In Southcentral Alaska, salmon declines are pinned on a toothy invader

 

Earlier this month, I wrote about the Yukon River’s chinook salmon runs, which have lately plummeted for reasons that remain murky. While researchers are years from cracking that mystery, the Yukon isn’t the only Alaskan river losing its salmon. In the state’s Susitna River basin, which courses through Southcentral Alaska near Anchorage, the mighty fish has also crashed. And unlike in the Yukon, scientists may have pinpointed the culprit: Northern pike, a rapacious invader with an appetite for young salmon.

That pike are invasive in the Susitna is a curious artifact of Alaska’s rugged geography. The fish — snaky creatures whose long jaws are spiked with needle-like teeth — are native throughout the American Midwest and Canada, and they also naturally inhabit the entirety of northern Alaska. But the Alaska Range, a 400-mile-long band of mountains that curves from Lake Clark to the Canadian Yukon, historically blocked the pike from the state’s southern reaches.

In Southcentral Alaska, invasive Northern pike can grow to more than 30 pounds. Photo courtesy of the US Geological Survey.

That changed in the 1950’s. Scientists aren’t sure how pike ended up in southern Alaska, but the most likely explanation, says Adam Sepulveda, aquatic biologist with the U.S. Geological Survey, is that an ice-fishing aficionado airlifted them by floatplane.

Although it took a few decades for the pike population to grow large enough to harm salmon returns, the nosedive, when it came, was swift. In a Susitna tributary called Alexander Creek, for instance, the number of chinook escaping to their spawning grounds plunged from nearly 4,000 fish in 1999 to less than 200 in 2010. Anglers grew despondent; once-vibrant fishing camps were boarded up. "Pike are the only species where fishermen will buy me a beer when they find out I'm working on them,” Sepulveda says.


High Country News Classifieds
  • EXECUTIVE DIRECTOR
    If you are deeply committed to public service and would like to become part of our high performing, passionate and diverse team, NCAT is looking...
  • TRIPLEX .8 ACRE KANAB, UT
    Create a base in the center of Southern Utah's Grand Circle of National Parks. Multiple residential property with three established rental units and zoning latitude...
  • FORGE & FAB SHOP
    with home on one beautiful acre in Pocatello, ID. Blackrock Forge - retiring after 43 years! Fully equipped 5,500 sf shop including office, gallery and...
  • SMALL FARM AT THE BASE OF MOUNT SHASTA
    Certified organic fruit/berry/veggie/flower farm. Home, barns, garage, separate apt, more. Just under 2 ac, edge of town. Famously pure air and water. Skiing, mountaineering, bike,...
  • FOREST STEWARDSHIP PROJECT DIRECTOR
    Become a force for nature and a healthy planet by joining the Arizona Chapter as Forest Stewardship Project Director. You will play a key role...
  • EXECUTIVE DIRECTOR
    Ranchers Stewardship Alliance is accepting applications for an Executive Director. This position will provide leadership to RSA, develop a fund raising plan, and effectively communicate...
  • WRITING PLACE: THE ANIMAS RIVER REGION WRITING WORKSHOP
    REGISTER ONLINE BY: Friday, June 15 WHERE: Durango, CO (location TBD) WHEN: Monday, July 16 Youth workshop: 10 a.m. - 12 p.m. (18 and under,...
  • EQUITY IN THE OUTDOORS COORDINATOR
    The Equity in the Outdoors Coordinator will lead community engagement, program implementation and development, and data collection for the Eagle Valley Outdoor Movement (EVOM). EVOM...
  • COMMUNITY ENGAGEMENT ASSISTANT
    The Idaho Conservation League is seeking a personable individual who is passionate about conservation to join our Sandpoint Field Office. The Community Engagement Assistant will...
  • LIGHTWEIGHT FLY ROD CASES
    4 standard or custom lengths. Rugged protection for backpacking. Affordable pricing.
  • EXPERIENTIAL EDUCATION INTERN/ASSISTANT
    Actively introduce students to Experiential Education, Outdoor Recreation, and Sustainability while engaging and challenging them to learn and participate in these diverse opportunities. Room, board,...
  • ENVIRONMENTAL INVESTIGATIVE MEDIA SERVICES
    In-depth investigations of polluters, lobbyists, regulators, elected officials and others focused on environmentally damaging projects in the U.S. and internationally. We specialize in mining projects,...
  • UNDEVELOPED 40 ACRES - SOUTHWEST COLORADO
    in beautiful Montezuma County.
  • TRUCK DRIVER
    Class A & B drivers, pass all DOT requirements and clean driving record
  • MARIA'S BOOKSHOP FOR SALE
    - Thriving Indie bookstore in the heart of Durango, Colorado. General bookstore with 34-year history as a community hub for Southwest region of CO. 1800...
  • ASSOCIATE DIRECTOR OF DEVELOPMENT
    HawkWatch International seeks an experienced fundraiser to join our awesome team! This position will provide support in all aspects of the department. We are looking...
  • DIRECTOR OF DEVELOPMENT
    will develop and execute Wild Utah Projects fundraising plan. Call, email or check full description of job online for more details:
  • HAND CRAFTED LOG HOME IN TETON VALLEY
    on ten acres. Full view of the Grand Teton. 35 miles to Yellowstone and 20 minutes to Grand Targhee Ski Area.
  • ACREAGE WITH HOME, SHOP, BARN FOR SALE!
    Must see for sng/extd fam or corp retreat in pines! $1,030,000
  • WESTERN REGIONAL MANAGER
    The American Forest Foundation seeks a smart and highly motivated candidate to join our Western conservation team. The Regional Manager supports the Regional Director to...