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Wetlands
Loss and Fragmentation of Wetlands along the Great Lakes–St. Lawrence Shoreline
Outlook
Wetlands across the Great Lakes–St. Lawrence River Basin are being monitored using indicators selected to reveal their condition. Binational (Canada–United States) Great Lakes programs are developing standardized monitoring systems. The State of the Lakes Ecosystem Conference (SOLEC) is a biennial conference hosted by Environment Canada and the United States Environmental Protection Agency, providing independent reporting on the state of health of the Great Lakes Basin ecosystem.
In addition, five government partners — Environment Canada, Quebec's Ministère du Développement durable, de l'Environnement et des Parcs and Ministère des Ressources naturelles et de la Faune, Fisheries and Oceans Canada, and the Canadian Space Agency — are pooling their expertise and efforts to provide Canadians with information on the state of the St. Lawrence River and its long-term trends.
Current wetland data coverage of the St. Lawrence is good, as most of the shorelines between Cornwall and Quebec City have been mapped. However, downstream of Quebec City, shoreline wetland data are sparse and incomplete.
Current wetland data for the Great Lakes north of the Canadian Shield is limited. Complex shorelines such as those in the Lake Huron and Georgian Bay region contain a number of large archipelagos that support many small, protected wetlands. Identification and delineation of these wetlands using traditional aerial photographic interpretation techniques is very difficult. Accurate mapping of these areas will require the use of remote sensing technologies. Another limitation of current monitoring activities is the exclusion of submerged aquatic vegetation. This shoreline wetland class has typically been delineated according to the amount of visible wetland, based upon air photo interpretation or remote sensing imagery. A drawback to these methodologies is that most submerged aquatic plants are not accurately reflected in the wetland boundary. In the future, improvements to bathymetric survey methodologies and imagery techniques, resolution and availability will provide more accurate estimates of wetland boundaries.
The need for a comprehensive database of wetlands in the Great Lakes–St. Lawrence Basin has been well documented. Progress has been made by linking existing databases and classifications to allow a uniform picture of the entire Great Lakes–St. Lawrence system to emerge. However, considerable work is still required to improve classification standards across political boundaries, address regional information gaps and develop protocols to enable monitoring and reporting in the future.
Progress to Come
Great Lakes Coastal Wetlands Consortium
There is currently no co-ordinated long-term monitoring of Great Lakes shoreline wetlands. The Great Lakes Coastal Wetlands Consortium is a group of U.S. and Canadian scientists, policy makers and others dedicated to designing a long-term program to monitor Great Lakes wetlands, including developing monitoring protocols and creating a binational database accessible to scientists, decision-makers and the public. Brought together by the Great Lakes Commission in November 2000, with funding from the U.S. Environmental Protection Agency, the consortium is designing and validating shoreline wetland indicators recommended at SOLEC 1998. Environment Canada has been actively involved in the consortium.
Priority indicators for development within this initiative include type of shoreline wetland area and plant community health. The response of Great Lakes shoreline wetlands to stress varies significantly, depending on their geomorphology and hydrologic connectivity to the lakes. For this reason, the consortium is focusing on classifying wetlands using a hydrogeomorphically-based system. A standardized binational vegetation-based classification system and monitoring methodology has yet to be developed and remote sensing options are being explored.
State of the St. Lawrence Monitoring Program
Environment Canada has developed expertise in using remote sensing technology to produce high-resolution wetland maps of the stretch between Cornwall, Ontario, to Montmagny, Quebec. A St. Lawrence River wetland monitoring project was implemented in 1996 to update understanding of the state and dynamics of wetland vegetation. Several satellite and airborne remote-sensing technologies are used to acquire shoreline images of St. Lawrence wetlands. However, a hydrogeomorphic wetland classification system has not been applied in the St. Lawrence River.
Wetland plant community health indicator metrics are also being developed. Presence, abundance and change in wetland plant communities and invasive species have been identified as potential metrics within this indicator. Work has recently begun on implementing a specific monitoring program for invasive plant species.
Environment Canada has begun the process of developing integrated approaches for monitoring in the Great Lakes–St. Lawrence Basin. However, additional focused efforts would be valuable to:
- harmonize wetland and plant community classifications;
- begin to develop a common understanding of objectives, methods and expected results on the problem of invasive plant species; and
- provide comparable results and linkages among wetland indicator monitoring activities in the Great Lakes and the St. Lawrence regions.
The Great Lakes–St. Lawrence Basin continues to support a diverse and extensive array of wetlands that shelter hundreds of ecologically and socially important plant and wildlife species. Large-scale conservation initiatives, changing public perception and public policy initiatives to improve wetland protection have significantly slowed the rate of wetland loss in recent decades. However, wetland areas continue to be eroded and there is increased concern over continued degradation of wetland quality due to land-use intensification within shoreline wetland watersheds. Large, multi-partnered monitoring initiatives currently underway extend beyond political boundaries and are resulting in the development of basin-wide wetland monitoring standards. Collaboration between wetland monitoring programs based in the Great Lakes and the St. Lawrence River will ensure that basin-level reporting continues to improve in the future.
Wetland Stresses |
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Wetlands are under stress at all times, from naturally occurring phenomena such as storms, to human disturbances such as draining and filling. Wetlands benefit from some degree of stress. For example, water-level fluctuation can lead to increased diversity of plant communities. On the other hand, many stresses are detrimental to wetland area and function. Stresses can be direct or indirect. Direct stresses, such as draining and filling, originate in the wetland itself and are therefore easy to pinpoint. The causes of indirect stresses are often physically removed. Indirect stresses include urban and agricultural runoff, and acid rain, all of which are difficult to control due to their diffuse and variable sources. Indicators are an excellent way to assess the level of stress in different areas and to track improvement or deterioration. |
To Learn More
ENVIRONMENT CANADA. 2002. Where Land Meets Water: Understanding Wetlands of the Great Lakes. Toronto: Environment Canada. 72 pp.
ENVIRONMENT CANADA and CENTRAL LAKE ONTARIO CONSERVATION AUTHORITY. 2004. Durham Regional Shoreline Wetland Monitoring Project: Year 2 Technical Report. Report ECB-OR. Downsview, Ont. 177 pp.
ENVIRONMENT CANADA – ONTARIO REGION. State of the Lakes Ecosystem Conference (SOLEC). <URL:http://www.on.ec.gc.ca/solec/>.
ENVIRONMENT CANADA – ONTARIO REGION. Wetlands of Ontario. <URL:http://www.on.ec.gc.ca/wetlands/>.
ENVIRONMENT CANADA – QUEBEC REGION, ST. LAWRENCE CENTRE. Changing Surface Area of Wetlands. <URL:http://www.qc.ec.gc.ca/csl/inf/inf014_e.html>.
ENVIRONMENT CANADA – QUEBEC REGION. St. Lawrence Vision 2000. <URL:http://www.slv2000.qc.ca/>.
GRATTON, L. and C. DUBREUIL. 1990. Portrait de la végétation et de la flore du Saint-Laurent. Quebec City: Ministère de l'Environnement, Direction de la conservation et du patrimoine écologique. 56 pp.
JEAN, M., G. LÉTOURNEAU, C. LAVOIE, and F. DELISLE. 2002. Freshwater Wetlands and Exotic Plant Species. Fact sheet in the series “Monitoring the State of the St. Lawrence River.” Environment Canada – Quebec Region, Environmental Conservation, St. Lawrence Centre, and Laval University, Centre de recherche en aménagement et développement.
ST. LAWRENCE CENTRE. 1996. State of the Environment Report on the St. Lawrence River. Volume 1: The St. Lawrence Ecosystem. “St. Lawrence UPDATE” series. Montreal: Environment Canada – Quebec Region, Environmental Conservation, and Éditions MultiMondes.
Prepared byJoel Ingram and Krista Holmes Martin Jean, Guy Létourneau, and Caroline Savage
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Date modified: 2008/05/01 – Important Notices
