This week the U.S. Forest Service is adding 25 dump-truck loads worth of gravel, as well as several large trees with attached rootwads, to the Applegate River to improve habitat for several species of fish.
Gravel is indispensable raw material for salmon and steelhead to spawn. The nests — redds — in which salmon lay their eggs need an adequate supply of gravel the size of a plum. Dams such as those on the Applegate River block the natural flow of gravel.
"Most river systems, generally speaking, are not spawning limited, unless they have a high head dam or unless they've been splash dammed or unless they're so incised that they're cut off from their sediment supply somehow," says Ian Reid, a fisheries biologist for the Rogue-Siskiyou National Forest who is managing the project. "The chinook in some sections of the Applegate spawn on top of each other."
Adding gravel back to the river is intended to avoid this overcrowding, where one fall chinook salmon will raid the redd of another in search of scarce gravel.
Excavator operators from Blue Ridge Timber Cutting are spreading the gravel at three sites on the Applegate River: one mile below Applegate Dam, at Flumet Flat Campground and next to Star Ranger Station.
And because fall chinook are expected to begin spawning in a month, says Forest Service District Ranger Donna Mickelson, "We expect these enhanced spawning beds will be utilized almost immediately by native fishes."
Steelhead and threatened coho salmon will also benefit from the addition of gravel, but this project will help them in other ways. Unlike chinook salmon, which swim back to the ocean months after spawning, steelhead and coho young are reared near their spawning beds for 11/2 years or more before returning to salt water. They need cool water year round and hiding places from summer predators.
Coho prefer to rear in side channels, like the one near Flumet Flat, where Reid is placing trees that are more than 50 feet long and with attached rootwads.
"To create winter habitat, we will dig out three pools, each one three feet deep, and place the rootwads in them," Reid explains.
To prevent harm to coho salmon in the project zones, Reid used an electro-shocker to capture fish so they wouldn't be hurt by the excavator.
"We salvaged almost 100 juvenile coho out of this side channel this morning," says Reid. "And also five lamprey and a few steelhead. So we know they're here now."
The project was funded primarily through a grant from Title 2 of the Secure Rural Schools and Community Self Determination Act, a federal law providing funding to many western rural counties in lieu of timber payments.
The Applegate gravel supplementation project is the second of its kind in the Rogue basin. A two-year effort to add gravel to Big Butte Creek above Eagle Point concluded earlier this summer.
That project was intended to boost the population of spring chinook salmon.
"Spring chinook are significant in Big Butte Creek, because it's the only tributary to the Rogue where they spawn, although they do spawn in the mainstem," says Jay Doino, a fisheries biologist for the Oregon Department of Fish & Wildlife, who designed that project.
Though there's no dam there to block gravel flow, says Doino, but "for some reason there's no movement of spawning gravel on Big Butte Creek. In 2010, I built logjams there (to enhance habitat), but after two years they hadn't accumulated any gravel. Anecdotally, we have reports going back to the '60s that referenced spawning at sites where we have none today. What's changed, we don't know."
That prompted ODFW to try adding gravel to Big Butte Creek. For most restoration projects, Doino has had to wait years and spend hours monitoring his projects to gauge the success.
"The neat thing is that last August when we did the project, several weeks later the spring chinook were already spawning there," says Doino. "Nearly instant results. It was pretty gratifying."
Daniel Newberry is a freelance writer living in the Applegate Valley. Email him at firstname.lastname@example.org
Correction: A typographical error in the headline has been fixed.