December 31, 2019 — Chinook salmon, also known as king salmon, are getting smaller, and a team of scientists at the University of Washington think they know why. A new study says killer whales might be behind Chinook’s declining size.
Chinook salmon are an important part of life in Southeast Alaska. Part of the prized fish’s value is its size. Chinook are the largest Pacific salmon.
But in the last two years, returns have been low. Ketchikan, Wrangell and Petersburg all saw their king salmon derbies cancelled in 2018 and 2019. And forecasts for 2020 don’t look much better.
But it’s not just their numbers that are declining.
University of Washington researcher Jan Ohlberger published a paper last year that shows Chinook are getting smaller, too. Up to 10 percent smaller.
That discovery intrigued the researcher.
“The question is, what is the cause of that?” said Ohlberger in a recent phone interview.
A causal claim is difficult to make. Correlation, of course, doesn’t always imply causation.