The Hutton tui chub (Gila bicolor ssp.) is represented by a
single population that inhabits Hutton Spring on the southwest side of
Alkali Lake in Lake County, Oregon. The Hutton tui chub was listed
as threatened under the federal Endangered Species Act in 1985. In
2005, the Native Fish Investigations Project initiated Hutton tui chub
investigations to monitor 1) population abundance, 2) age composition,
and 3) habitat conditions.
The Hutton Spring tui chub is one of several morphologically diverse,
allopatric populations of tui chub that inhabit the five endorheic basins
of south-central Oregon. Hutton Spring is located on private land and
the habitat is in good condition, primarily due to conscientious long-term
land stewardship by the landowner. The habitat is currently fenced from
cattle grazing and is in stable condition. Hutton Spring has been diked
and has a pool approximately 10 meters wide, 2 meters deep and is surrounded
by rushes. A nearby spring, 3/8 Mile Spring, which also supports Hutton tui
chub, was rediscovered in 2007. Thirty years prior, Fred Bills, Oregon
State University, first noted the existence of this population of tui chub.
This spring was not located between 1977 and 2007 and the existence of this
second population was in question for several decades. The 2007 population
tui chub abundance estimate at 3/8th Mile Spring was only 87 fish (95% CI:
65-116). The 3/8 Mile Spring was small (~2 m2) with an average water depth
of 0.35 m. This spring pool was considerably smaller than when it was first
described 30 years prior. In 1977, the spring measured 3.3 meters in diameter
(~9 m2) and was ~0.7 meters deep. The spring has apparently filled in with
sediment and aquatic vegetation over the past 30 years.
The Recovery Plan for the Threatened and Rare Native Fishes of the Warner Basin
and Alkali Subbasin states that this species will probably not be delisted in the
near future because of its extremely isolated range and potential for degradation
of its habitat from localized events. The primary recovery objective for this
species is the long-term persistence through preservation of its native ecosystem.
The plan further states that the conservation and long term sustainability of this
species will be met when: 1) long-term protection to its habitat, including spring
source aquifers, spring pools and outflow channels, and surrounding lands is assured;
2) long-term habitat management guidelines are developed and implemented to ensure
the continued persistence of important habitat features and guidelines include
monitoring of current habitat and investigation for and evaluation of new spring
habitats; and 3) research into life-history, genetics, population trends, habitat
use and preference, and other important parameters is conducted to assist in further
developing or refining criteria 1) and 2), above. Actions needed to meet these
criteria include protecting and rehabilitating fish populations and habitats,
conserving genetic diversity of fish populations, ensuring adequate water supplies
are available for recovery, monitoring population and habitat conditions, and
evaluating long-term effects of climatic trends on recovery./span>
Annual Reports and
Scheerer, P. D., and
S. E. Jacobs. 2007.
Hutton Spring Tui Chub and Foskett Spring Speckled
Dace Investigations. Fish Research Project 134206M085, Annual Progress
Scheerer, P.D. and S.E. Jacobs. 2006.
Hutton Spring Tui Chub & Foskett Spring Speckled Dace Investigations.
Oregon Department of Fish and Wildlife. Fish Research Project E-2-37, Annual Progress Report,