Location matters in the war on lake trout

  • In Yellowstone, the Park Service employs its own boats, left, and several commercial fishing outfits to catch lake trout via gillnets in an effort to protect cutthroat trout.

    Thomas Lee
 

Lake trout aren't just found in low-elevation lakes with large recreational fisheries, like Montana's Flathead Lake. For more than two decades, they have thrived in the crystalline, icy waters of Yellowstone Lake, in the heart of Yellowstone National Park.

Biologists believe someone introduced lake trout to Yellowstone Lake back in the 1980s. Since then, the population has exploded, while the Yellowstone cutthroat trout, a beautiful, small-bodied native, has declined by more than 90 percent. Lake trout both eat and compete with cutthroat trout, as they do with bull trout in the Flathead drainage.

The loss of cutthroats has rippled through the ecosystem. Unlike lake trout, which spend their entire lives in lakes, cutthroat return to their natal streams to spawn. There, a host of animals – from spiders to bald eagles to grizzly bears – depend in some way on their carcasses for food. Scientists are finding that when those animals can't get trout, they'll turn to other things. Arthur Middleton, a biologist at Yale, recently published a paper in the journal Proceedings of the Royal Society B showing that, in the absence of cutthroat, grizzly bears have started eating more elk calves. As a result, some elk populations have declined. "That a change in the trout fishery can reach to elk migration is striking," Middleton says. "It shows how the broader effects can be felt far outside the park."

This helps explain Yellowstone's increasingly aggressive drive to eradicate lake trout. Unlike at Flathead Lake, where there is an entrenched lake trout recreational fishery and multiple managers, Yellowstone Lake is overseen solely by the National Park Service, which has a mission to preserve native species. Park biologists have had broad public support to deploy increasingly sophisticated methods, including using experienced gillnetting crews from the Great Lakes to sweep up lake trout.

In the first years, gillnetters caught 25,000 to 50,000 lake trout each summer; the catch rose to around 100,000 by the mid-2000s. As funding has increased – to over $1 million a year from both private and public sources – so, too, has fishing; gillnetters now remove between 200,000 and 300,000 lake trout per year. Although the agency has gotten some pushback from lake trout-loving fishermen, most angling groups support the effort, says Dave Hallac, division chief of the Yellowstone Center for Resources at the park.

The exact number of remaining lake trout is unknown, but Hallac guesses that it is in the hundreds of thousands, and that gillnetting will need to go on for years. But there are promising signs that the population is declining. In the last two years, gillnetters have caught fewer lake trout, and an independent monitoring program has found juvenile cutthroat trout in Yellowstone Lake for the first time in years. "It's too early to claim success just yet," Hallac says, "but we're definitely on the right track."

Return to:

The great Flathead fish fiasco
High Country News Classifieds
  • WATER RIGHTS/ADJUDICATION BUREAU CHIEF
    Job Overview: Working to support and implement the Department's mission to help ensure that Montana's land and water resources provide benefits for present and future...
  • CLIMATE CHANGE COORDINATOR
    The Greater Yellowstone Coalition is seeking a Climate Change Coordinator to play a lead role in shaping our programs to make the Greater Yellowstone Ecosystem...
  • EXECUTIVE DIRECTOR
    Executive Director Position Announcement POSITION TITLE: Executive Director ORGANIZATION: Friends of Cascade-Siskiyou National Monument REPORTING TO: Board of Directors EMPLOYMENT TYPE: Part-time - Full-time, based...
  • HEALTHY CITIES PROGRAM DIRECTOR
    The Healthy Cities Program Director leads and manages the Healthy Cities Program for the Arizona Chapter and is responsible for developing and implementing innovative, high...
  • CONSERVATION PROGRAM MANAGER
    Grand Staircase Escalante Partners (GSEP) Conservation Programs Manager Job Opening Our Mission: Honoring the past and safeguarding the future of Grand Staircase-Escalante National Monument through...
  • ASSOCIATE DIRECTOR
    Grand Staircase Escalante Partners (GSEP) Associate Director Job Posting Our Mission: Honoring the past and safeguarding the future of Grand Staircase-Escalante National Monument through science,...
  • UNIQUE, ENERGY-EFFICIENT HOME ON ACREAGE NEAR MOSCOW, IDAHO
    Custom-built energy-efficient 3000 sqft two-story 3BR home, 900 sqft 1 BR accessory cottage above 2-car garage and large shop. Large horse barn. $1,200,000. See online...
  • OUTDOOR ADVENTURE BUSINESS FOR SALE
    Missoula Outdoor Learning Adventures (MOLA) - established and profitable outdoor adventure & education business in Missoula, Montana. Summer camp, raft & climb guide, teen travel,...
  • OJO SARCO FARM/HOME
    A wonderful country setting for a farm/work 1350s.f. frame home plus 1000 studio/workshop. 5 acres w fruit trees, an irrigation well, pasture and a small...
  • STEWARDSHIP COORDINATOR
    Join Skagit Land Trust (the Trust), a not-for-profit conservation organization based in Mount Vernon, Washington, and help protect land for people and wildlife. Skagit Land...
  • 2022 SEASONAL SCIENCE EDUCATOR
    The Mount St. Helens Institute Science Educator supports our science education and rental programs including day and overnight programs for youth ages 6-18, their families...
  • POLICY DIRECTOR
    Heart of the Rockies Initiative is seeking a Policy Director to lead and define policy efforts to advance our mission to keep working lands and...
  • CHIEF FINANCIAL OFFICER
    Self-Help Enterprises seeks an experienced and strategic CFO
  • CONSERVATION SPECIALIST - LAND PROTECTION FOCUS
    View full job description and how to apply at
  • RIVER EDUCATOR & GUIDE
    River Educator & Guide River Educator & Guide (Trip Leader) Non-exempt, Seasonal Position: Full-time OR part-time (early April through October; may be flexible with start/end...
  • LAND AND WATER CONSERVATION DIRECTOR
    The Land and Water Conservation Director is a full-time salaried position with the Mountain Area Land Trust in Evergreen, CO. The successful candidate will have...
  • FOOD SYSTEMS ENVIRONMENTAL FELLOWSHIP
    If you were to design a sustainable society from the ground up, it would look nothing like the contemporary United States. But what would it...
  • EXECUTIVE DIRECTOR
    The Rio Grande Headwaters Land Trust (RiGHT) is seeking an Executive Director who will lead RiGHT toward a future of continued high conservation impact, organizational...
  • COMMUNITY ORGANIZER
    Help protect Montana's water quality, family farms and ranches, & unique quality of life. Work hard, meet good people, make the world a better place!...
  • NEW BOOK:
    True Wildlife Tales From Boy to Man. Finding my voice to save wildlife in the Apache spirit. 365+ vivid colorful pictures. Buy on Amazon/John Wachholz