Mussel prevention war grinds on in the Okanagan

The Okanagan Basin Water Board is hoping for the best but preparing for the worst in its ongoing battle against invasive mussels making their way into the big lake.

The board will launch its 10th annual Don’t Move A Mussel campaign in the spring, encouraging residents – especially those returning with watercraft from other jurisdictions, or planning to purchase used watercraft from invasive mussel-infested regions – to contact the province’s Invasive Mussel Defence program regarding an inspection, said communications director Corrine Jackson.

At their first meeting of 2023, board members learned that resources for invasive mussel vulnerability (a toolkit) is in development by Renata Claudi, an environmental scientist, from Ontario-based RNT Consultants. “We will also be looking to reach visitors coming to the Okanagan with watercraft,” Jackson said.

“Our intention is to have the toolkit ready at the same time. Over the years, we have worked closely with the province and many others to help prevent the introduction of these mussels into B.C. waters and are looking forward to providing local governments and utilities with a toolkit to deal with them, as best as possible, if they end up here.”

“If invasive mussels should get into the Okanagan, this toolkit will help local water utilities, fisheries, farmers, whoever has inwater infrastructure to understand what the risks to their facility are and also to look at ways that they can mitigate or prepare in advance to mitigate potential damage and increased operating costs,” said OBWB deputy administrator James Littley.

There could be several ways to mitigate the impact, depending on what the facility looks like, he added.

“Just as a fairly simple example, let’s say you have a water intake in a chlorinated water delivery system right now. Currently, what would typically happen is you’d have this long water intake pipe into the lake with maybe a primary filter on the end of it. But the chlorination and all of the treatment would happen in the facility.”

Changing that would require a new approach, Littley said.

“One of the potential things you could do is move the chlorination point – or at least an initial chlorination point – out to the intake so that as water goes in, it’s instantly chlorinated and that would kill any larvae before they would enter into the whole system. That’s just one example.”

However, it would not come cheap. Larratt Aquatic estimated outfitting one intake could cost at least $25,000, depending on whether chlorine is already present at the pump house, plus the cost of chlorine. Currently more than two-third of intakes in Okanagan lakes do not use chlorine.

Another alternative could be twinning those intakes so one can be shut down for cleaning, said Littley. Another might be using different types of materials such as titanium that mussels can’t attach to. “So there are a number of potential options just to prepare your system, and really control how and where you have to interact with the mussels,” said Littley.

According to the Invasive Species of B.C. website, both species have been found as deep as 110 metres but zebra mussels prefer depths of two to 12 metres while quagga mussels prefer depths of 10 to 13 metres. The City of Kelowna’s intake at the Poplar Point Pump Station, for example, is in 29 metres of water in Okanagan Lake.

The toolkit will include a section on mussel biology, said Littley. “It will tell facility managers exactly where they have to be concerned. But even if the mussels wouldn’t attach to that intake at 90 feet deep, the larvae could potentially still get in there because they are just microscopic and they float around in the water,” he added. “So you could be sucking them in even when they’re not adults. And then, once they get into the facility, they start to form shells and attach inside the pipes.”

He anticipates the toolkit will be ready for distribution this year, coinciding with the start of the annual Don’t Move A Mussel