Archived News Releases

News Release - Manitoba

May 14, 2014

Province Announces Lake Winnipeg Zebra Mussel Treatment and Control Project Implementation Information

Local Fishers, Officials, Community Consulted: Minister Mackintosh

Following a consultation process with key stakeholders, the Manitoba government has finalized its plan for the treatment of zebra mussels in four harbours on Lake Winnipeg to ensure continued access to Lake Winnipeg for commercial fishers, Conservation and Water Stewardship Minister Gord Mackintosh announced today.

“We need to take immediate action to combat the threat of a zebra mussel infestation in Lake Winnipeg and have developed an innovative solution to treat the harbours while still allowing commercial fishers to have access to the lake,” Minister Mackintosh said.  “Fishers and boaters are important partners in this effort to control zebra mussels before they spread further and cause permanent damage to the ecosystem or to Manitoba waterways.”

A zebra mussel infestation has been identified in four harbours:  Gimli Harbour, Silver Harbour Marine Resort/Arnes Harbour, Boundary Creek Marina/Winnipeg Beach Harbour and Balsam Bay Harbour in the south basin of Lake Winnipeg.  Additional inspection this spring has confirmed the zebra mussels survived the winter.

The zebra mussels will be fought by applying liquid potash to harbour waters, the minister said.  This treatment has been proven effective against zebra mussels, while it does not impact fish, will not discolour water, and will not result in any odour, he added.  Work will be undertaken by the ASI Group Inc.

“Like the other commercial fishers in the areas of the four harbours being treated for zebra mussels, I appreciate our leaders and Minister Mackintosh’s efforts to accommodate our immediate need to catch fish by allowing harbour access, while taking this bold move to protect our fishery and our lake for all Manitobans, now and into the future,” said Bill Buckels, Gimli commercial fisher and community representative.  “I realize now more than ever, how important it is for all Manitobans to take action on the problem of zebra mussels and to be more careful in the future about monitoring and spreading this problem.”

Preparations for the treatment will begin on or shortly after May 20 depending on weather.  To minimize any disruption to the local fishers, the province will install a gated silt curtain that will keep the liquid potash in the harbour, but can be opened to allow fishers to get in and out of the harbour.  The only exception is Balsam Bay Harbour, which is too shallow to accommodate a movable curtain so a full containment curtain will be installed.  Minister Mackintosh said the process may have to be adjusted if the ice has not moved off the lake, but at this time the estimated treatment schedule is:

  • Boundary Creek Marina / Winnipeg Beach Harbour:
    • installation of the gated silt curtain:  May 21 to 22 
    • charging of harbour waters with liquid potash:  May 23 to 25
    • estimated treatment completion date:  June 3
  • Silver Harbour Marine Resort/Arnes Harbour:
    • installation of the gated silt curtain:  May 23 to 24  
    • charging of harbour waters with liquid potash: May 26 to 28
    • estimated treatment completion date:  June 6
  • Gimli Harbour:
    • installation of the gated silt curtain:  May 25 to 27
    • charging of harbour waters with liquid potash: May 29 to June 1
    • estimated treatment completion date:  June 10
  • Balsam Bay Harbour:
    • installation of the gated silt curtain:  May 28 to 29
    • charging of harbour waters with liquid potash: June 2 to 3 
    • estimated treatment completion date:  June 12.

The timing and estimated completion is dependent on ice being off the harbour at the proposed start date and the water temperature during the treatment process, the minister said.  Warmer water will result in a shorter treatment period.  If full eradication of the zebra mussels occurs earlier than the estimated treatment completion date, the harbours will be opened earlier for all boat traffic.

“Zebra mussels have devastated shoreline communities on the Great Lakes, such as Lake Ontario, and those lakes, once enjoyed and used by generations of families, are never to return to what they were,” said Mayor Steve Strang, the R.M. of St. Clements.  “That same pressure is now before us a‎ll, let us not lose what we have, as other communities have, but let us support the role our government has taken to try to stop the invasion of zebra mussels.  The only solution will come from us all working as one.”

During the treatment, harbour users are asked to be aware of the following operational considerations:

  • recreational and non-commercial boats can be launched and moored in the infested harbours before and during the treatment process, and harbour user and public access to harbour docks will not be restricted during the treatment process once the potash has initially been applied;
  • the gated curtain will allow the Coast Guard and search and rescue boats, subsistence and commercial fishers’ boats in and out of the harbour;
  • recreational boaters are asked to remain in the harbour as much as possible during treatment to reduce gate operation and some larger-keeled recreational boats may have to remain in harbours at all times, depending on water levels relative to the gates; and
  • the gate will have clear signage, be supervised and operated by staff according to operational guidelines provided to the Harbour Authority. 

Public information sources for zebra mussels and aquatic invasive species can be found at or call 1-87-STOP AIS-0 (1-877-867-2470) (toll-free).

The minister reminded boaters to do their part to help avoid the transfer of aquatic invasive species.  If your boat or other equipment was not dry-docked over the winter, it should be taken out of the water for at least 18 days in the spring, five days in the summer or washed using high-pressure, very hot water – preferably 50°C (120°F) for two minutes or longer.

To comment on the application of potassium chloride, please contact:

Manitoba Conservation and Water Stewardship

Pesticides and Hazardous Waste Section

Suite 160, 123 Main St.

Winnipeg, MB  R3C 1A5

 - 30 -