Whirling disease has been detected in Kootenay Lake.
The B.C. government has announced that three trout samples taken from the southern arm of Kootenay Lake have tested positive for the parasite that causes whirling disease in juvenile fish. Damage to the brain stem and spinal cord results in an erratic “whirling” swimming pattern.
The presence of whirling disease in Kootenay Lake underlines how vulnerable British Columbia’s lakes, rivers, and freshwater fisheries are in the face of multiple invasive threats.
“At this point no watercraft should be able to enter B.C. without confirming that it is free of invasive plants and animals, especially the parasite that causes whirling disease and invasive quagga and zebra mussels,” said BCWF Executive Director Jesse Zeman.
“Boaters must ensure that they Clean, Drain and Dry their watercraft and trailers, and make sure equipment such as fishing gear, buckets and coolers are free of invasive creatures,” he said.
A robust surveillance and mandatory disinfection program is required on our provincial and international borders, to prevent the spread of the parasite myxobolus cerebralis, which causes whirling disease in salmonids.
Sadly, B.C. lacks a fully funded defense program.
“We are disappointed that the presence of whirling disease on B.C.’s eastern border discovered late last year did not merit a stronger response from the federal government,” said Zeman. “A defense program for whirling disease can do double duty in preventing the spread of the parasite and invasive mussels. The federal government needs to step up with funding to protect British Columbia waters.”
Whirling disease can spread throughout the water and lie in the sediment for months, but it requires the presence of salmonid finfish and a specific aquatic worm to complete its life cycle. That means to break the parasite’s life cycle, every salmonid in an affected water body must be removed or killed to deprive the parasite of hosts in hopes the parasite cannot reproduce and eventually die out. This method has been tried, but to date it has not succeeded.
“It is not clear how the parasite will affect Kootenay Lake’s kokanee and trout fisheries, but the spread of this parasite shows the vulnerability of our lakes and rivers to outside threats,” said Zeman.
Learn more about Whirling Disease: