Alaska’s salmon are getting smaller

New research finds some species diminished by as much as 10% and that the climate crisis may be a driving factor.

 

A pair of spawning salmon, tailed by a sneaky jack near Pasagshack, Kodiak, Alaska.

This story was originally published by the Guardian as part of their two-year series, This Land is Your Land, examining the threats facing America’s public lands, with support from the Society of Environmental Journalists, and is republished by permission.

The fishermen and women knew something was off with their catch. “At first, it was just a general comment by everybody: ‘The fish, yeah, I didn’t get any big ones this year,’ ” said Richard Burnham, who has commercially harvested salmon for four decades in the interior Alaska village of Kaltag.

Now, a new study has borne out those observations on a huge scale, documenting body size declines in fish across the entire state of Alaska in four different species of salmon: chinook, sockeye, silver and chum.

“The fish, yeah, I didn’t get any big ones this year.”

Alaska is “the last largely pristine North American salmon-producing region,” the authors write. Yet the size of the Yukon region chinooks – the largest of the four salmon species – has diminished the most, by 10% compared with those caught before 1990.

The bodies of commercially valuable sockeye shrank by 2% statewide, and silver salmon grew 3% physically smaller.

One likely factor, the authors say, is climate crisis-driven changes in the quality or availability of the fishes’ food. A second constant, albeit weak, dynamic was that all four species were smaller when they were competing with larger numbers of a fifth species of Alaska salmon, the hatchery-raised pink.

Hatcheries release 5 billion salmon across the Pacific Rim each year, and an estimated 15% of the fish in the North Pacific Ocean are pinks raised in hatcheries.

Commercial fishermen target the low-value, soft-fleshed pinks in huge numbers, though they are far less-prized as a recreational and subsistence catch, and many anglers consider them a nuisance.

Beyond calculating the degree to which salmon have shrunk, the scientists also measured the impact of that change on people and ecosystems, finding a one-quarter decrease in the number of meals supplied by each chinook salmon, and a similar decline in the amount of nutrients that spawning chinooks carry back to rivers from the ocean.

Curry Cunningham, one of the study’s co-authors and assistant professor at University of Alaska Fairbanks, said he looks through the lens of the state’s commercial fishing industry, in which he grew up participating.

“Every sockeye, on average across the state, is worth about 50 cents less,” he said. “That’s 50 cents less per fish you’re picking out of the net.”

The scientists say their paper adds to a growing body of evidence that hatchery-raised stocks, along with wild pinks, are competing with other species of salmon and could be crowding them out.

The scientists built their paper on a mountain of salmon harvest records collected over a 60-year period by the Alaska Department of Fish and Game. Their database ultimately included 12.5 million individual measurements of fish length, from the middle of the eye to the fork of the tail.

Nat Herz covers Alaska’s environment & government from Anchorage, Alaska. Email High Country News at [email protected] or submit a letter to the editor.

High Country News Classifieds
  • PART-TIME EXECUTIVE DIRECTOR
    Mitchell Museum of the American Indian Location: Evanston, IL Salary Range: $45,000 @ 24 hours per week. send resume: [email protected] www.mitchellmuseum.org
  • OUTDOOR PROGRAM - ASSISTANT DIRECTOR
    St. Lawrence University seeks to fill the position of Assistant Director in the Outdoor Program. To view the complete position description, including minimum qualifications required,...
  • PUBLIC LANDS DIRECTOR
    Job Announcement Conserve Southwest Utah is seeking a dedicated advocate for conservation and public lands Public Lands Director a "make a difference" position Conserve Southwest...
  • FOR SALE
    Yellowstone Llamas Successful Yellowstone NP concession Flexible packages
  • DIRECTOR OF DEVELOPMENT & MARKETING
    Grand Staircase Escalante Partners is seeking a full-time Director of Development & Marketing. This is a senior position responsible for the development of all marketing...
  • LEGAL DIRECTOR
    The Legal Director will work closely with the Executive Director in cultivating a renewed vision at NMELC that integrates diversity, equity, and justice. Black, Indigenous,...
  • VICE PRESIDENT, LANDSCAPE CONSERVATION
    The Vice President for Landscape Conservation leads Defenders' work to promote landscape-scale wildlife conservation, focusing on four program areas: federal public lands management; private lands...
  • NOVA SCOTIA OCEAN FRONT
    Camp or Build on 2+ acres in Guysborough. FSBO. $36,000 US firm. Laurie's phone: 585-226-2993 EST.
  • COMMUNITY FORESTER
    The Clearwater Resource Council located in Seeley Lake, Montana is seeking a full-time community forester with experience in both fuels mitigation and landscape restoration. Resumes...
  • GUNNISON BASIN ROUNDTABLE
    The Gunnison Basin Roundtable is currently accepting letters of interest for ten elected seats. Five of the elected members must have relevant experience in the...
  • PCTA TRAIL CREW TECHNICAL ADVISORS IN WASHINGTON'S NORTH CASCADES
    Seasonal Positions: June 17th to September 16th (14 weeks) - 3 positions to be filled The mission of the Pacific Crest Trail Association is to...
  • WE'RE LOOKING FOR LEADERS!
    As we celebrate 50 years of great Western journalism, High Country News is looking for a few new board members to help set a course...
  • MEMBERSHIP DIRECTOR
    Job Announcement Job Title: Membership Director Supervisor: Executive Director Salary: Up to $65,000/year DOE Benefits: Generous benefits package — health insurance, Simple IRA and unlimited...
  • UTAH PUBLIC LANDS MANAGER
    Who we are: Since 1985, the Grand Canyon Trust has been a leading voice in regional conservation on the Colorado Plateau. From protecting the Grand...
  • EXECUTIVE DIRECTOR
    Executive Director Walker Basin Conservancy Reno & Yerington, NV Background The Walker Basin Conservancy (Conservancy) leads the effort to restore and maintain Walker Lake while...
  • WIND RIVER WRITERS AND PHOTOGRAPHERS RETREAT BY THE NATIONAL BIGHORN SHEEP CENTER
    Enhance your writing or photography skills with world-class instructors in the beautiful Wind River Mountains. All skill levels welcome. Continuing education credits available.
  • EARTH CRUISER FX FOR SALE
    Overland Vehicle for travel on or off road. Fully self contained. Less than 41,000 miles. Recently fully serviced Located in Redmond, OR $215'000.
  • ENVIRONMENTAL GEOPHYSICS
    identifies suspect buried trash, tanks, drums &/or utilities and conducts custom-designed subsurface investigations that support post-damage litigation.
  • SMALL FARM AT BASE OF MOUNT SHASTA, CALIF.
    Certified organic fruit/berry/veggie/flower farm. Small home, 2 barns (one has an apartment), and more. Approx. two acres just in the City limits. Famously pure air...
  • TAOS HORNO ADVENTURES
    A Multicultural Culinary Memoir Informed by History and Horticulture. Richard and Annette Rubin. At nighthawkpress.com/titles and Amazon.