National Forest Foundation

Hitchhikers Invade: Battling Aquatic Invasive Species

Your National Forests Magazine

Published in Summer/Fall 2015 Issue
By Greg M. Peters

From thrilling whitewater to placid ponds, the waterways of our National Forests provide us with endless opportunities to ­fish, paddle and relax. And we take advantage of these opportunities. Each year, these ribbons of blue host 46 million visits for ­fishing alone and millions more for paddling and other water-based recreation.

Ironically, those who love these places the most are inadvertently imperiling them by introducing non-native organisms to popular recreational waterways. How? As boaters travel to explore new ­fishing holes, rivers and lakeside campsites, “hitchhikers” in the form of Aquatic Invasive Species or “AIS” catch a ride in boat bilges, on trailers or attached to hulls and other gear.

It’s a double-edged sword. More people recreating on our National Forests means more people invested in forest health. But as people move around the country to ­fish a new lake or paddle a new river, they become vectors for AIS. These accidental introductions wreak havoc on our nation’s waterways, especially on the streams, rivers and lakes that dot our National Forests.

Dale Bosworth, a former Forest Service Chief, specifically identi­fied invasive species, both terrestrial and aquatic, in his 2006 declaration about the four major threats facing our National Forests. Bosworth noted that, “Public lands—especially federal lands—have become the last refuge for endangered species—the last place where they can fi­nd the habitat they need to survive. If invasives take over, these imperiled animals and plants will have nowhere else to go.” By including invasive species with the three other threats: forest fuels, unmanaged recreation and loss of open space, Bosworth raised their pro­file both inside and outside of the agency

If the boats and equipment aren't properly drained and cleaned, those hitchhikers can end up in a new waterbody.

In the ten years since Bosworth’s declaration, invasive species, and AIS in particular, have remained a vexing challenge for the agency despite its laudable efforts to control them.

Boats From Everywhere

“I was totally blown away at how far people were coming,” said Steve Shelly, a botanist and invasive species expert in the Forest Service’s Region One offi­ce. Steve and I were looking at a map of Montana put out by Montana’s Fish Wildlife and Parks (FWP) agency that showed the origin of all boats that passed through the state’s water-craft inspection stations in 2014. Covered with dots from almost every state in the country, including Alaska and Hawaii, the map highlights one of the most diffi­cult AIS challenges. When these visitors travel with their boats, they can also travel with AIS. If the boats and equipment aren’t properly drained and cleaned, those hitchhikers can end up in a new waterbody. Undetected, these invaders pose huge threats to aquatic ecosystems.

Because invasive species evolved elsewhere and “invade” new places (mostly with unintentional human help), there isn’t enough existing biological resistance within the ecosystem to prevent their proliferation. Predators and other environmental limitations in the new environment can’t keep them in check. So they spread, causing a cascade of negative impacts on local ecosystems by using up resources like food and habitat that are then unavailable for native species. They also affect local economies by damaging infrastructure like docks and boat ramps, intake pipes and irrigation head gates, and they threaten sport ­sheries and other water-based recreation opportunities.

Most of the biggest offenders evolved on a completely different continent. Eurasian watermilfoil came from Europe. Quagga mussels are from Ukraine. Zebra mussels are from Russia. Introduced to America in the mid-20th century, likely through the St. Lawrence Seaway that opened up a route for transatlantic ships to travel directly to the Great Lakes, AIS have been steadily making their way around the country on commercial and pleasure craft.

Vested Interest, Complex Problem

The scope of the problem is immense, and the management of species within and across state borders is complicated. State agencies oversee species within their respective borders, meaning it’s technically up to states to deal with AIS. However, the Forest Service clearly has a vested interest in keeping National Forest System lands and waters healthy. So the agency partners with state ­fish and game departments, county governments and nonprofits to battle AIS through a wide variety of programs and partnerships.

In the Greater Yellowstone Ecosystem, a landscape that includes three states, ­five National Forests, two National Parks and other state and federally-managed lands, the partnerships take numerous forms. A history of agency collaboration helps in this area, but it still takes a concerted effort and dedicated funding to make sure all the players are coordinated. Much of that coordination is accomplished through the Greater Yellowstone Coordinating Committee (GYCC).

"By far, the bulk of our work is focused on prevention. Our eradication toolbox is much smaller for AIS than for terrestrial invasive species. It’s very expensive, difficult and often just ineffective to remove AIS once they’re established. So we really concentrate on prevention.”

Clint Sestrich, Chair of GYCC AIS Subcommittee

The AIS subcommittee recommends various projects for funding from dollars pooled by the participating agencies. Much of the funding is granted out to local groups, like the Livingston, Montana-based Invasive Species Action Network. This group received GYCC funding, along with funding from Trout Unlimited and other sources, to install wader washing stations in all of the fly-fishing shops that surround the Yellowstone region. These wash stations allow anglers to clean their gear after each ­fishing excursion and provide messaging about the importance of preventing the spread of AIS.

The subcommittee also supports other innovative programs like training agency of­cials to visit area schools and teach young people about AIS and their harmful effects. Additional support is dedicated to an effort to analyze various state-run watercraft inspection and washing stations to see where each state has gaps, to share lessons learned, and ensure that each state has the most robust program it can.

Great Lakes, Great Problems

In the Midwest, AIS are a huge problem. When the St. Lawrence Seaway opened to trans-Atlantic ship traffic in 1957, it opened the flood gates for AIS. Since that time, there have been at least 53 AIS introduced to the Great Lakes via shipping, including two of the most damaging species: quagga and zebra mussels. These two small, seemingly innocuous mussels have caused billions of dollars in damage to power plants, municipal water systems, docks, recreation facilities, marinas and more.

“We have worked with the Shedd Aquarium in Chicago to build a display that tells people about AIS and also lists things they can do to be part of the solution,” explained John Rothlisberger, aquatic ecologist and AIS specialist for the Forest Service in Milwaukee. This collaboration is part of the Forest Service’s broad public education efforts that also included working with Discovery World, a science and technology center in Milwaukee to develop a similar display.

Zebra mussels line the shore of Lake Michigan in Wisconsin.

“We also partner with Wildlife Forever, a nonprofi­t associated with the North American Media Group, to develop billboards and PSAs, insert snippets into popular angling shows and other efforts to get the word out to the public about these threats,” he explained. “In the Great Lakes area alone, we’ve achieved more than one billion impressions through these partnerships.” These efforts are augmented by agency support of watercraft inspection and washing stations as well.

Fighting Fire With AIS-Free Water

One area where the Forest Service does have more control over the spread of AIS is wildland firefighting. While the idea of dealing with AIS in fi­ghting forest ­res may seem odd, it’s a critical issue for the agency. Cynthia Tait, a Utah-based AIS coordinator with the Forest Service, is spearheading an interagency effort to prevent the spread of AIS during wildland ­fire­fighting efforts. While this may seem like an easy challenge to solve, it’s actually pretty complicated.

First, wildland fi­res are just that, wild. No ­re hydrants offer clean water sources for ­fire­fighters to use. Instead, they pull water from local water bodies that may harbor AIS. This means firefi­ghters need quick access to maps that detail where AIS populations exist, so they can do their best to avoid pulling water from those sources. Tait’s team has developed GIS maps that provide this information to the folks in the ­field.

While the idea of dealing with AIS in fighting forest fires may seem odd, it's a critical issue for the agency.

Second, the Forest Service moves equipment around the country to respond to ­res when and where they happen, which means trucks, dip buckets and other ­fire­fighting equipment used in Florida might end up in California. In order to prevent the spread of AIS from one state to another, this equipment needs to be cleaned.

This too is no small task, as the cleaning often happens in the ­field, meaning protocols need to be efficient, effective and available to the fi­refi­ghters working in remote terrain. Massive 500-gallon ­re engines are especially hard to clean, and Tait’s team is working to develop methods that adequately decontaminate these machines with hot water as opposed to caustic pesticides. “We’ve learned that we need to circulate 140 degree water through the tanks for at least ten minutes to achieve decontamination,” Tait explained. “We’re investigating ways to do that in the fi­eld that work for the ­firefi­ghters.” All of these tactics are being included in a guidebook Tait is developing for ­firefi­ghters to use in the ­field.

Just like in other parts of the country, Tait also works with state agencies in Wyoming, Utah and Idaho to control AIS. These partnerships help keep National Forest lakes, rivers and streams free of AIS.


Early indications suggest the Forest Service’s hard work is paying off. A Montana FWP report on watercraft inspection stations showed that 40 boats entering the state’s waterways, many of which are on National Forest lands, had AIS hitchhikers. Fortunately, there were no recorded infestations of AIS in the state during 2014, showing that the watercraft inspection stations seem to be working. But AIS mitigation efforts can have real rami­fications for the millions of boaters who use National Forest waterways. John Rothlisberger, the AIS expert from Milwaukee, recounted an example on the Ottawa National Forest in Michigan’s Upper Peninsula that highlights these real-world impacts:

“We have a lake that’s half in the Sylvania Wilderness and half out. For years it was the only lake in the Wilderness that allowed motorized craft, and it was the only lake in that Wilderness Area where we detected a Eurasian watermilfoil infestation. A rapid response allowed us to control the infestation before it spread to other lakes in the Wilderness, many of which are interconnected through streams. But the District Ranger eventually had to make the tough decision to close the boat launch to motorized boats, which are generally more prone than canoes or kayaks to harbor and introduce AIS. Many folks were disappointed, while others felt that it should have been closed to motor boats much sooner.”

Challenges like these make this work both dif­ficult and rewarding. Closing a popular site or requiring people to stop and have their boats inspected can be frustrating, but it’s necessary. Even though they may be tiny, AIS are a real and signi­ficant threat to our public waterways. Fortunately, strong collaborative efforts around the country and innovative public education programs are proving that the challenge can be met.

Like this article? For a $25 donation, you’ll get two issues of Your National Forests delivered right to your door.

Share this article

More Articles

Rural Alaska Youth on the Rise: The Angoon Youth Conservation Corps Program

Read Post

Restoring Resilience to the Tahoe Region: NFF Drives Diverse Projects

Read Post

Hut to Hut Across the Country

Read Post