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MetaData for 2007 Oregon Chub Investigations Progress Reports 2007
2007 Oregon Chub Investigations Progress Reports 2007
Identification Information
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Citation
- Originator: Scheerer, P.D., P.S. Kavanagh, B.L. Bangs and S. E. Jacobs
- Publish Date: 2008
- Online Link:
None
- BPA Project #:
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Contact Information
- Agency: Oregon Department of Fish and Wildlife
- Name: Cedric Cooney
- Job Position: Natural Resources Data and Systems Manager
- Telephone: 503-947-6094
- E-Mail Address: cedric.x.cooney@odfw.oregon.gov
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Description
- Abstract: Oregon chub Oregonichthys crameri, small minnows endemic to the Willamette Valley,
were federally listed as endangered under the Endangered Species Act in 1993. Factors
implicated in the decline of this species include changes in flow regimes and habitat
characteristics resulting from the construction of flood control dams, revetments, channelization,
diking, and the drainage of wetlands. The Oregon chub is further threatened by predation and
competition by non-native species such as largemouth bass Micropterus salmoides, crappies
Pomoxis sp., sunfishes Lepomis sp., bullheads Ameiurus sp., and western mosquitofish
Gambusia affinis. We continued surveys initiated in 1991 in the Willamette River drainage to
quantify the abundance of known Oregon chub populations, search for unknown populations,
evaluate potential introduction sites, and monitor introduced populations as part of the
implementation of the Oregon Chub Recovery Plan.
We sampled a total of 70 sites in 2007. New populations of Oregon chub were
discovered at Green Island in the lower McKenzie River and in the Muddy Creek drainage (Linn
County). We confirmed the continued existence of Oregon chub at 34 locations. These
included 23 naturally occurring and 11 introduced populations. We did not find Oregon chub at
nine locations where they were collected on at least one occasion between 1991-2006.
Nonnative fish were collected at most of these locations.
We obtained abundance estimates of 18 naturally occurring populations and 11
introduced populations of Oregon chub located in the Middle Fork Willamette, Santiam,
McKenzie, and Mid-Willamette drainages (Table 1). We introduced additional Oregon chub into
the South Stayton Pond in the Santiam drainage and into Cheadle and Display Ponds in the
Mid-Willamette drainage.
The Oregon Chub Recovery Plan (U.S. Fish and Wildlife Service 1998) set recovery
criteria for downlisting the species to “threatened” and for delisting the species. The criteria for
downlisting the species are: 1) establish and manage 10 populations of at least 500 adult fish,
2) all of these populations must exhibit a stable or increasing trend for five years, and 3) at least
three populations meeting criterion 1 and 2 must be located in each of the three recovery areas
(Middle Fork Willamette River, Santiam River, and Mid-Willamette River tributaries). In 2007,
there were 20 populations totaling 500 or more individuals (Table 1). Fifteen of these
populations also met the second criteria. Of the 15 populations meeting criteria 1 and 2, eight
were located in the Middle Fork Willamette drainage, four were located in the Mid-Willamette
drainage, and three were located in the Santiam drainage. In 2007, we met the downlisting
criteria.
Findings to date indicate that Oregon chub remain at risk due to the loss of suitable
habitat and the continued threats posed by the proliferation of non-native fishes, illegal water
withdrawals, accelerated sedimentation, and potential chemical spills or careless pesticide
applications. Their status has improved in recent years, resulting primarily from successful
introductions and the discovery of previously undocumented populations.
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- Purpose:
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- Time Period of Content:
- Geographic Extent: Santiam, Mid-Willamette, Middle Fork Willamette, McKenzie, and Coast Fork Willamette
- Status: Final
- Use Constraints:
- Format: PDF File
Data Quality Information
- Lineage-Source:
Data Information
- No data information was supplied.
Entity and Attribute Information
- Attributes Description:
Is a physical copy maintained for reference at Headquarters?
No
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Chub2007.pdf
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