The following article is from an archived newsletter. See our Shared Waters newsletter.

Recommendations Intended to Protect Champlain-Missiquoi and Memphremagog from Harmful Algal Blooms

Picture of Michele D'Amours
Michele D’Amours
cyanobacteria missisquoi

Public concerns regarding water quality and harmful algal blooms in Lake Champlain-Missisquoi Bay and Lake Memphremagog have continued to grow over the past decade. The International Joint Commission (IJC), in response to a request from Canadian and United States governments, has issued a report with recommendations on how federal, state, provincial and local governments can work together to clean up the water.

Harmful algal blooms produce toxins that can affect human health, pets, ecosystems and wildlife. They also impact recreational activities in the summer, local economies and threaten the safety of drinking water. The blooms occur due to high phosphorus levels in the lakes from sources including cities and farms.

The problem prompted the Canadian and US governments to ask the IJC to further study the issue in October 2017.  

The IJC released its final report to the governments in April. The IJC appointed two study advisory groups and collaborated with watershed organizations, local governments and the academic community to review existing information and gather the latest research. The final document includes technical reports and recommendations from the study advisory groups.

Recommendations were made by the IJC in partnership with the Lake Champlain Basin Program, l’Organisme de basin versant de la baie Missisquoi, Memphremagog Conservation Inc. and the Memphremagog Watershed Association.

Getting feedback from the public also was an important element of the IJC’s study. Workshops, consultations and public meetings were held in the fall of 2019 in Venise-en Québec, Québec, and St-Albans, Vermont. Comments from the public were integrated into the reports.

Lake Memphremagog. Credit: IJC

The IJC endorsed the advisory group recommendations and added four recommendations to accelerate the recovery process. It’s estimated the efforts would take from two-10 years to complete, based on the specific recommendations from the IJC’s report:

Strengthen current government efforts: Federal governments should accelerate the pace of recovery and protection by working with provincial, state, local and indigenous governments to strengthen current efforts to systematically implement the recommendations in the report.

Improve existing governance mechanisms: Federal governments should provide resources to support existing provincial, state and local governance mechanisms that coordinate binational oversight of the basins to more effectively sustain long-term management of joint efforts and actions.

Understand nutrient inputs and outputs: Federal governments should assist in providing an improved understanding of nutrient input and outputs in each of the two basins. By harmonizing provincial, state and local science and data collection efforts, governments can create a comprehensive binational mass balance model showing where nutrients are coming into the two lakes, how they move through the water and where they’re going. This information can enable jurisdictions to efficiently and effectively evaluate and manage measures to mitigate nutrient loading into the water.

Develop and initiate implementation of basin-specific action plans: Federal governments should work with provincial, state, local and indigenous governments to develop and implement basin-specific, binational, 20- to 30-year sustained action plans to address nutrient loading in both basins.

The proliferation of harmful algal blooms is a universal problem and there are no easy fixes. It will now be up to the Canadian and US governments to determine which of the Commission’s recommendations will be implemented to address water quality issues in Lake Champlain-Missisquoi Bay and Lake Memphremagog.

To learn more about the review of nutrient loading and impacts in lakes Champlain and Memphremagog, visit The IJC also is undertaking a Lake Champlain-Richelieu River Flooding Study and information can be found at


Picture of Michele D'Amours
Michele D’Amours

Michele D’Amours is a senior communications adviser at the IJC’s Canadian Section office in Ottawa, Ontario.

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