Wetland loss linked to lake pollution

New research by Ducks Unlimited Canada (DUC) has identifi ed that the continued loss of wetlands in Manitoba is increasing phosphorus loads into Lake Winnipeg equivalent to dumping 10 semi-loads of commercial agricultural fertilizer or 544,000 bags of lawn fertilizer directly into the lake every year.

“Never before has DUC’s push to stop the loss of wetlands been so staunchly supported by research,” says Bob Grant, manager provincial operations for Ducks Unlimited Canada. “Our results are by far the most compelling scientific support for the benefits that Manitoba’s wetlands provide to all Manitobans. In fact, this research has broad application across Canada and should be taken seriously by all municipal, provincial and federal governments.”

Up to 70 per cent of wetlands have been lost or degraded in settled areas of Canada. Grant says this has had exceedingly negative impacts on Manitoba’s environment.

To demonstrate how the loss of wetlands impacts the environment, DUC partnered with the University of Guelph and Tarleton State University, a member of the Texas A&M University system to conduct a study of the Broughton’s Creek watershed, located in the Rural Municipality of Blanshard north of Brandon. Lead funding provided by the Murphy Foundation helped complete the first phase of this multi-phase project.

The first step of this project determined that 5,921 wetlands or 70 per cent of total wetlands in the Broughton’s Creek watershed have been lost or degraded due to drainage between 1968 and 2005.

DUC lead researchers Shane Gabor, Pascal Badiou and Lyle Boychuk scaled up the results from the Broughton’s Creek research to represent all of southwestern Manitoba, determining that wetland drainage has caused:

An increase in phosphorus loads into Lake Winnipeg equivalent to dumping 10 semi loads of commercial agricultural fertilizer or 544,000 bags of lawn fertilizer directly into the lake every year.

The release of five million tonnes of carbon to the atmosphere, the equivalent of putting 169,000 cars on the road for 20 years.

An increase in area-contributing run-off into Lake Winnipeg of 4,518 square kilometres, the equivalent of 10 times the size of the City of Winnipeg.

In 2005, nutrient removal and additional carbon released into the atmosphere as a result of lost wetlands are estimated to have cost Manitobans $15 million that year. These estimates are based on the costs associated with removing phosphorus and nitrogen from water and offsetting carbon emissions.

“Given that the province of Manitoba and the city of Winnipeg are investing millions of taxpayer dollars to reduce nutrient loading to Lake Winnipeg and to deal with climate change, stopping the continued destruction of wetlands should be a top priority,” said Pascal Badiou, research scientist, for DUC’s Institute for Wetland and Waterfowl Research. “Maintaining the status quo will significantly reduce the return on investment of our mitigation dollars. This figure will increase to $19 million per year by 2020 if wetland drainage or degradation is not stopped.”

Badiou points out that the costs do not account for the economic costs of downstream flooding, lost biodiversity, diminished ecotourism, lost groundwater recharge and the many other ecological functions that wetlands lose when drained or degraded.

Providing financial incentives for landowners and legislated protection that ensures wetland retention and restoration is needed to prevent further deterioration of Manitoba’s water resources.

“DUC has 70 years of wetland expertise and experience to assist governments and stakeholders in the development of a wetland policy that benefits all Manitobans,” said Grant. “DUC looks forward to working with the government and agricultural community in developing an effective wetland policy for Manitoba.”

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