Columbia/Snake migration??

Hi Guys, I have been watching the fish migration on the Columbia and Snake rivers this spring for a while now. If you havn't noticed the numbers this summer/spring have been incredible! Highest recorded numbers since 1938 or something!
However, in the last few days we have seen very high temperatures (106F in Lewiston!) and the migration especially in the Snake river has slowed dramatically. For example a few weeks ago we were over 600 fish at Lower Granite Dam and yesterday only 12 fish were counted. So the run has essentially stalled out on the Snake. Am I correct in assuming that this is mainly caused due to high water temps. in the reservoirs of course directly related to the dams?
I had a buddy tell me the other day that the fish are still moving up the rivers but they are just going through the dams at night. (I tried to call B**S** on him but I didn't have any data to back me up). He claimed that they do not monitor fish passage at night and really only monitor for an 8-hour day and extrapolate the rest of the passage counts. I always thought the fish counting was a 24 hour deal but I don't know for sure, does anyone here know for sure how the daily fish counts are tabulated?
Also, I have heard that in years like this when the runs stall out it is possible to lose thousands upon thousands of fish in the lower snake and columbia. The fish move up to certain reservoirs and then don't turn up at the next dam. Is this true, and is our great run in jepardy of becomming mediocre if it doesn't cool off soon?
Well, I appreciate any info you folks might have on this subject.

I sure hope it cools off soon!

Duke

Duke, there is a gate they open and close at start of the day and closed at the end of the day. Fish do not pass at night time. I believe that the water temp is the reason for the fish to stall. Hope it cools off or we might end up with a bunch of poached fish. Must be the killing stations that are the culprit. (DAMS) Duck In The Fog

I believe that Bonneville Dam has 24 hour counts. At night, they use a video camera to record the fish migrations and based their counts on that. It's probably easier than visual counts because they can re-wind the video to make sure their ID is accurate. The other dams don't all use video and may collect the migration data during daylight hours only.

However, your basic point about delayed migration is right on the mark. When the water temperatures get too high on the mainstem Columbia (over about 65 F), the fish stop moving. They often will pull into the tributaries where the water is cooler. Drano Lake, Deschutes River, and White Salmon River are known for their summer steelhead fishing. Many of the fish caught in the lower end of these rivers are upriver fish that have stopped to cool off. They will resume their upriver migration when the mainstem cools down. Alot of anglers know this and take advantage of it by targeting Drano and White Salmon rivers for steelhead during the warm summer months.

hay:All this brings up a good point!!! every body spends all thier time *****ing about the indians,how many fish will the whiteman kill because of high water temps behind the dams and to the best of my knoledge no one even gets the chance to eat them. just thought Id throw my two cents worth in.

Its hot out Duke but dude these fish are coming fast. Its august and people are forgetting how early these fish are. Its a total freak of nature. Goes to show what a few good water years can do. I suspect I'll be nailing a few this year in the middle of september with the fly rod. What a treat!!! Also, I think most of the damns on the columbia count fish 24 hours a day, with cameras etc.

B-run, Good to see there is still some guys from my neck of the woods still around! Yes, I know the run is really early, I just hope the temps cool off soon enough to get some more fish up here or else your september fishery won't occur until October, hehe. On a side note I have heard second hand, that a few guys have been picken' a few up on the lower clearwater already with bug rods. They are early dip-in A-runs that get the a taste of the cold water from Dworshak. Sounds like they will only be realeasing water from the dam for a couple more weeks, till then the fish will definately hang around in that area.

I'm keeping my hopes up for a banner year!!

later,

Duke