Science Response 2014/031

Lake Winnipeg Zebra Mussel treatment

Context

The Zebra Mussel (Dreissena polymorpha), a native of the Black and Caspian seas region in Southeastern Europe, has a long history of invasion in freshwaters of both Europe and eastern North America. This species was introduced to the Laurentian Great Lakes in the mid-1980s as a result of ballast water discharge from ships. The mussel has rapidly dispersed throughout the Great Lakes region, into river systems, and smaller lakes and reservoirs. The species has had a large economic and ecological impact where it has become established, resulting in severe negative impacts on food webs and nutrient processing. Zebra Mussel was first discovered in the Red River basin in the United States in about 2009. In October 2013, the species was first reported in Lake Winnipeg, Manitoba.

The Province of Manitoba has implemented a Rapid Response Protocol based on Locke and Hanson (2009) in an attempt to eradicate known populations and suppress the spread of the species. To that end, they have requested the closure of four Small Craft Harbours in Lake Winnipeg for a period following ice-out in spring 2014 to apply a liquid potash treatment to kill Zebra Mussel found there.

Fisheries and Oceans Canada’s (DFO) Small Craft Harbours has requested Science information and advice on this request. Advice is required by April 22, 2014 to allow the Department time to evaluate the province’s request and make a decision about closing the harbours.

Specifically, DFO Science has been asked the following questions:

1. Does DFO Science support the Manitoba Zebra Mussel Science Advisory Committee's recommendation to eradicate/suppress Zebra Mussel at four Small Craft Harbour sites on Lake Winnipeg by isolating the harbours and applying a liquid potash treatment? 
2. If yes, does DFO Science support the recommended timing window for the eradication/suppression treatment to be carried out (i.e., immediately following ice-out but before water temperatures reach 10°C)? 
3. Has DFO Science identified and reviewed alternative treatment options?

This Science Response Report results from the Science Response Process of April 2014 on the review of the proposed treatment for Zebra Mussel in Lake Winnipeg.

Complete document (PDF, 782 KB)

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