I think the answer is yes, something is going on and has been getting progressively more obvious over the last several decades.
Our Chinook are smaller when they return to the river.
Are they only returning at younger ages than before?
Are the kings smaller at age when they return?
is it a combination of both factors?
In Alaska, biologists found that over a period of thirty years, for roughly 8 Chinook runs studied, the salmon were returning at a younger age (by a year) and at smaller size-per-age.
Oregon Fish Scientists have not studied, documented, or issued a statement, so far as I’m aware, regarding what’s going on here, or whether I’m right or wrong, or whether they have noticed, or whether they care.
I find this situation of concern.
Fifty and sixty pound Chinook were commonly caught most every year in many of our coastal rivers. Check out Fishing the Oregon Country by Francs Ames to see what he had to say about big Chinook in the Oregon sport fishery.
Think I’m done on this subject for the time.
A pleasant day and good luck fishing to you all.
_______________________________________
Addendum 1: A friend just emailed me to suggest that the salmon might be smaller now because we harvested the big/old fish out of the gene pool and only the little-fish genes are left these days.
I reject this possibility – I do not believe for a minute that genetic selection is the most significant factor responsible for taking away the big kings, although it might have a little to do with it.
I was responsible for the scale collection gleaned from dead Chinook measured on the spawning grounds. Our (ODFW) crews found plenty of giants on the spawning beds in all of our north coast rivers back in the 80s to know that plenty of the big/old salmon made it past the fishery.
That’s my story and I’m stickin’ to it.
JN
Fishing - and Life - With Jay 
I think so too. i was in Alaska last August and other than my first King all the rest were ‘Jacks”. It was not what I was expecting.
Thanks for posting this. We have all noticed this over the years and seems particularly stark over the last several years, especially with the springers. Environmental pressures and genetic attrition. The same also holds true for the cohos. On a related note regarding my home waters the Umpqua and Smith. The stripped bass have successully spawned in the river the last two years and we got a robust run of jack steelhead this fall. None of the locals could remember any similar events over the last two decades.
Jay,
Is there a possibility that commercial netting (size of mesh) has anything to do with it? My thought is another might be the river environments themselves – “weak flows produce weak fish”. I remember the days of seeing “fish that could actually jump a sizeable waterfall”. Just some thoughts… Have a great day.
Terry
Sent from Outlook
________________________________
I think the mechanism you refer to is more likely affecting kings where they are harvested in net fisheries (Columbia for example). I don’t think that our coastal Chinook are intercepted in gill-net fisheries, but if i’m wrong on this matter selective harvest of larger older kings could indeed be part of the problem.