Recent posts on the debate of summer or winter fish has me wanting to share some info I received from Bob Hooton of ODFW. The correspondence was in 2001, I had question relating to the Willamette falls counts. I am not able to copy the email so I'll retype it.
Re: Winter Steelhead vs. Summer Steelhead
Date: 04/05/2001 1:47:12 PM PDT
From: Bob
Hooton@DFW.STATE.OR.US (Bob Hooton)
James:
As you are likely aware, in Oregon we are blessed with steelhead returning to Oregon rivers year round. Years ago fish biologists and anglers coined the terms "winter steelhead" and "summer steelhead" to characterize the general time of year when these fish enter freshwater and are generally available to anglers. Obviously, many runs of steelhead enter before or after these peak migration times and don't fit into easy classification.
to be more technically accurate, the terms "ocean maturing" (enter fresh water relatively mature, generally winter-run) and "river maturing" (enter fresh water relatively immature and holding for months prior to spawning, generally summer-run) are more appropriate.
He then went on to write:
There are no winter steelhead in the Oregon portion of the Columbia River basin upstream of Fifteenmile Creek (enters the Columbia River at the base of The Dallas Dam), and native steelhead populations in Oregon downstream of Fifteenmile Creek are virtually all winter-run, with the exceptions of summer steelhead populations in the Hood River, Siletz, North Umpqua and Rogue. Summer steelhead in the Sandy, Clackamas, Upper Willamette (Skamania Stock from the Washougal River in Washington), Wilson and Nestucca (Siletz stock) are all introduced hatcher fish.
Where there are overlaps in run timing in the same basin, we either adminstratively declare the fish to be either winter run or summer run based on calendar date (ie fish after Nov. 1st are always called winter-run, fish after June 1st are always called summer-run [these dates vary by basin] or we saparate them out by color and body shape.
At the Willamette Falls viewing chamber in the sping when there is an overlap between both race, the summer-runs are more slender and are very bright (chromers), where as teh winter-run always have some color, are deeper bodied and females have ther vent slightly extended. If you could handle the fish the differences become obvious, and if you were to cut them open (as I did last Saturday on the summer-run and witner run I caught at Hood River) you'd find the summer runs have thick body wall and very small egg masses, where as the winer-run females hav ethin belly walls and mature egges.
Therre always a few exeption to these rules, but the system generally works will for monitoring fish runs over the long haul.
Hope this helps.
Bob Hooton
Conservation Biology Section Program Manager
This helped me....I hope it helps some of you..
Winter Steelhead vs. Summer Steelhead
Grantspastor
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