With an ugly nickname and even uglier effects on B.C. lakes, insidious “rock snot” has hit the Kootenay Lake watershed.
Less commonly known by its cumbersome scientific name of Didymosphenia geminata - or just Didymo for short – the slippery algae has been confirmed in the Kootenay Lake watershed.
The Ministry of Forest, Lands and Natural Resource Operations (FLNRO) and the Fish & Wildlife Compensation (FWCP) are asking anglers and others who ply local waters to help stem its spread.
A habitat technician checking on the progress of Gerrard rainbow trout spawning at the outlet of Trout Lake floated over a “mat” of the stuff that was estimated at 400 square meters.
“We know that it is already in the Salmo and Columbia rivers but this is the first time we have confirmed it in the Kootenay Lake watershed on such a significant scale,” said Terry Anderson.
Native to some parts of North America, it is considered invasive here.
Didymo gathers together in gelatinous blobs or mats. Ranging from pale yellow to white, it looks like thick shag pile carpeting underwater. Washed up, it can resemble dried toilet paper.
First found in B.C. on Vancouver Island in 1989, Didymo can affect oxygen levels in fish spawning and rearing areas, according to senior fisheries biologist James Baxter. It can cause gill irritations in fish and swimmers have reported feeling itchy after swimming downstream of heavy concentrations.
It’s not believed to have an adverse affect on drinking water, except for colouration and odour.
Here’s what fishermen can do to help stop Didymo’s progress:
Avoid using felt bottoms on waders; clean all gear (waders, boats nets, etc) between water bodies, preferably with a light bleach solution; and allow the gear to dry thoroughly.
“It only takes one cell on your gear to move Didymo from one system to another so it’s imperative that we all make an effort to slow its spread,” Anderson said.
Individuals who spot large mats of Didymo are asked to report them to the Aquatic Invasive Species Coordinator at Ministry of Environment at Matthias.Herborg@gov.bc.ca.