Following the recent discovery of whirling disease in Alberta, Trout Unlimited Canada has launched a campaign called “Stop the Spread”. The campaign is focused on preventing the spread and impact of invasive species and pathogens that threaten Canada’s fisheries. While whirling disease may be front of mind in Alberta, other jurisdictions in Canada are currently dealing with zebra mussels, Asian carps, spiny water flea, Viral hemorrhagic septicemia (VHS) and other invasive species and pathogens that can have population-level effects on wild fisheries.

Whirling disease affects salmonid fishes (trout, char, whitefish, salmon) and can cause very high mortality rates. The disease is caused by a microscopic parasite Myxobolus cerebralis that requires two hosts: a Tubifex worm and a salmonid fish. The parasite affects a fish’s nerves and damages cartilage, which can cause the fish to swim in a whirling or tail-chasing behaviour. Whirling disease was first described in Europe over 100 years ago and was introduced to North America over 50 years ago. Since then, whirling disease has been implicated in severe population declines of wild trout in many water bodies across North America. This pathogen can lay dormant in mud for a decade, which makes identification of the original source near impossible. Until summer 2016, whirling disease had not been detected in Canadian rivers, lakes or streams.

Once the parasite causing whirling disease is present in an environment, it is considered impossible to control or eradicate. However, there are many strategies to prevent the spread. Much research has been done but there is still work to do to better understand the parasite, improve management strategies, and stop the spread to protect our wild fish populations.

You can donate directly to our Stop the Spread campaign by selecting Stop the Spread option in the Donation Details drop-down choices when you Donate below.