Whirling disease puts a damper on aquaculture ops in Canadian province

The future is uncertain for aquaculture operations in Alberta, Canada after the government ordered them quarantined after a deadly parasite affecting salmon and trout was found in Canadian waters for the first time.

         The Canadian Food Inspection Agency (CFIA) confirmed the presence of whirling disease in fish in Johnson Lake in Banff National Park on August 25. This was the first case of whirling disease in Canada.

         On September 6, the Alberta Environment and Parks ordered the quarantine of all commercial fish culture operations as a precaution. The province has also temporarily ceased provincial fish stocking.

         The parasite, Myxobolus cerebralis, affects salmonid fish, including trout, salmon and whitefish. One of the signs of the disease caused by the parasite is a marked “whirling” swimming behavior in fish as the parasite invades cartilage and impairs the nervous system.

         The quarantine is in effect until individual fish farms and hatcheries licensed for salmonids are tested and found negative for the disease. Several fish farms in the province have been tested and cleared as of December but testing of other farms continues.