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MetaData for 2009 Borax Lake Chub Investigations Progress Reports 2009
2009 Borax Lake Chub Investigations Progress Reports 2009
Identification Information
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Citation
- Originator: Scheerer, P. and S. Jacobs
- Publish Date: 2010
- 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: The Borax Lake chub (Gila boraxobius) is a small minnow endemic to Borax
Lake and adjacent wetlands in the Alvord Basin in Harney County, Oregon (Williams and
Bond 1980). Borax Lake chub are represented by a single population that inhabits a 4.1
hectare geothermally-heated alkaline lake. Borax Lake is a natural lake perched 10
meters above the desert floor on sinter deposits, which is fed almost exclusively by
thermal groundwater. The Borax Lake chub was listed as endangered under the federal
Endangered Species Act in 1982 (U.S. Fish and Wildlife Service 1982).
Population abundance estimates obtained since 1991 indicate a fluctuating
population ranging between approximately 4,000 and 34,000 fish (Salzer 1997; Scheerer
and Jacobs 2008). The basis for the Borax Lake chub’s listed status was not population
size, but the security of a very limited, unique, isolated, and vulnerable habitat. Because
Borax Lake is situated above salt deposits on the desert floor, alteration of the salt crust
shoreline could reduce lake levels and the habitat quantity and quality available to Borax
Lake chub. At the time of the listing, Borax Lake was threatened by habitat alteration
caused by geothermal energy development and alteration of the lake shore crust to
provide irrigation to surrounding pasture lands. The Borax Lake chub federal recovery
plan, completed in 1987, advocated protection of the lake ecosystem through the
acquisition of key private lands, protection of groundwater and surface waters, controls
on access, and the removal of livestock grazing (U.S. Fish and Wildlife Service 1987).
Recovery measures implemented since listing have improved the conservation
status of Borax Lake chub and protection of its habitat (Williams and Macdonald 2003).
When the species was listed, critical habitat was designated on 259 hectares of land
surrounding the lake, including 129 hectares of public lands and two 65-hectare parcels
of private land. In 1983, the U.S. Bureau of Land Management designated the public
land as an Area of Critical Environmental Concern. The Nature Conservancy began
leasing the private lands in 1983 and purchased them in 1993, bringing the entire critical
habitat into public or conservation ownership. The Nature Conservancy ended water
diversion from the lake for irrigation and livestock grazing within the critical habitat.
Passage of the Steens Mountain Cooperative Management and Protection Act of 2000
removed the public BLM lands from mineral and geothermal development within a
majority of the basin. These actions, combined with detailed studies of the chub and
their habitat, have added substantially to our knowledge of the Borax Lake ecosystem
(Scoppettone et al. 1995, Salzer 1992, Perkins et al. 1996). However, three primary
threats remain. These include the threat to the fragile lake shoreline, wetlands, and soils
from a recent increase in recreational use around the lake (particularly off-road vehicle
usage), the threat of introduction of nonnative species, and potential negative impacts to
the aquifer from geothermal groundwater withdrawal if groundwater pumping were to
occur on private lands outside the protected areas (Williams and Macdonald 2003).
A review of the conservation status of the Borax Lake chub by Williams and
Macdonald (2003) cited the lack of recent and ongoing population and ecosystem
monitoring as one argument against downlisting or delisting the species at that time.
Although an increase in abundance is not a goal in the successful recovery of this
species, monitoring trends in abundance over time is an important management tool to
assess species status.
The objectives of this study were to: 1) obtain a mark-recapture population
estimate of Borax Lake chub and 2) to evaluate habitat conditions at Borax Lake,
including the condition of the fragile lake shoreline and outflows. This report describes
results from monitoring conducted by Oregon Department of Fish and Wildlife’s Native
Fish Investigations Project in 2009.
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- Purpose:
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- Time Period of Content:
- Geographic Extent: Borax Lake
- 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
Files
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Borax Report 2009.pdf
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