CFM,

I don't have any personal experience with a fall chinook project. My understanding is that spring chinook, like sockeye smolts, are super-sensitive. I cannot account for any difference that might exist between relative sensitivity between spring and fall chinook smolts. I hear that fall chinook smolts are handled in large numbers at the juvenile fish sampling facilities at McNary Dam during June and July when the water temperatures are really on the rise. There probably are mortality estimates for the sampling work that occurs there, but I'm not familiar with any.

If you're interested in the potential effects of chinook handling on the Cowlitz, I'm most concerned about those chinook that migrate through Cowlitz Falls during July and August. The historical data indicate that migrations through that area were during the spring and fall, when temperatures would have less adverse effect. We'll have to see if the off-spring of natural chinook spawners exhibit a better migration timing. I'm expecting that they will.

Sincerely,

Salmo g.