By now, anglers across Canada have heard that for the first time ever, Whirling disease as been confirmed in Alberta. On August 23rd, 2016, the Canadian Food Inspection Agency (CFIA) confirmed Whirling disease in arguably one of the greatest trout fishing countries and provinces in the world when a fish from Johnson Lake, Alberta, located inside the Banff National Park was tested and confirmed positive for Whirling disease.
Whirling disease has been observed and monitored in the United States since the early 1950s and in New Zealand, since the 1970s. In Europe and Asia, where it’s believed to have originated, there is no recorded date.
According to experts, Whirling disease greatly affects fry, fingerlings, and juvenile in (salmonid) fish species such as salmon and trout. The disease is caused by a microscopic parasite called (Myxobolus Cerebralis). The disease causes skeletal deformation and similar to Chronic Wasting disease in affected deer and elk, Whirling disease causes neurological deterioration. As the disease progresses in an affected fish, instead of the fish swimming in a natural swimming motion, affected fish swim in an awkward corkscrew motion thus, the name Whirling Disease. Affected fish will eventually have trouble feeding and may even starve to death. Affected fish are also extremely vulnerable to predator fish and birds of prey. It’s believed that the mortality rate within fingerlings and juvenile trout and salmon species affected by the disease is as high as 90%. Fish that do survive with the disease from the juvenile stage may be obviously deformed from the parasites that live within their skeletal system and cartilage.
Larger more mature fish are often more tolerant of the disease and often don’t show signs of the disease. They generally don’t die from the disease and live a normal life span. However, larger more mature fish can still be carriers of the disease and in a worst case scenario, juvenile fish will never reach sexual maturity and over time greatly affecting the fish population within the water body.
The spores that make up Whirling disease are extremely hardy. Through a variety of scientific lab testing of the spores, tests have proven that the spores can withstand -20° Celsius temperatures for up to three months. The microscopic spores are also durable enough to be consumed through water and vegetation by waterfowl and pass through the waterfowl digestive system alive and be transported to other water bodies through waterfowl waste. They can also infect a healthy fish that consumes an infected fish. The spores can also live in a dead fish for long periods of time and be released back into the water body as the dead fish decays. The spread of these deadly spores is greatly increased in river and stream systems as the current moves them downstream much faster spreading the spores as the current flows.
Everyone is reminded to clean any gear that comes in contact with the water.
The spores can easily be carried in the river current and infect salmonid fish species by penetrating their skin. Within seconds of coming into contact with the fish, the spores have entered the fish and begin their deadly life cycle.
While anglers have no control over fish eating fish or waterfowl spreading the disease through their digestive systems, anglers and others using our water bodies for recreational use can do their part by cleaning any fishing gear or other gear that comes in contact with the water. The parasite (Myxobolus cerebralis) can be transferred to other water bodies by humans after coming in contact with fishing, boating, paddling, and even swimming and waterskiing equipment. Everyone using Alberta’s water bodies, especially the river systems are being asked to thoroughly clean, drain, and dry any gear that comes in contact with a water before using it in another water body. That includes waders, boots, pontoon boats, belly boats, float tubes, and even the little things such as anglers dip-nets can’t be overlooked. Everything that comes in contact with the water must be washed.
Alberta Environment and Parks have reached out to Colorado, a state that is no stranger to the Whirling disease and has been dealing with the disease since the 1980s. Whirling Disease has been found in 13 of Colorado’s 15 major river drainages. Colorado Parks and Wildlife believe the water-borne parasitic disease originated in Europe, where native brown trout have developed a natural resistance to the parasite. However, currently there is no cure for the disease and once the parasite is established in the wild, it can live indefinitely depending on environmental conditions. However, it’s not the doom-and-gloom as it sounds. Colorado has been dealing with the disease since the 1980’s and still has an amazing trout fishery.
Leading experts say anglers need not fear handling or eating fish with Whirling Disease. The disease does not affect humans in any way. However, if you catch a fish or see a fish that you believe shows signs of Whirling disease, do not release the fish. Keep it alive and contact Alberta Environment and Parks immediately and follow their instructions.
Everyone that uses Alberta water bodies needs to do their part in preventing the spread of Whirling Disease. Our fisheries need our help from invasive aquatic species and disease throughout Canada and anglers are on the front lines to help protect our water bodies and the fish that swim within them.