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Here's another dam query A recent story about Talent Irrigation District's grass carp experiment mentioned the 1996 spill of an herbicide that killed an estimated 92,000 infant steelhead in Bear Creek. My question is how could their parents have reached Bear Creek above Medford since Bruce Babbitt and other rabid environmentalists said that Jackson Street dam was being removed last year so that fish could travel up Bear Creek to spawn, and until it was removed they could not do this? This is like removing Savage Rapids Dam so salmon and steelhead can get up river to spawn. Yet each year hundreds of fish are given away. How do they get to Cole Rivers Hatchery? -- Earl M., Medford Ask a simplistic question, Earl, get a detailed answer. You're right about one thing. Dams are not total barriers to fish passage, says Oregon Department of Fish and Wildlife district fish biologist Mike Evenson. Some fish do get upstream of Medford to spawn. It was the very young off-spring of these fish that were killed by TID's herbicide. Evenson says many more fish will make it upstream now that the dam has been removed. Depending on the conditions of the river, dam and water levels, dams can prevent or delay fish from getting upstream or downstream, causing serious problems for spawning. The removal of Jackson Street Dam will benefit fish year-round, Evenson said. But it will have the greatest benefit for the fall chinook salmon that make their way upstream in September, when water levels can be low. At Savage Rapids Dam, the opposite condition is a problem for fish passage. High water in the winter causes turbulent conditions that prevent some fish from moving upstream, said Evenson. Fish follow the current upstream. So when large volumes of water fall over the spillway as well as flow down fish ladders, fish can get confused about where to swim and never even find the ladder. If the fish are delayed too long, they can be forced to spawn downstream where the chances of successful spawning are less because of poor spawning areas, said Evenson. The fish that are given away each year are hatchery-raised coho salmon. Of the 200,000 hatchery-raised coho salmon that are released annually from Cole Rivers Hatchery, 3 to 4 percent make it back to the hatchery. Ocean conditions and food availability -- not Savage Rapids Dam -- are most likely responsible for those low return rates. (Send your questions to "Since You Asked," Mail Tribune Newsroom, P.O. Box 1108, Medford, OR 97501; or by fax to (541) 776-4376; or by e-mail to: [email protected] Please include your name, address and phone number for verification.) Mail Tribune Copyright � The Mail Tribune 1999, Medford, Oregon USA