New Knapweed: Aquatic Invasive Species in Montana

By Beacon Staff

Of the many challenges facing Montana’s lakes and streams, perhaps the most pressing but controllable is the threat posed by aquatic invasive species, or AIS. Aquatic invasives include non-native plants, mussels, pathogens and fish that threaten environmental, commercial, and recreational resources.

Montana is still free of many problematic species, but some that plague other states if established here would create a multi-million dollar burden on some of the state’s most important economic drivers, including the hydroelectric, agricultural and recreation industries.

Like many of the state’s existing invasive weeds, such as knapweed and leafy spurge, aquatic invaders are nearly impossible to eradicate once established. They can push out important native species, and cost millions in tax dollars to control. The U.S. Fish and Wildlife Service estimates that AIS already cost the nation $120 billion a year. Species Montanans should worry about most include Eurasian water milfoil, didymo (rock snot), zebra and quagga mussels, and viral hemorrhagic septicemia – a virulent disease affecting fish.

Montana can avoid new AIS calamities. But it requires vigilant recreationists, as well as anyone else who moves boats or equipment from water to water. Montanans and visitors to our state can prevent AIS spread by adopting standard practices including inspecting, cleaning and drying boats and fishing gear after leaving or entering a lake or stream. It also means stopping at mandatory boat checks along highways and at launch sites.

Montana’s departments of Fish, Wildlife and Parks, Agriculture and Natural Resources and Conservation are coordinating statewide efforts to help protect Montana’s waters. This year FWP’s boat inspection program stopped two boats with zebra mussels. Fortunately in both cases the mollusks were dead and could not contaminate waters. However, if they had been alive and not intercepted they could have triggered a major infestation in the economically important waters of Flathead and Whitefish lakes.

Montana Trout Unlimited is promoting the establishment of a statewide invasive species council comprised of representatives from state agencies, legislators, and the general public. The council would streamline coordination among AIS efforts.

The most effective means of combating AIS, however, will always result from the individual behavior of recreationists, irrigators, highway workers, firefighters and agency staff who work or play on rivers and streams.

The alternative to vigilance against AIS is the potential loss of important recreational fisheries, including valuable native species such as bull and cutthroat trout. A lackadaisical approach could also cost Montana hundreds of millions of dollars of economic activity and mitigation costs. The cost would be transferred to the public in higher utility bills.

The risk from AIS is not overblown. The first invasive mussels that came to the U.S. were in the ballast of a single transatlantic ship. The resulting cost to the economies of the Great Lakes States has been staggering. We should take preventative measures today. Without vigilance, we risk losing many of the natural birthright that drives our economy and culture.

Morgan Sparks is a UM student and former intern for Montana Trout Unlimited.