Introduction

The Great Lakes are a precious globally significant ecosystem that hold 20% of Earth’s surface freshwater, which sustain our human health, environment and economy.

The purpose of the Canada-Ontario Agreement on Great Lakes Water Quality and Ecosystem Health (COA) is to restore, protect and conserve Great Lakes water quality and ecosystem health. Canada and Ontario signed the first COA in 1971 and have signed 8 subsequent agreements, leading to over a half-century of progress and continuous cooperation on water quality and ecosystem health. COA commitments and results directly support commitments in the Canada-U.S. Great Lakes Water Quality Agreement (GLWQA) and commitments under Ontario’s Great Lakes Strategy.

The ninth and most recent COA came into effect on June 1, 2021, and remains in force until May 31, 2026. This progress report describes notable accomplishments for each Annex to the COA from June 2021 to December 2023. A final report on progress will be issued after the 2021 COA expires. Progress is also reported by Canada through the GLWQA, and by Ontario under the Great Lakes Protection Act, 2015.

Progress under the 2021 COA is achieved in collaboration with many partners including First Nations, Métis, municipalities, academia, nongovernmental organizations and others. In 2023, the Government of Canada made a historic investment of $420 million over 10 years in new resources for the Great Lakes. This funding, in combination with Ontario’s $14 million annual investment in Great Lakes protection and additional $31 million investment for wetland protection, will contribute to the achievement of ambitious environmental results, including the clean up of Areas of Concern and meeting phosphorus load reduction targets established for Lake Erie.

Read the COA and learn more about its priorities and Annexes.

Priority: Protecting waters

Annex 1: Nutrients

Purpose: Address the issue of excess nutrients and reduce harmful and nuisance algae blooms and zones of hypoxia in the Great Lakes.

Key accomplishments:

  • Canada and Ontario have provided funding for partner-led projects that demonstrate effectiveness or increase adoption of best management practices (BMPs) and innovative approaches to reduce phosphorus loads to Lake Erie from agriculture.
    • Under the Sustainable Canadian Agricultural Partnership, the governments of Canada and Ontario have committed over $68 million to the Ontario Agricultural Sustainability Initiative to fund programs that support on-farm improvements to benefit soil health, water quality and carbon sequestration; offer funds to share costs of improving equipment and operations; and extend the ONFARM program that shares knowledge about best on-farm management practices to improve soil health and water quality.
  • Ontario committed $9.5 million over 3 years to improve soil data mapping, soil evaluation and monitoring. This includes creating an Ontario Agricultural Soil Information System to house, manage and analyze soil and agronomy data, and an update to the Soil Resource Inventory to generate critical data for on-farm decisions to improve soil health and farm productivity. Together, these projects will result in improved models and tools to assess risk of excess phosphorus loss from agricultural landscapes and improve understanding of nutrient loadings for key Lake Erie and Lake Ontario tributaries.
  • Under Canada’s Great Lakes Freshwater Ecosystem Initiative, 15 projects have received $54 million in funding to accelerate collaborative efforts to achieve Canada’s Lake Erie phosphorus load reduction targets by 2039. Partner-led projects funded under the initiative will help reduce toxic and nuisance algae by taking action in priority watersheds, applying precision conservation techniques, increasing participation in phosphorus reduction activities, testing innovation and filling knowledge gaps.
  • Over 300 unique activities were implemented by more than 30 partners to support the Canada-Ontario Lake Erie Action Plan (LEAP), Canada and Ontario’s plan to reduce phosphorus loadings to Lake Erie. Examples include on-the-ground efforts to reduce phosphorus loadings in agricultural and urban areas, development and implementation of tailored phosphorus management plans for priority watersheds (such as Thames River, Leamington area tributaries), and development of watershed management plans for the Thames River, Grand River, and Essex Region (including Leamington area). For more information on LEAP implementation, please see the 2024 LEAP Evaluation and Update Report and the LEAP Status of Actions.
  • For the Lake Ontario basin, progress has been made on synthesizing, reviewing and assessing monitoring, research and modelling to calculate phosphorus loads to Lake Ontario and establish binational phosphorus targets for the lake. Following a review of the binational interim phosphorus targets and engagement with partners and stakeholders, Canada and the U.S. agreed to retain the existing phosphorus targets for Lake Ontario.

Annex 2: Harmful pollutants

Purpose: To guide cooperative and coordinated actions to reduce or eliminate releases of harmful pollutants into the Great Lakes basin.

Key accomplishments:

  • Canada and Ontario completed a report on knowledge gained under the previous COA about harmful chemicals. The report identifies gaps in scientific data and informs future reduction actions for Chemicals of Concern and other harmful pollutants.
  • Canada and Ontario worked together to establish guidelines for perfluorooctane sulfonate (PFOS, toxic chemicals known as ‘forever chemicals’) in soil, and a federal and provincial working group has been formed and is drafting guidelines for polycyclic aromatic hydrocarbons (PAHs).
  • Canada and Ontario are reducing plastic pollution in the Great Lakes by supporting capture and cleanup projects and advancing research on sources and control. Various approaches are being used to collect and characterize plastic waste in the Great Lakes including traditional shoreline cleanups, novel in-water technologies that remove plastic litter and debris, and filters for clothes washers to reduce the release of microplastics through wastewater systems. Many of these initiatives share findings and information with the public to enhance awareness of and participation in addressing plastic pollution.
  • Ontario completed its commitment to transition the Blue Box recycling program to a producer responsibility model by passing a regulation.

Annex 3: Wastewater and stormwater

Purpose: Improve the management of wastewater and stormwater to reduce pollution into the Great Lakes.

Key accomplishments:

  • Canada and Ontario are exploring research, monitoring and surveillance actions for the management of at-source and upstream treatment technologies to address harmful pollutants in wastewater effluents and residuals and septic systems.
    • Canada measures chemicals entering and exiting wastewater systems to inform risk management actions and has supported a project to test if granular activated carbon could reduce PFOS and perfluorooctanoic acid (PFOA) emissions from municipal wastewater treatment plants.
    • Ontario is conducting a study on industrial wastewater discharges and is initiating a study of nutrient re-use options for sludge and biosolids from wastewater treatment plants.

Ontario is taking targeted actions to reduce contaminant loadings from stormwater and wastewater systems:

  • Investigating septic systems as sources of nutrients and potential pathways for contaminants, such as excess road salt, to the Great Lakes via groundwater and surface waters.
  • Provided support for the development of tools and resources to encourage the adoption of low impact development practices by stormwater practitioners.
  • Enhancing beach water quality monitoring with real-time and same-day updates for residents and visitors.
  • Helping municipalities protect water quality and reduce contaminants. Ontario is providing nearly $10 million to improve monitoring and public reporting of sewage overflows and wastewater bypasses, and $15 million to enhance stormwater and wastewater discharges to Lake Ontario.

Annex 4: Discharges from vessels

Purpose: Prevent and control vessel discharges that are harmful to the quality of the waters of the Great Lakes, through the adoption and implementation of regulations, programs, and other measures that facilitate coordinated and cooperative implementation and enforcement, where appropriate.

Key accomplishments:

  • Canada published new Ballast Water Regulations in 2021, including standards for ballast water control and management, and timelines for compliance. International ships are required to exchange and manage ballast water before arrival into freshwater areas, like the Great Lakes, and the ballast water of other domestic and U.S. Great Lakes vessels that load or unload ballast water in Canada were regulated in 2024 or will be in 2030, depending on vessel age.
  • The Canadian Coast Guard and their U.S. counterpart signed an update to strengthen the spill response plan that coordinates planning, preparing for, and responding to discharges and releases from vessels in contiguous waters including the Great Lakes.
  • In 2023, Canada launched the Ballast Water Innovation Program which provides funding support to industry-led research into optimizing the use of ballast water management systems in the Great Lakes. Also in 2023, voluntary measures to reduce wastewater pollution from cruise ships were renewed for that operating season. That same year, Transport Canada and the cruise industry developed new permanent measures to reduce wastewater pollution that are enforced through an interim order from June 2023 and a second interim order from June 2024, while new regulations are created.

Priority: Improving coastal areas

Annex 5: Areas of Concern

Purpose: To restore water quality and ecosystem health in Areas of Concern (AOCs).

Key accomplishments:

  • Since the 2021 COA was signed, 9 Beneficial Use Impairments (BUIs) have been successfully redesignated to not impaired in 7 AOCs:
    • Thunder Bay
    • Peninsula Harbour
    • St. Clair River
    • Detroit River
    • Niagara River
    • Bay of Quinte
    • St. Lawrence River
  • Many of these redesignations support the commitment to complete all actions in 6 Canadian AOCs before May 2026.
  • Significant progress has been made in many AOCs:
    • The Thunder Bay AOC restored the beach closings BUI to not impaired due to improved water quality across area beaches.
    • The Peninsula Harbour AOC restored 3 BUIs (fish and wildlife populations, fish and wildlife habitat and degradation of Benthos) based on effective restoration work and monitoring of progress to meet targets.
    • In the St. Clair River AOC, fish liver tumours have been analyzed to assess progress and informed redesignation of the fish tumours or other deformities BUI.
    • In the Detroit River AOC, Canada conducted a comprehensive study evaluating phytoplankton, zooplankton and microbial communities to assess their level of degradation. Results of this study, along with findings of earlier studies, were sufficient to support degradation of phytoplankton and zooplankton populations BUI to not impaired.
    • The Niagara River AOC redesignated the beach closings BUI to not impaired based on water quality improvements and the reduction of beach closures.
    • The Bay of Quinte AOC successfully completed the redesignation of the degradation of aesthetics BUI to not impaired based on demonstrated improvements in environmental targets.
    • The St. Lawrence River AOC was also able to redesignate the beach closings BUI based on improved water quality and meeting targets outlined in the Remedial Action Plan.
  • In the Niagara River AOC, Canada and Ontario have met their commitment to monitor natural recovery in Lyons Creek East. Monitored natural recovery has been effective at reducing concentrations of certain pollutants in downstream creek sections. However, elevated concentrations of polychlorinated biphenyls (PCBs) in sediment and benthic organisms remain in an upstream section of the creek, meaning that additional action is necessary before delisting of the BUI for degradation of benthic communities. To address the situation, Canada and Ontario are working to identify sediment management options for the upper Lyons Creek East site. While all commitments in the 2021 COA are expected to be fully implemented, additional actions will be required to restore all the beneficial use impairments in the Niagara River AOC.

Annex 6: Lakewide management

Purpose: Advance restoration, protection and conservation of the Great Lakes through collaboration among jurisdictions domestically and binationally and with the Great Lakes community on a lake-by-lake basis.

Key accomplishments:

  • Canada and Ontario are working with First Nations and Métis towards developing decision-making processes and application of Traditional Ecological Knowledge under lakewide management. For example, Canada, with support from Ontario, is working with Anishinabek Nation to develop a process for engagement in lakewide management on several lakes. Canada and Ontario have worked with Lake Superior First Nations to support community-based water monitoring actions. Canada has also supported the Métis Nation of Ontario to produce educational videos that raise awareness of Great Lakes issues with Métis in the basin, and Ontario has provided support to the Métis Nation of Ontario’s Great Lakes Advisory Group.
  • Canada, Ontario and many partners have continued to assess the status of Great Lakes water quality and ecosystem health on both basin and individual lake scales by collaboratively conducting routine monitoring activities to support the assessment of the State of the Great Lakes indicators, the nearshore assessment, lakewide management, and to inform action in Great Lakes coastal areas under high stress or of high ecological value.
  • Together with many partners, Canada and Ontario have also advanced implementation of lake-specific coastal initiatives, including the Western Lake Ontario Land to Lake Initiative, the Canadian Lake St. Clair Management Plan, and the Lake Huron Georgian Bay Initiative for Community Action.  Ontario with many partners is advancing the Healthy Lake Huron Initiative.
  • Canada and Ontario have supported Great Lakes communities to participate in decision-making and take actions that support implementation of Lakewide Action and Management Plans (LAMPs):
    • Under the Lake Superior LAMP, a community-based environmental organization supported outreach and engagement with local communities on many issues such as microplastics, stormwater management, climate change adaptation, and invasive species.
    • A First Nation collected water samples and data, determined Indigenous Knowledge baseline indicators for water quality, and provided training to Community Guardians from four other First Nations in the Lake Superior watershed.
    • Canada provided support to a conservation authority that engaged resource management agencies, municipalities, non-government organisations, First Nations, academia, local partners and various other stakeholders in the Lake Erie watershed to participate in co-development of a climate change adaptation strategy to reduce climate change risks and enhance coastal wetland resilience.
    • Ontario supported a community-based association’s efforts to implement and promote stewardship actions and awareness of beneficial management practices in Lake Huron watersheds.

Priority: Protecting habitat and species

Annex 7: Aquatic invasive species

Purpose: Ensure cooperative and coordinated efforts to reduce the threat of aquatic invasive species to Great Lakes water quality and ecosystem health.

Key accomplishments:

  • Federal and provincial agencies are making progress towards a coordinated early detection and rapid respond framework for aquatic invasive species (AIS) in Canadian waters of the Great Lakes. For example:
    • Canada and Ontario are effectively implementing the Invasive Carp Response Plan after an invasive Grass Carp was caught in the Bay of Quinte. This response included notifying partners and developing response efforts.
  • Canada, Ontario and partners continue to actively control and/or eradicate priority AIS in the Great Lakes, including water soldier in the Bay of Quinte and Trent Severn Waterway, marbled crayfish in Burlington stormwater ponds; Hydrilla in the Niagara River, and Grass Carp in Lake Erie and Lake Ontario. Ontario also worked with partners to enable management of established invasive Phragmites throughout the Great Lakes Basin.
  • Canada and Ontario are advancing collaboration with key partners to expand communication networks and strengthen the collective value of outreach activities to reduce the introduction and spread of AIS. This includes engaging First Nations, Métis, the public and stakeholders in activities that build awareness of and prevent the introduction and spread of AIS. For example:
    • Raising awareness about Ontario’s watercraft regulations and regulated species under the Invasive Species Act, 2015.
    • Funding 5 organizations to develop public outreach content about the threat of invasive species and actions the public can take.
    • Collaborating with Great Lakes First Nations communities and the Métis Nation of Ontario to increase capacity for invasive species surveillance and detection through information sharing, workshops and funding.

Annex 8: Habitat and species

Purpose: Continue efforts to restore, protect and conserve the resilience of Great Lakes native species and their habitats.

Key accomplishments:

  • In 2023, Canada and Ontario completed a baseline survey of existing coastal wetland, shoreline, upland and tributary habitats. The survey includes all 4 Canadian Great Lakes, their connecting rivers and the St. Lawrence River. Indigenous communities participated in data testing and identifying priority habitats for conservation, protection and restoration. The same year, Canada and Ontario engaged representatives of over 130 diverse organizations in 8 provinces and 9 U.S. states to share results of the baseline habitat survey and how to access it on an open data portal.
  • Canada and Ontario are working together to assess and address vulnerability of native aquatic species and ecosystems to projected climate changes including variation and trends in temperature and ice cover.
    • Canada, in partnership with Ontario, First Nations and Métis communities, conservation authorities and others, published climate change adaptation options for Great Lakes coastal wetlands. These are being used to inform coastal wetland management decisions and guide the development of priority actions to improve coastal wetland resilience to climate change impacts.
    • Canada and Ontario published a new science-based assessment of Great Lakes coastal wetlands to understand their vulnerability to climate change, estimate wetland sensitivity, and identify wetlands at high risk of degradation and loss. The assessment identified vulnerabilities and adaptation strategies, and supported priority projects aimed at improving resilience of two coastal wetlands near lakes Erie and Ontario.
  • Canada and Ontario took action to inform, engage and involve the Great Lakes community in the restoration, protection and conservation to improve the resilience of native species and habitats. For example, Ontario trained volunteers to monitor endangered Piping Plover nesting success, and to provide outreach to park beach users.
  • Ontario continues to protect, enhance and restore Great Lakes habitat and species by increasing our understanding of fish movement, behaviour and habitat use. Ontario implemented projects focused on walleye, lake whitefish cisco, northern pike, muskellunge, and lake sturgeon in various locations across the Great Lakes. Working alongside partners in the Great Lakes Acoustic Telemetry Observation System (GLATOS), including Canadian federal, U.S. federal and state, First Nations and Métis agencies, Ontario was able to extend the reach of these many projects to track fish moving throughout the entirety of the lakes. The information these studies provide will help to better management habitat and species to ensure the maintenance of healthy ecosystems.

Priority: Enhancing understanding and adaptation

Annex 9: Groundwater quality

Purpose: Gain a better understanding of how groundwater influences Great Lakes water quality and ecosystem health and to identify priority areas for future action.

Key accomplishments:

  • Canada is co-leading a continent-wide project to develop a groundwater and surface water modelling platform that can support risk-based assessments and management decisions in the Great Lakes.
  • Groundwater-surface water exchange maps for southern Ontario have been created and are available for open use. These activities are improving the understanding of groundwater-surface water interactions and their impact on Great Lakes water quality and ecosystem health and can inform management actions and decisions.
  • Progress is being made to identify sources of various contaminants to groundwater, and how they migrate to surface waters of the Great Lakes. In 2023, with support from Ontario, a new project began to identify locations of direct discharge of road salt from groundwater to nearshore areas in the western Lake Ontario basin. Work is already underway to identify sources (such as landfills and septic systems) and pathways for other substances such as per- and polyfluoroalkyl substances to enter surface water from groundwater.
  • In December 2023, Canada and Ontario hosted the first research and priority workshop where federal, provincial and Indigenous representatives discussed ongoing research, priorities, gaps and next steps related to groundwater and surface water science and research.

Annex 10: Climate change impacts and resilience

Purpose: Continue to build understanding of climate change impacts, advance the integration of this knowledge into Great Lakes adaptation strategies and management actions, and help communities build climate resilience.

Key accomplishments:

  • Canada and Ontario are taking steps to improve understanding of observed climate trends and variations, including their effects on the Great Lakes. Canada has implemented a project that has demonstrated critical impacts of climate change this century in Canadian and U.S. portions of the Great Lakes basin. In 2021, Canada hosted 2 climate modeling workshops that engaged academia, federal, provincial and state governments, municipalities, not-for-profit organizations and others to improve understanding of observed climate trends and make information available to decision-makers and the public throughout the Great Lakes basin.
  • Ontario completed data analysis and modelling to shed light on climate change impacts on different stream types and fish communities.
  • Canada and Ontario are working with others to increase implementation of climate change adaptation actions and promote the use of adaptive management tools in the Great Lakes basin. For example, in 2023, Canada and Ontario supported a project with a network of local governments to build community climate change adaptation capacity using guidance materials and training. In collaboration with local governments and organizations, the project included development of a Great Lakes Climate Landscape Assessment and Municipal Guide that helps communities in the basin assess the status of their climate change planning and adaptation. This assessment then assists communities in identifying and addressing information gaps and accessing resources to respond.

Priority: Engaging communities – from awareness to action

Annex 11: From awareness to action

Purpose: Provide opportunities for local community action for the restoration, protection and conservation of the Great Lakes.

Key accomplishments:

  • Canada convened a Canada-United States Great Lakes Public Forum to discuss and receive public input on the state of the lakes, and priorities for science and action. The public forum was held over 3 days in September 2022 in Niagara Falls, Ontario, and included issue-focused panel discussions.
  • Canada and Ontario have supported local community action across the Great Lakes basin.
    • Canada has provided over $15 million in funding for partner-led projects from EcoAction and Great Lakes programs during the first three years of the 2021 COA. For example, $155,000 over 2 years was awarded to a project aiming to engage communities, non-government organizations, First Nations and municipalities in the development of a Great Lakes coastal resilience strategy and regional coastal resilience and management plans.
    • The second round of Ontario’s Great Lakes Local Action Fund provided 36 organizations with funding for projects to protect and restore Great Lakes and connecting rivers. For example, one project in the Lake Huron area involved 133 students and 15 teachers in a litter cleanup event and included local shop students in the design of temporary clean-up stations. Three other projects include an Indigenous partner and/or include content with Indigenous teachings related to the Great Lakes.
  • Since 2021, Canada and Ontario have collaborated to identify locations where improvements can be made to help communities, students and tourists to better connect with and be inspired by the Great Lakes at provincial and national parks, National Marine Conservation Areas and protected areas. Baseline studies have been completed that have assessed current initiatives and opportunities for improvement have been identified at the local level. First Nations and Métis participate on site-specific teams that together develop events, programs, activities and initiatives at individual parks and protected areas.

Annex 12: Métis and the Great Lakes

Purpose: Reflect the interests and important role of Métis as contributors to the restoration, protection and conservation of the Great Lakes.

Key accomplishments:

  • Canada and Ontario have supported Métis by providing opportunities to engage in the implementation of COA, including provincial and federal funding to the Métis Nation of Ontario to raise awareness of Great Lakes water quality and ecosystem health issues with Métis citizens. This includes:
    • Funding to support actions taken by the Métis Nation of Ontario Great Lakes Advisory Group that supports COA results and commitments.
    • Métis participation in Lake Partnership committees for Lakes Superior, Huron and Erie that support delivery of results under COA’s Lakewide Management Annex.
    • Métis citizens have also supported delivery of commitments under the COA Areas of Concern Annex by engaging and providing input into decisions for several Remedial Action Plans for AOCs including Niagara, Thunder Bay, Peninsula Harbour and Jackfish Bay.
  • The federal and provincial co-chairs of the COA Executive Committee have met annually with Métis to discuss Great Lakes issues as well as priorities and actions to achieve COA goals. In addition, a Métis representative has been invited to participate in the Annual Meetings of the COA Executive Committee.

Annex 13: First Nations and the Great Lakes

Purpose: Reflect the interests and important role of First Nations as contributors to the restoration, protection and conservation of the Great Lakes.

Key accomplishments:

  • Canada and Ontario have provided support to First Nations to undertake Great Lakes projects that align with community interests and concernsor example:
    • Canada supported efforts to engage many First Nations communities that rely on eating fish from Lakes Superior or Huron to collect and analyze information about their fish consumption and has supported 45 First Nations-led Great Lakes projects.
    • Ontario has supported efforts by several First Nations around the Lake Superior basin to understand their fish consumption habits and has supported First Nations in the Lake Erie basin to undertake youth stewardship activities in support of the Thames River Shared Waters Approach.
  • Canada and Ontario are working with Anishinabek Nation and have each provided funding for activities that advance shared priorities that align with COA commitments and results, such as:
    • identifying priorities for science and action that will contribute to restoring and protecting water quality and ecosystem health in Lake Huron
    • promoting tools that organizations or individuals can use to deliver community-based science
    • supporting member First Nations’ ability to actively engage and participate in opportunities to inform, guide and deliver Great Lakes collaborative actions
    • providing opportunities for member First Nations to share information from community-led projects
  • The federal and provincial co-chairs of the COA Executive Committee have met annually with First Nations to discuss Great Lakes issues, priorities and actions. In addition, a First Nations representative has been invited to participate in the annual meetings of the COA Executive Committee held to date.

Looking ahead

Canada and Ontario remain dedicated to advancing the implementation of the 2021 COA. Our efforts will continue to build on progress made and address remaining challenges. A second report expected in the 2026-27 timeframe will showcase further achievements and actions initiated to meet the commitments set out in the 2021 COA.