Across the state of Alaska, salmon are returning from sea at younger ages and therefore smaller adult sizes. Alaskans have long noted these changes, which have also been observed in previous scientific studies. The Salmon Size Working Group is the first to compare trends across all of Alaska’s regions and species.


Our work

Among the findings of the Salmon Size Working Group is that the size of salmon returning to Alaska rivers is generally declining across species. However, the degree of size change varies among species—Chinook salmon are experiencing the greatest–and fastest—decline.

The plots in Figure 1 were created from more than 7.5 million measurements of salmon collected by state and federal agencies. The data are representative of fish in commercial catch and escapement projects.


Discover more about what we’ve learned

Figure 1. Trends in salmon length, 1970 – 2016

Working Group Members

Principal Investigators

Eric P. Palkovacs

Principal Investigator
University of California Santa Cruz Department of Ecology and Evolution Biology

Eric’s research focus is eco-evolutionary dynamics of aquatic ecosystems--the bi-directional interactions occurring between ecology and evolution in nature. He combines surveys of genetic, phenotypic, and ecological variation in nature with field and laboratory experiments to examine how evolution shapes populations, communities, and ecosystems and how these changes feed back to shape the trajectory of evolution.

Peter Westley

Principal Investigator
University of Alaska Fairbanks College of Fisheries and Ocean Sciences

Peter received his BSc and MSc from the University of Washington’s School of Aquatic and Fishery Sciences and his PhD from Memorial University of Newfoundland. In the summer of 2014 he made the final leg of a long journey back to his home state of Alaska, where he joined the faculty in the Department of Fisheries in the College of Fisheries and Ocean Sciences at the University of Alaska Fairbanks. As Principal Investigator of the Salmonid Evolutionary Ecology and Conservation Lab (, Peter and his students strive to understand the ecological patterns and processes that give rise to adaptation in nature, the consequences of adaptation for management and conservation, with the goal of sustaining the connections between salmon, people, and place.

Bert A. Lewis

Principal Investigator
Alaska Department of Fish & Game Division of Commercial Fisheries

Bert is the ADF&G Central Region Supervisor. His research has focused on salmon ecology including lake and stream trophic, paleolimnolgy, size and age patterns, hatchery and wild interactions, and spawning population monitoring. This research serves as a template for his commercial fisheries management responsibilities. Education: B.S. University of Colorado, M.S. Utah State University.

Team Members

Marissa L. Baskett

University of California Davis Department of Environmental Science and Policy

Stephanie M. Carlson

University of California Berkeley Environmental Science, Policy, and Management

Andrew P. Hendry

McGill University Redpath Museum and Department of Biology

Holly Kindsvter

Rutgers University

John Reynolds

Simon Fraser University

Katie Kobayashi

University of California Santa Cruz Department of Ecology and Evolution Biology

Krista Oke

University of Alaska Fairbanks College of Fisheries & Ocean Sciences

Madeline Jovanovich

University of Alaska Fairbanks College of Fisheries & Ocean Sciences

Neala Kendall

Washington Department of Fish and Wildlife

Steve Munch

NOAA Fisheries

Curry Cunningham

NOAA Alaska Fisheries Science Center

Vadim Karatayev

University of California, Davis

Rich Brenner

Alaska Department of Fish & Game, Commercial Fisheries

Gale Vick

Tanana Chiefs Conference

Other Links of Interest


How A Massive Dataset and A Set of Rural Communities Are Helping to Sustain Alaska’s Salmon: Podcast: Alaska’s Exceptional Salmon Data