Monday, August 16, 2010

The Oregon Chub - A Little Fish on the Road to Recovery

The Oregon chub is a small minnow found only in the Willamette River basin in western Oregon. Adults are typically less than 3.5 inches in length. They live in habitats such as beaver ponds, side channels, and flooded marshes, with little or no water flow, silty bottoms, and aquatic vegetation for cover for hiding and spawning. Historically the Willamette River had many side channels, oxbows, and overflow ponds that provided ample habitat for the chub. Periodic flooding of the Willamette also created new habitat and transported the chub into these areas to create new, or help sustain existing populations.

There are many reasons for the severe decline of Oregon chub populations. Construction of dams and flood control projects changed the Willamette River significantly, preventing the formation of new habitats and the natural dispersal of the species. Other factors responsible for the chub’s decline include: habitat alteration such as channelization and bank hardening, the introduction of non-native fish and amphibians, herbicide and pesticide runoff from farms and roadways, and diversions.

The Oregon chub was first listed as endangered in 1993. In 1998, the U.S. Fish and Wildlife Service published a recovery plan for the chub. The goal of the plan was to reverse the decline of the Oregon chub by protecting existing wild populations, re-introducing chub into suitable habitat throughout its historical range, and increasing public awareness and involvement. The criteria set forth in the plan for downlisting the species to “threatened” was to establish and manage 10 population of at least 500 adult fish. All of these populations had to exhibit a stable or increasing trend for 5 years as well.

Along with the efforts of other agencies, active programs have been put in place to protect Oregon chub habitat. Critical habitat was designated in March of this year. The species’ status has improved recently. On April 23, 2010, the U.S. Fish and Wildlife Service changed the Endangered Species Act classification of the Oregon chub from endangered to threatened.

To learn more about critical habitat, visit

To learn more about the Endangered Species Act, visit

Submitted by Donna Allard.

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