Friday July 31, 2026
KMXT —
Peter Westley is a Fisheries Professor at the University of Alaska Fairbanks. His research explores the act of salmon straying, and whether that’s a choice or a mistake.
“If a fish does stray, it tends to end up in a stream that’s pretty close to its home stream, which sort of suggests that it’s making the choice pretty close to home,” said Westley.
He says that while straying appears to mostly be an intentional decision, there are a lot of factors at play like age, habitat changes, and even peer pressure.
“The explanation for that is sort of rooted in collective behavior and sharing of information that it essentially takes,” he said. “If the group is bigger, it takes fewer individuals that are good at navigating and orienting to be able to lead the group home”
Westley says older fish tend to stray more.
“I’m only in my mid 40s, but my memory starts to slip a little bit,” Westley said. “So the idea is that, if you’re older, you might just kind of start forgetting what home smells like.”
In addition to those memory lapses, a stream’s smell could change over the time a salmon is at sea. Some stream changes may even be significant enough that it’s no longer suitable habitat for spawning. In that case, Westley says fish will take their chances and head for new waters.