Montana Public Radio

Mussel Invasion Would Cost Montana Hundreds Of Millions, Report Says

Jan 24, 2019

If invasive zebra and quagga mussels were to infest lakes in Montana, the state could lose more than a $230 million per year in mitigation costs and lost revenue, according to a report released Thursday from the Montana Invasive Species Council.

Stephanie Hester is the council’s coordinator. She says the economic effects of a full-blown zebra or quagga mussel infestation could be considerably higher.

"The big takeaways are that this report doesn't even come close to capturing the full costs that would be associated with a maximum mussel invasion in Montana. It only estimates the cost to affected stakeholder groups, and yet that cost is $234 million per year in perpetuity."

The report, completed by researchers at the University of Montana’s Flathead Lake Biological Station, estimates potential costs to recreation, power and water infrastructure, irrigation, home values and other sectors if mussels were to infest every lake and river in Montana.

"The top three losers would be the recreation industry, agriculture in Montana — which, as you know, Montana has 2.5 million acres of irrigated land — and then infrastructure. We all know invasive mussels pose a huge risk to our hydropower infrastructure."

Hester says the report outlines a low-ball estimate and doesn’t include qualitative values like ecosystem health and sense of place.

The report also estimates lakeshore property values could drop almost $500 million due to degraded water quality and harmful algal blooms. That means local governments could lose $2 to $4 million in property taxes each year.

States with established zebra and quagga mussel infestations have spent billions of dollars dealing with their effects, notably to hydropower dams, boats and docks, irrigation systems and water utilities.

That green and brown gunk is a mix of algae, plankton and bits of genetic material that hold the answer to whether Flathead Lake has mussels in it. One sample comes from 9 meters deep, the other from the surface.
Credit Nicky Ouellet

Scientists have not found a way to kill mussel colonies in open water and eradicating clusters in pipework requires perpetual treatments.

"The reason prevention is so important is because there are no real, meaningful treatments to eradicate mussels. Once you get them and they're established adult populations, you're always looking at mitigation and lost revenue just to manage the mussels," Hester says.

Baby invasive mussels were first detected in Montana’s Tiber Reservoir in 2016, with suspect detections in Canyon Ferry. No adults have been found and juveniles haven’t been detected since.

In the wake of the first detection, the state ramped up its aquatic invasive species, or AIS, prevention and monitoring program, nearly doubling its funding in 2017.

Hester says the $6.5 million the state spends each year keeping the mussels out is a fraction of what it would cost to live with the bivalves.

"We are only spending 3 percent on prevention, and Montana compared to other western states, is spending thousands of dollars more per year on invasive mussel prevention," she says.

But funding for the AIS program sunsets this year. Legislators are considering a bill that would use a mix of boat and fishing license fees and general fund money to cover prevention and monitoring costs.

"We need to make sure we have a good, sound program, one that’s adequately funded and one that does what we intend it to do," says Representative Willis Curdy, a Democrat from Missoula.

Curdy is carrying the funding bill (HB32) on behalf of the Environmental Quality Council. Under Curdy’s bill, Montana motorized boat owners would pay $10 annually and non-motorized boaters would pay $5. Out-of-state boaters would be subject to a $60 annual fee for motorized boats. In-state fishermen would pay $2 for the AIS prevention pass, and out-of-state fishers would pay $7.50.

Tom Longendyke cleans mussels from a screen that filters water going into a treatment plant in St. Paul, Minnesota.
Credit Nicky Ouellet

Curdy says the fee structure puts more of a burden on out-of-state boaters and anglers because they pose a greater risk of carrying new invasive species into Montana.

"They have boats and they’re bringing them right back into Montana. It is a consideration, for sure."

General fund money would cover $5.3 million over two years. That’s a change. Previously, hydropower producers and electric co-op customers paid fees, along with anglers, to fund the state program. Members of the Environmental Quality Council spent the summer trying to find a way to spread out the cost of prevention more fairly.

Curdy expects his bill will change over the course of the session. But he says one way or another, legislators need to find a way to pay for AIS prevention and monitoring.

"If they come here, it’s going to be billions of dollars trying to take care of the infestation. It’s a big deal. It’s too bad we have to spend money on this program, but the reality is here and we need to pony up and get with it."

Curdy’s bill has its first hearing on February 4.

What happens if Montana fails to stop the coming invasion of zebra and quagga mussels threatening the state's water bodies? MTPR's Nicky Ouellet looks into Montana's future (or one possible future) to see how the invasive mussels changed the Great Lakes region, and examines Montana's efforts to detect and prevent their spread. Learn more now with "Subsurface" or subscribe wherever you get your podcasts.