Officials say a tiny, unsung fish that lives only in Oregon’s Willamette Valley is the first endangered fish in the U.S. to be recovered.
The U.S. Fish and Wildlife Service announced Tuesday its petition to remove Oregon chub from the Endangered Species List and touting the success story of a minnow that’s no more than three inches long.
Other fish have made it off the endangered species list -– but not because their numbers rebounded. In many cases, it was because they went extinct.
Oregon chub are a different story. Their numbers have grown from less than a thousand when they were listed as endangered in 1993 to 160,000 today. In the last 20 years, the known chub populations dotting the Willamette Valley has grown from eight to 80.
Little Fish, Big Comeback
It was a combination of invasive predators and a loss of habitat in the Willamette Valley that pushed Oregon chub to the brink of extinction, according to biologists.
An ODFW map showing natural and introduced Oregon chub.
Reintroducing the fish into predator-free ponds and allowing more water into marshlands have helped to bring them back.
By 2010, Oregon chub were upgraded from “endangered” to the less dire “threatened” status. But as of last year, the species has met all of its recovery goals. They’ve now been successfully introduced into 21 new habitats in the Willamette Valley.
“Oregon chub are so clearly recovered now,” says Paul Henson, state supervisor for the U.S. Fish and Wildlife Service in Oregon. “I have not heard of anyone disagreeing with the decision here. I’d say it’s pretty much a consensus that the time is right.”
Tracking Tiny Fish
Paul Scheerer and Brian Bangs of the Oregon Department of Fish and Wildlife have waded into Willamette Valley muck to look for chub. They sampled a thousand habitats for the easily overlooked fish to document the extent of their habitat.
Paul Scheerer and Brian Bangs. Credit: ODFW
“It’s a little bit of a needle in a haystack,” Scheerer says. “You’re looking for a 3-inch fish in what could be a 90-meter-wide channel or slough.”
Sampling for the fish is essential to de-listing the species, Bangs says, but it’s also a good way to get stuck in the mud.
“Chub like silty, muddy substrates,” he says. “The kind of places where you say I’m not drinking that water. I was stuck up to my waist in oatmeal-consistency mud for at least 40 minutes one time – just wiggling back and forth trying to work myself out.”
Their efforts revealed chub occupying new and expanded habitats and even moving upstream from one habitat to another.
‘Chub In A Tub’
Most people don’t know about Oregon chub. They’re certainly not a fish anglers try to catch -– though sport fish were part of the problem: Game fish such as bass, bluegill, crappie, and bullhead trout were brought in from other places so people could catch them. These same fish became predators of the chub.
Karen Finley added a chub pond on her farm near Corvallis.
Biologists came up with a simple plan to keep invasive fish from eating the minnows to the point of extinction: They introduced chub to predator-free ponds, where their numbers could grow.
Joe Moll, executive director of the McKenzie River Trust, calls these habitats “chub in a tub.”
“It’s a recognition that one of the threats chub face are non-native predators that do well here,” he says.
While many private landowners have tapped federal incentive programs to convert smaller acreage to chub ponds to help recover the species, Moll’s organization is working to recreate marshy chub habitat on a larger scale. On more than a thousand acres of its Green Island property, the land trust is replacing invasive plant species with native ones and planning to breach dikes that have prevented flooding near the confluence of the McKenzie and Willamette rivers.
“We’re designing projects to allow the river to come in and sort of do the landscaping for us,” he says. “Ultimately, we want to set it up so the river can essentially come in here and have at it.”
Bringing Back The Swamp
Oregon chub surveyors in the North Santiam. Credit: Laura Tesler.
Another problem that has plagued chub is the loss of ponds and sloughs. Bangs says the construction of dikes and dams to control flooding eliminated a lot of the marshlands chub like to call home.
Chub might not look like much, Bangs says, but they represent a lot of the swampy habitat that used to exist in the Willamette Valley. Often, that habitat was created when rivers shifted course and left side channels and sloughs behind.
Efforts by the U.S. Army Corps of Engineers to improve water flows through dams for salmon and steelhead habitat have also helped the lesser-known chub, Henson says.
“The chub is dependent on natural disturbances in the Willamette Valley,” he says. “That means flooding, and things that occur when you have beaver activity and wetland formation. A lot of these processes have been disrupted through human activities – agriculture, damming rivers, flood prevention. We had to figure out a way to mimic those processes and create habitats that provided those kinds of conditions for the chub.”
John Auer was surprised to find chub on his family farm.
A large chunk of new chub habitat – about 40 percent – is on private land.
John Auer, whose family owns a 900-acre farm near Monmouth, was surprised to find out that the 30-acre wetland on his property was home to dozens of Oregon chub.
Auer had teamed up with the U.S. Fish and Wildlife Service to expand the marshlands around Jont Creek, removing soil and replacing some invasive reed canary grass with native plants. But Auer says the idea was improve habitat for salmon, steelhead and waterfowl. He didn’t even know Oregon chub existed until Bangs found the fish in a pool above a beaver dam on his land.
“He told me they were a threatened species,” Auer says. “I was taken aback. I had no idea they would be here or that there even was that kind of fish.”
A thriving population of Oregon chub isn’t just good news for the future of these minnows. It’s also one more step in making the Willamette Valley a healthier place for the native birds, reptiles and other fish that live in the same swamps - and rely on the Oregon chub as part of their food chain.
Scheerer says he hopes the lessons learned from chub recovery could help recover other species, too.
“I think it’s a demonstration that it can be done,” he says. “We have a little fish that most people didn’t know about, few people care about, and we’ve managed to recover them in a working landscape.”