For a fish biologist, the Kootenai River system is a mesmerizing marine museum of distinct aquatic species, which also demands a unique suite of conservation and management strategies.
Notably, the Kootenai is home to the white sturgeon, the largest freshwater fish in North America, which can live to be 100 years old and weigh more than 1,000 pounds. But its dwindling populations warranted an “endangered” listing on the Endangered Species Act in 1994, and Libby Dam adds another layer of complexity to their conservation mission.
The system also provides ideal habitat for burbot, westslope cutthroat trout, bull trout, and Montana’s only native species of rainbow trout, the Columbia River interior redband trout, found solely in the northwestern corner of the state.
And until recently, it was home to longtime Fish, Wildlife and Parks fish biologist Mike Hensler, who recently transitioned into his new role as the state’s regional fisheries manager in Region 1, a position that oversees the management and preservation of 450 fishable lakes, more than 3,000 miles of fishable stream and a diverse school of native and nonnative species.
Hensler has 28 years of experience as a fisheries biologist for FWP, and since 1992 has led the management operations at FWP’s Libby office. He’s a graduate of Flathead High School, so the move back to Kalispell is a familiar one, and he’s received the American Fisheries Society Lifetime Achievement Award for his leadership in the Columbia River Basin redband trout status and recovery efforts.
“Mike has been one of FWP’s emerging leaders for a long time when it comes to both native fish conservation and recreational angling, and we are fortunate to have him step into this important leadership role,” FWP Region One Supervisor Jim Williams said.
Hensler said he’s eager to apply the diverse skillset and knowledge he’s accrued managing the Kootenai fisheries to the broader region, which is among the most challenging regions in the state to manage.
He said his experience in the Kootenai makes him well equipped for the job.
“However it happened over glacial epochs, the Kootenai has a slightly different fishery,” he said. “In much of the region the focus is on native westslope cutthroat trout and bull trout. In the Kootenai, we also have white sturgeon, burbot and our only native rainbow trout, which is the redband. It’s cool that you can say Montana has native rainbow trout, but they’re only in one place and that’s the Kootenai. That has been a pretty big focus for me. The primary focus throughout the region has been on cutthroat trout, and those efforts have been successful. But redbands have taken a back seat, so I’ve tried to bring them closer to the forefront. And I’m pretty proud of that.”
Hensler has also played a key role in assessing the effects of upstream contaminants leaching out of Canadian coalmines and into the transboundary Kootenai, as well as into Lake Koocanusa. He said a highly skilled team of researchers remains in place to continue that work, which is critical to monitor water quality and the effects of the mining toxins on fish.
“There are some huge issues in the Kootenai, and it’s just as important as other issues that the Flathead drainage faces,” he said. “Each fishery has its own unique set of circumstances, and Lake Koocanusa and the Kootenai are no exception.”
Hensler said his top priority centers on conserving aquatic and fishery resources, both for the present and future generations, particularly as development and growth in the region means more use, more pressure and additional demands on the resources.
Warming waters and illegal introductions have led to an ever-changing playing field, and striking a balance between native fish conservation and recreational angling requires juggling numerous stakeholder interests.
Illegal introductions, or bucket biology, may be the biggest issue this region faces right now, he said.
“I think there are more illegal introductions in Region One than anywhere else because of the sheer volume of water and the high number of cold water lakes with warmer water along the edges where vegetation grows,” he said. “That’s a perfect spawning area for top-level predators, and the fish that are being introduced are top-level predators. They’re able to survive and produce, so these lakes are increasingly being controlled by illegally introduced predators.”
One prominent example of how introductions can fundamentally alter an aquatic ecosystem lies in Flathead Lake, where lake trout populations exploded after the state introduced Mysis shrimp into the upper Flathead Drainage in 1968 and eventually found their way to Flathead Lake in 1981. The increase in nonnative lake trout led to the collapse of the kokanee salmon fishery and steep declines in native fish, including bull and cutthroat trout.
FWP’s management actions to reduce lake trout populations and conserve native fish species have been aggressive, but what’s good for native fish isn’t always good for the recreational angler who enjoys catching monster lakers.
Achieving symmetry in managing those competing interests on Flathead Lake will be an ongoing challenge, Hensler acknowledged.
“Lake trout are a symptom of the Mysis introduction, and if I could snap my fingers and eliminate Mysis from Flathead Lake and Whitefish Lake and Swan Lake I would do it,” Hensler said. “The reality is that isn’t going to happen. These are incredibly large systems and we have a responsibility absolutely to native species but also recreational fishing, which is still very much part of our management scheme at FWP. How we can accomplish both at some level is what I am working toward. But it’s contentious and there’s never going to be an easy answer.”
As evidence that conservation and recreation can coexist, Hensler pointed to the success of FWP’s efforts to preserve and restore the westslope cutthroat fishery in the pristine South Fork Flathead River, which meanders through a large swath of protected wilderness, the Bob Marshall Wilderness Area.
Hensler hopes to look at how those efforts could apply to other native species like the redband.
“The Flathead is the last best place for westslope cutthroat trout, and determining where we can develop projects that have a similar kind of effect for other native species that has permanency to it is the goal,” he said. “We’re going to be asking ourselves the same kinds of questions that we asked on the South Fork when we get started with redbands.”
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