Invasive mussel prevention timeline

2017: Parks Canada implemented a prohibition on the use of motorized and trailer-launched watercraft, following the discovery of invasive mussels in Montana, to ensure the ongoing ecological integrity of Waterton Lakes National Park. At that time it was the most effective method to safeguard the ecological health of park’s waters from the devastating and permanent ecological and economic impacts of invasive mussels.

2018: Improvement District #4 council’s Clean Lake Initiative proposes a 90-day quarantine seal for motorized watercraft – a length of time sufficient to prevent the introduction of invasive mussels to park waters. Their proposed solution meets Parks Canada’s standards, and sealing will begin in fall 2018.

2019: Motorized and trailered watercraft will be permitted to operate in Upper and Middle Waterton Lake for the 2019 boating season once they have completed a 90-day sealed quarantine.

How invasive mussels spread

Invasive mussels are originally from Europe and were first introduced into North America in the 1980s. The fingernail-sized freshwater mollusk can produce millions of eggs and easily attach itself to objects such as boats. Their numbers can reach tens of thousands per square metre.

Invasive mussel-encrusted boat
Photo: U.S. National Park Service

As prodigious filter feeders, they strip nutrients from the water leaving little or no food for native species. This affects the entire food web, impacting plant and animal life in the region, and altering water chemistry and clarity. They cause extensive economic and visitor experience impacts by clogging water intake structures, dams, water treatment facilities, hydro power facilities, docks, breakwaters, buoys, boats and beaches.

Infestations are permanent and irreversible. No method, technology or natural predator exists to remove invasive mussels once established in a water body.

The biggest risk of invasive mussel infestation is transmission downstream from infected waters and transfer from infested areas in motorized and trailer-launched watercraft. Prevention is key to minimize the risk. The best available evidence shows a 90-day quarantine is sufficient to prevent invasive mussels from being introduced to Waterton Lake.

Mussels and other aquatic invasive species can inadvertently be moved to a new location attached to boats, equipment, and trailers. Standing or trapped water in boats is a concern because invasive mussels have a microscopic larval stage, allowing them to be present without being visible. Boaters are reminded to Clean, Drain, Dry their watercraft as well, as this is a critical preventative measure.

Invasive mussels are found in Quebec, Ontario, Manitoba, and 34 U.S. states, including Montana.

The threat of invasive mussels to Waterton Lakes National Park

Invasive mussels pose a significant and irreversible threat to the integrity of park waters. An infestation would severely impact the park’s ecology and recreation experiences.

The Waterton Lakes have a unique ecology. In addition to serving as habitat for bull trout (a threatened species), they are the only known lakes to contain the assemblage of lake trout, pygmy whitefish, and rare glacial relic species such as opposum shrimp and deepwater sculpin. The pygmy whitefish found in these lakes are considered a unique population and designated Special Concern by the Committee on the Status of Endangered Wildlife in Canada. Upper Waterton Lake is the only known location of deep water sculpin in Alberta.

In addition, with the headwaters of the South Saskatchewan River Basin located in Waterton Lakes National Park, an invasive mussel infestation in the park could threaten irrigation networks for southern Alberta’s agricultural industry, water infrastructure for numerous jurisdictions including the cities of Lethbridge and Medicine Hat, and other recreational areas.

Parks Canada will continue to manage the aquatic integrity in Waterton Lakes National Park through monitoring, public education, and inspection and permit programs for motorized and non-motorized watercraft alike. In addition, staff, outside researchers and contractors must follow best practices and a strict decontamination protocol for gear and equipment when working in park waters.