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Oregon chub, which are endemic to Oregon's Willamette Valley, were listed as "endangered" under the Endangered Species Act in 1993. In 2014, they qualified for delisting under the Act, the first fish in the United States to be recovered under the act.
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Brian Bangs (left) and Paul Scheerer (right) biologists for the Oregon Department of Fish and Wildlife, implemented the Oregon Chub Recovery Plan.
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Video interview with Oregon chub project leaders
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The Oregon chub (Oregonichthys crameri) is a small minnow found only in the Willamette River basin of western Oregon. This little speckled fish reaches a maximum length of 3 inches.
Their entire life cycle is spent in low velocity off-channel habitats such as beaver ponds, oxbows, side channels, backwater sloughs, low gradient tributaries and flooded marshes of the Willamette River and its tributaries. Oregon chub feed on tiny crustaceans, and spawn between April and September.
At one time, Oregon chub thrived throughout lowland areas of the Willamette Valley in shallow, slow moving waters. Historically, floods that created and destroyed Oregon chub habitat occurred on a regular basis in the Willamette Valley. Rivers overflowed their banks, scouring new side channels and backwater areas while filling in other areas. Of all Oregon native fish species, the Oregon chub was ideally suited to making these areas home.
Flood control altered this dynamic process. Dams were built to reduce peak flows, causing river channels to become more stationary. Dams were built to reduce peak flows, causing river channels to become more stationary. Habitat loss also resulted from dike construction, channelization of the Willamette River and its tributaries, removal of snags for river navigation, agricultural practices, and draining and filling of wetlands. Additionally, nonnative species such as bass, bluegill and mosquitofish were introduced. These species are also well suited to the habitat preferred by Oregon chub.
Oregon chub were listed as “endangered” under the federal Endangered Species Act in November 1993. To evaluate Oregon chub distribution and population sizes, the Oregon Department of Fish and Wildlife conducted surveys from 1991 through 2013. The objectives of the surveys were to collect information on the distribution and abundance of Oregon chub, the characteristics of historic Oregon chub habitats, the presence of non-native and native species in thes habitats, the characteristics of potential introduction sites, and the evaluation of Oregon chub introductions.
Currently, there are 80 locations in the Willamette river basin containing Oregon chub. The Oregon Chub Recovery Plan sets criteria for down listing this species from endangered to threatened. These criteria state that in order to down list the species there must be 10 populations of Oregon chub containing at least 500 adults, all 10 populations must be stable or increasing in abundance for five years, and these populations must be geographically distributed such that at least three populations are in the Middle fork Willamette drainage, the Santiam drainage, and the main stem Willamette drainage. Oregon chub were down listed from “endangered” to “threatened” in May 2010. To delist the species there must be 20 populations of Oregon chub containing at least 500 adults, all 20 populations must be stable or increasing in abundance for seven years, and these populations must be geographically distributed such that at least four populations are in the Middle Fork Willamette drainage, the Santiam drainage, and the main stem Willamette drainage. These criteria were met in 2012 and 2013.
A major recovery effort includes the introduction of Oregon chub into suitable introduction sites. Potential introduction sites must meet the following criteria: sites must not contain nonnative fish, must be secure from invasion by nonnative fish, must be located within the chubs’ historic range, must contain an abundance of aquatic vegetation, and cannot dry up seasonally. Off-channel sites with minimal connection to the river during flood events are preferred. Site modification is permitted to meet these criteria. To date, Oregon chub have been successfully introduced into 21 new locations.
In 2009, ODFW initiated a floodplain study to assess the impacts of U.S. Army Corp of Engineers flow management on Oregon chub populations, with a focus on identifying those conditions (temperatures and flow regimes) that may allow chub to exist in habitats that have frequent connection to rivers with the nonnative fishes that live there.
Oregon Chub Map (jpg)
ODFW Oregon Chub Research
Oregon Chub Recovery Plan (pdf)
USFWS Oregon Chub Fact Sheet
Endangered Species Act
Endangered Species Act Delisting Report
Oregon’s Listed Animal Species
Oregon chub first fish to be recovered under ESA
Oregon chub found in Molalla River basin
The comeback of Oregon chub: no longer an endangered species
Oregon chub rebounds
Oregon chub on ODFW’s Flickr Photostream |
