All water bodies closed in 2 B.C. national parks due to parasite

Parks Canada is closing all bodies of water in British Columbia's Kootenay and Yoho national parks, and restricting watercraft in Alberta's Waterton Lakes National Park, in an effort to slow the spread of invasive species.

The lakes, creeks and tributaries in eastern British Columbia will be closed until at least March next year in response to the deadly whirling disease parasite found in fish.

At the same time, non-motorized watercraft from outside park boundaries will not be allowed into Waterton Lakes National Park in southern Alberta, to protect against both whirling disease and invasive zebra and quagga mussels.

This is an extension and expansion of a closure first put into place in October 2023.

British Columbia's first case of whirling disease was detected in Emerald Lake last year and was later found in Kicking Horse River, Wapta Lake, Finn Creek, Monarch Creek and the confluence of Emerald River and the Kicking Horse River.

Access was first restricted for five months beginninglast October, and Francois Masse, Parks Canada's superintendent for Lake Louise, Yoho and Kootenay, says extending the restrictions another year will help protect fish species including several types of trout and kokanee salmon.

Locke Marshall, the superintendent for Waterton Lakes National Park, says along with the ban on non-motorized watercraft from outside park boundaries, fishing for all species will no longer be permitted in flowing waters in the park, but will be allowed under current regulations in park lakes.

Sacrifice some fish to save the others: biologist

Whirling disease has a devastating impact on aquatic life.

Once established, researchers say, it is impossible to eradicate the parasite, which is a known aquatic invasive species. Parks Canada says the mortality rate for young fish is 90 per cent, with no treatment options available.

In August 2016, the first known Canadian case of whirling disease was detectedin Johnson Lake, in Banff National Park. In aneffort to stop the spread of the parasite, officials began to pull the fish from the lake and eventually they all had to be killed.

Juan Jos Alava, principal investigator for the ocean pollution research unit at the University of British Columbia, said in a 2023 interview that would be the likely outcome in B.C., as well.

"The best thing they can do is collect all the fish and basically sacrifice them," he said at the time.

Alava said killing the fish, which include salmon and rainbow trout, will have a major impact on fishers and Indigenous groups in the area but the alternative is for the disease to spread even further.

He explainedafter the fish die prematurely,the parasite'sspores remain in the environmentand contaminate the water's sediment.