Working Together to Restore Ecosystem Health

In 1972, in a landmark agreement, Canada and the U.S. signed the Great Lakes Water Quality Agreement (GLWQA). The goal of this agreement is to maintain and restore the physical, chemical and biological health of the Great Lakes Basin ecosystem for now and the future.


The agreement is administered by the International Joint Commission, which was established nearly 100 years ago to settle boundary water disputes on behalf of the two federal governments.


Two important tools have come out of the GLWQA, and the Ministry of Natural Resources has been very active in supporting them. These tools help everyone involved to put the goals of the agreement into practice. They are:

  • Lakewide Management Plans, or LaMPs
  • Remedial Action Plans, or RAPs, that are in place to clean up Great Lakes Areas of Concern, or AOCs


Lakewide Management Plans (LaMPs)

Lake Huron at Killbear Provincial Park
Lake Huron at Killbear Provincial Park - Photo: MNR

Although they are connected, each of the Great Lakes differs from the others, physically, biologically, chemically and geographically. Lakewide management planning is an ecosystem approach that involves federal, provincial and state agencies working together to protect, restore and monitor the ecosystem health of each of the Great Lakes and Lake St. Clair.


LaMPs are now in place for Lake Superior, Lake Erie, and Lake Ontario. Lake Huron has a binational partnership.




Each LaMP describes the state of the lake, the causes of impairment, and the actions that are necessary to restore its environmental health.


Areas of Concern (AOCs)

Lake Superior coastline
Lake Superior coastline - Photo: MNR

Areas of Concern (AOCs) are locations where the water or habitat are so degraded that human health might be affected and healthy fish and wildlife populations may no longer be sustained.  For example, there may be fish deformities, beach closings, and taste or odour problems with drinking water.


AOCs have been identified at various locations throughout the Great Lakes Basin, and 16 have been identified in Canadian waters.

  • On Lake Superior: Thunder Bay, Nipigon Bay, Jackfish Bay, Peninsula Harbour and the St. Mary's River
  • On Lake Erie: St. Clair River, Detroit River, and Niagara river
  • On Lake Ontario: Hamilton Harbour, Toronto, Port Hope, the Bay of Quinte, and the St. Lawrence River at Cornwall

On Lake Huron, two of the lake's most degraded areas – Collingwood Harbour and Severn Sound – have already responded so well to clean up efforts they are no longer listed as AOCs. A third site – Spanish Harbour – has also responded well and is now considered to be an Area of Natural Recovery. 


In April 2010, Canada and Ontario celebrated the removal of Lake Erie’s Wheatley Harbour from the list of Great Lakes Areas of Concern. Today, the ecosystem is restored. Fish and wildlife populations in Wheatley Harbour are healthy. The fish community is abundant and diverse and water quality has improved.


Canada, Ontario and community partners have also completed all actions to restore environmental quality in the St. Lawrence River at Cornwall, and Jackfish Bay on Lake Superior, and are consulting with those communities on the next steps.


Many partners – including the Ministry of Natural Resources – work together to clean up Great Lakes’ AOCs.