “delisted”. Typically, Canada waited to change the status of beneficial uses to Not Impaired in bunches (for example, with the release of a stage update report) or en masse (for example, with the completion of Stage 3).

Under the 2012 Canada-United States Great Lakes Water Quality Agreement, the process was modified and remedial action plans are now periodically updated to reflect restoration progress. That is, the Parties will not wait to change the status of beneficial uses en masse. Canada:

  • will remove an Impaired beneficial use designation when established criteria have been met
  • may elect to identify an Area of Concern as an Area of Concern in Recovery when all actions identified in a remedial action plan have been implemented and monitoring shows recovery is progressing as anticipated
  • will remove the Area of Concern or Area of Concern in Recovery designation when environmental monitoring confirms
  • beneficial use restoration criteria have been met

An Area of Concern in Recovery is an area originally identified as an Area of Concern where, on the basis of community and government consensus, all scientifically-feasible and economically-reasonable actions have been implemented and additional time is required for the environment to recover.

The reports prepared for each Area of Concern and additional information can be found at Great Lakes: Areas of Concern.

Methods

The number of beneficial uses listed as Impaired was counted for all Stage 1 reports and all update reports conducted up to the end of March 2023. The results include the beneficial uses for Canada's 12 Areas of Concern, covering the 4 Canadian Great Lakes, as well as the 5 Areas of Concern shared with the United States in their connecting channels.

An Impaired beneficial use can be classified as Restored if all delisting requirements for that beneficial use impairment have been met. Criteria for a beneficial use impairment are established in consideration of conditions that can be eventually achieved on a lake-wide basis.

Caveats and limitations

This indicator does not show the continuous nature of the rehabilitation process for each Area of Concern because the status for each beneficial use impairment can only change when new reports are published and the party (Canada) has confirmed the status as per the provisions in Annex 1 of the Great Lakes Water Quality Agreement. With progress reports being updated annually, the staggered change is less evident.

Port Hope Harbour follows a separate program, the Port Hope Area Initiative that is being implemented by Canadian Nuclear Laboratories on behalf of Atomic Energy of Canada Limited.

Resources

Resources

References

Environment and Climate Change Canada (2013) 2012 Great Lakes Water Quality Agreement: annex 1. Retrieved on March 22, 2023.

Related information

Great Lakes: Areas of Concern

Canada-United States Great Lakes water quality agreement, 2012

Canada-Ontario Agreement on Great Lakes Water Quality and Ecosystem Health, 2021

2022 Progress Report of the Parties

Infographic
 
Long description

The infographic presents information on the indicator Restoring the Great Lakes Areas of Concern. The first image shows the location and status of Canada's 17 Great Lakes Areas of Concern on a map. Four (4) Areas of Concern are located on Lake Superior, 3 on Lake Huron, 1 on Lake Erie and 4 on Lake Ontario. The remaining 5 are located on the channels connecting the lakes and are shared by Canada and the United States. An Area of Concern is a region in the Great Lakes that shows a high level of environmental damage from human activity. As of 2023, 3 Areas of Concern have had all impaired beneficial uses restored: Severn Sound and Collingwood Harbour on Lake Huron and Wheatley Harbour on Lake Erie. There are 2 Areas of Concern in Recovery: Spanish Harbour on Lake Huron and Jackfish Bay on Lake Superior. The second image presents the 72 restored beneficial uses in 3 categories of impact: 28 Environment, 30 Economy and 14 Human health. Since 1987, 72 out of 121 impaired  beneficial uses have been restored. 

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