B.C. imposes new rules on boaters to stop spread of parasite

British Columbia's chief veterinarian has issued an order making it illegal to transport boats or other watercraft without removing the drain plug to prevent the spread of whirling disease.

Whirling disease, which is fatal in fish, is caused by a microscopic parasite that mainly targets salmon and trout. The Ministry of Water, Land and Resource Stewardship says the order takes effect on Friday and is also intended to keep invasive mussels out of B.C. waterways.

Boat operators are required to clean, drain and dry all watercraft and remove all mud, sand and plants before leaving the shore. 

Vessels will also have to dry out for at least 24 hours before entering new waters. 

The ministry says inspectors will be checking watercraft for compliance with the new orders.

Whirling disease causes deformities in fish and has a high mortality rate but poses no health risk to people swimming in or drinking water that contains the parasite responsible for the condition.

The disease causes fish to swim in unusual circular patterns. Juvenile fish are most susceptible to the parasite. There is no treatment to eradicate the disease.

In August 2016, the first known case of whirling disease in Canada was detected in Johnson Lake in Banff National Park. The following year, Parks Canada officials caught and killed all the fish in the 15-hectare lake to stop the spread of the disease.

The first case of whirling disease in B.C. was confirmed in Yoho National Park in December 2023. All water bodies in the park have been closed until March next year. 

In March, in an effort to slow the spread of the parasite, Parks Canada also closed all bodies of water in the Kootenay National Park and restricted watercraft in Alberta's Waterton Lakes National Park.

Earlier this month, the Canadian Food Inspection Agency declared the Columbia River Watershed an infected area. The agency says it now requires permits for activities including transporting used aquaculture equipment and moving fish or sediment samples for testing. 

According to the agency, fish infected with whirling disease can be eaten safely.