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February 03. 2016 12:01AM Since You Asked: Getting a feel for winter vs. summer steelhead I read in your Fishing Report each week that the guys at Cole Rivers Hatchery collected such and such number of summer steelhead and 10 or so winter steelhead. They're catching them at the same time in the same pen. How are they sure they can tell the difference between a summer steelhead and a winter steelhead? — Anonymous guy from the gym   Now, before we answer your question, Anon, we just want to make it clear that we're fair game to be questioned about anything if you spy us out and about. That includes the gym, but wait until we're off the crunch table because we at Since You Asked Central lose count easily and we don't want to have to start over. That said, Cole Rivers Hatchery Manager David Pease says he and the technicians who sort Rogue River steelhead that enter the hatchery's collection pond are pretty well-schooled in telling the difference between the two. First, the winter steelhead are larger and brighter than summer steelhead captured in January or February, Pease says. Also, the condition of the fish is a clear giveaway. Early-run winter steelhead are a few months away from spawning, so they are far firmer than summer steelhead, which by now could be leaking eggs or milt when handled. "The summers are starting to degrade quite a bit, but the winters will be rock-solid," Pease says. The old squeeze test is used because there is so much overlap in the time summer and winter steelhead reach the hatchery, despite their significant difference in spawning time. It's different for the spring chinook and fall chinook captured in late-summer and fall at the hatchery, which sits on the Rogue 157 miles from the ocean. First, there are wild spring chinook and fall chinook in the Rogue. While Cole Rivers releases close to 1.7 million spring chinook smolts annually, it doesn't raise any fall chinook for release into the Rogue, but wild fall chinook do end up in the collection pen annually. Research shows that wild chinook that enter the hatchery before Sept. 1 are much more likely to be spring chinook than fall chinook, but biologists don't want to mix the genetics of spring chinook and fall chinook, so all wild spring chinook added to the brood stock much enter the hatchery before that date. Any wild chinook captured after that date are isolated in a separate pen, Pease says. Those that live to Oct. 1 are likely fall chinook and get trucked back downstream and released, he says. Those that enter the hatchery after Oct. 1 are considered fall chinook that biologists don't want released because they could spawn over spring chinook redds in the upper Rogue, so they are euthanized, Pease says.   —Send questions to “Since You Asked,” Mail Tribune Newsroom, P.O. Box 1108, Medford, OR 97501; by fax to 541-776-4376; or by email to [email protected] . To see a collection of columns, go to mailtribune.com/youasked . We’re sorry, but the volume of questions received prevents us from answering all of them. http://www.mailtribune.com/article/20160203/NEWS/160209933 © 2016 Copyright © 1995-2011 Crain Communications Inc. All Rights Reserved. Terms of Use Privacy Statement -->