Aquatic invasive species in Waterton Lakes National Park

Many of Waterton Lakes National Park’s thousands of visitors enjoy the park’s lakes and rivers each year by boating, fishing, and swimming. These activities risk introducing aquatic invasive species (AIS) into park waters. AIS are non-native species, exotic species, noxious weeds, or invasive pests or pathogens that require aquatic habitat to survive. Many kinds of aquatic invasive species can survive in Waterton Lakes National Park and interrupt our ecosystem. Some species of concern are zebra and quagga mussels, whirling disease, and Eurasian milfoil.

Invasive mussels

Zebra and quagga mussels are 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 are of the highest concern, and many other jurisdictions have taken action to prevent their spread. Infestations are permanent and irreversible.

Whirling disease

Whirling disease affects salmonid fish like trout and whitefish and can cause them to swim in a whirling pattern and die prematurely. Whirling disease is present in the Oldman River basin, including downstream from the park in the Waterton River below the reservoir. This disease would be very detrimental to the park’s native fish populations.

Eurasian water milfoil

Eurasian water milfoil is a perennial, submersed aquatic plant native to Eurasia and North Africa. This invasive plant is currently not present in Alberta, but, new colonies can be formed from a single stem, seed, or leaf. Eurasian milfoil forms thick layers that shade native plants and decrease oxygen levels as they decay, impacting native fish and wildlife. It can be very difficult to eradicate once established.