BC watershed declared to be infected with disease that is deadly to fish populations

It's been about six months since BC recorded its first-ever case of a disease that has a high mortality rate in fish populations and a watershed in the eastern part of the province has been declared as an infected area.

On Monday, the Canadian Food Inspection Agency (CFIA) confirmed that the Columbia River watershed is now infected with the disease.

Whirling disease was first detected in early December and by late January, lakes in Yoho Park were closed due to the detection of the disease.

The declaration is meant to help the CFIA to prevent the spread of whirling disease through controlling certain movements that pose a risk of spreading the disease.

A domestic movement permit will be required from the CFIA for susceptible species, a statement from the agency says.

“Good practices such as cleaning, draining and drying your gear before moving between water bodies are very important to prevent spread of whirling disease and other invasive species,” the agency says.

“This also helps to keep the parasite level as low as possible to minimize the impact of this disease on all susceptible finfish species.”

According to the CFIA, the rest of BC has been declared as a buffer zone for the disease.

The Columbia Shuswap Invasive Species Society (CSISS) says whirling disease as a devastating condition brought on by a microscopic parasite that primarily targets trout and salmon.

The disease damages the backbone of the fish, causing skeletal deformities in the bodies or heads, for example, shortening the mandible or causing indentations on their heads.

Infected fish display a “distinctive and distressing” ‘whirling’ swimming pattern, often leading to premature mortality.

According to the federal government, overall deaths of infected fry and fingerlings can reach 90%.

There are no treatment options currently available.

Whirling disease is not a risk to human health or other mammals, the agency says.