Cold water, diverse survival strategies may be key to Chinook salmon spawning success

A study published recently in Fish & Fisheries offers a comprehensive look at the state of North American wild Chinook salmon. 

The research team found a strong link between Chinook abundance trends and time spent in relatively cold freshwater and marine habitats. The life histories of Chinook stocks can vary widely even within the same river system. A key example of intraspecies diversity is run timing: whether a population returns to freshwater in spring, summer, or fall.

"While most populations declined, some increased in abundance," Dr. Atlas says. "Chinook populations are stable and even recovering in certain systems.

Seems pretty basic that a salmon will do better in cold, clean water than otherwise.  Hope they didn't spend too much public money coming to that conclusion.

Chinook populations also remain strong in watersheds where cold water is reliably accessible—as well as in other systems where habitat restoration, dam removal, and fish passage improvements are protecting and enhancing access to intact habitats.

An example is the relative abundance of wild spring Chinook in Butte Creek, a tributary of California's Sacramento River that has benefited from flow augmentation and extensive ecosystem restoration. In Oregon's Clackamas and Sandy Rivers, spring Chinook have also made a remarkable recovery following dam removals and other fish passage corrections.

Interesting that the Sacramento and Klamath river populations are down, but Butte Creek is up.  Seems like the lesson is clear - keep the water cold, clear and as abundant as possible.

Here's a giant dead salmon a Fish and Game guy found in the Sacramento back in 2009.  Big, Alaska sized fish!  They are out there, lurking in the deepest, darkest holes, hungry and looking for an easy bite.  No skinny dipping advised.

Thanks for sending the article, Joe!