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Chinook salmon are facing unprecedented challenges as their once-thriving populations struggle to survive. A new study published in the journal Ecosphere suggests that decades of human activities, including ocean harvest, artificial propagation and reservoir construction, have not only reduced the size of these fish, but also disrupted their ability to spawn successfully.

Joe Merz, lead author of the paper and a research affiliate with the UC Davis Department of Wildlife, Fish and Conservation Biology, said Chinook salmon play a crucial role in their ecosystems, and that fisheries management and habitat changes have weakened their natural reproductive potential.

"We've got an organism that utilizes a variety of ecosystems during its life cycle," Merz said. "We tend to slice up those ecosystems and manage them separately. We, as a society, need to think more holistically about what will benefit our fish populations."

Restoring natural spawning habitats

Chinook salmon migrate from the ocean back to the freshwater streams where they were born to spawn. Females find suitable nesting sites, usually in gravel beds, for laying eggs and move the gravel with their tails to cover and protect them until they hatch.

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