Climate change, hatchery competition spur developmental changes in Bristol Bay sockeye

KTUU –

Climate change is shifting the life cycle of sockeye salmon in Bristol Bay to spend less time in freshwater and more time at sea, and creating more competition between the wild stock and hatchery releases, according to new research by the University of Washington.

Since the University of Washington began collecting data on the watershed in the 1940s, winter ice on the Wood River system lakes in Western Bristol Bay are breaking up an average of two weeks earlier and the summer water temperature is several degrees warmer.

Those changes are good news for juvenile salmon because they lead to longer and more productive growing seasons both smolt and the microscopic organisms they feed on, according to the study.

“Of course the big concern is how much more warming these systems can tolerate,” said Daniel Schindler, professor of Aquatic and Fisheries Sciences at the University of Washington. “Given these last few years of really extreme hot temperatures in Alaska, we have yet to see the system tip over to the other side where they’ve become too warn for salmon. That’s somewhere on the horizon presumably, but we haven’t seen it yet.”

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