Suspected whirling disease forces closure of lakes in Kootenay and Yoho National Parks

Rainbow trout occupy a pond at Rushing Waters Fisheries, Tuesday, July 3, 2012 in Palmyra, Wis. (Wisconsin State Journal-John Hart/AP/THE CANADIAN PRESS)

All bodies of water in Kootenay and Yoho National Parks have been closed for the next five months after a suspected case of whirling disease was reported in British Columbia's southeast Rocky Mountains.

Parks Canada says in a news release it's the first time the microscopic parasite that causes the fatal disease in fish has been detected in the province.

The agency says it is closing Emerald Lake, Peaceful Pond, Lone Duck Pond and the Emerald River's shorelines, water bodies and tributaries until March 31, 2024, to limit further spread.

It said in an earlier statement that once established it's nearly impossible to eradicate the parasite, which is a known aquatic invasive species.

Parks Canada says officials are conducting further sampling on the Kicking Horse and Kootenay rivers, but preliminary test results found suspected cases of whirling disease in the Kicking Horse River, Wapta Lake, Finn Creek, Monarch Creek and the confluence of Emerald River and the Kicking Horse River.

The Canadian Food Inspection Agency says on its website that whirling disease impacts various species of trout and salmon as well as mountain whitefish, is particularly deadly for younger fish and can also cause skeletal deformities.

Though the CFIA says the disease does not pose a risk to human health, people can accidentally spread it.

This report by The Canadian Press was first published Oct. 26, 2023.