fishing planet california chinook salmon

Scientists studying cod and zebrafish have shown that fishing that targets larger fish can meddle with natural selection, leading to a reduction in maximum body size in fished populations. And there could be many reasons why it’s happening. Shrinking fish has been an increasingly common phenomenon in an ocean altered by a changing climate and dominated by human activity. Chinook showed the greatest decline - on average, they declined by 8 percent - followed by coho salmon at 3.3 percent, chum at 2.4 percent, and sockeye at 2.1 percent. The extent of size reductions varied among species and regions. The study affirmed anecdotal observations. The dataset included measurements of age and length for 12.5 million individual salmon, covering four species - Chinook, coho, chum, and sockeye - across all regions of the state. In a study published in August in Nature Communications, Oke and a team of researchers analyzed 60 years’ worth of data collected by the Alaska Department of Fish and Game. “There could be really important consequences of these changes.” “You have fewer fish coming back, and each of them is smaller,” says Oke. Now, researchers have confirmed that these fish are significantly smaller as well. In recent decades, rising river temperatures in the Yukon watershed have ushered in a steady decline in Chinook abundance.

The ecological and food security implications of smaller salmon could be significant. Researchers have found that Alaskan salmon are spending fewer years at sea than they used to. Sockeye salmon migrate up a small stream in Southcentral Alaska.

This is especially true on the Yukon River, she says, where Chinook salmon is a cultural touchstone and staple food for Indigenous people in both the US and Canada. A fisheries ecologist at the University of Alaska Fairbanks, Krista Oke has heard it time and again from fishermen up and down Alaska rivers: Salmon just aren’t as big as they used to be.

Fishing planet california chinook salmon