2006 Proves to be a Good Year for Suckers and Water
Quality Conditions in the Upper Klamath River Basin
Reclamation
Mid-Pacific Region
Sacramento, CA
MP-06-106, October 31, 2006
Media Contact:
Jeffrey McCracken
916-978-5100
This year’s production of larval and juvenile
suckers in the Upper Klamath River Basin is the highest since
standardized sampling by Federal resource agencies began 12 years ago,
the Bureau of Reclamation and the U.S. Fish and Wildlife Service (FWS)
announce. In August 2006, the Klamath Project’s A-Canal Fish
Screen and Bypass Facility, at the southern end of Upper Klamath Lake,
returned up to 4,000 juvenile suckers per hour to the lake, a
significant increase in recruitment compared to recent years.
For example, in 2004, the rate of juvenile suckers returning was
approximately 50 per hour.
Upper Klamath Lake is the primary habitat for the shortnose and Lost
River suckers, listed as endangered species in 1988. Federal
biologists believe several factors may help explain the large increase
of suckers in 2006, including: wet winter and spring conditions;
a cooler-than-average August; and a reduced number of fathead minnows
in Upper Klamath Lake this summer, a known predator of larval suckers.
While it is uncertain precisely what conditions are necessary for good
survival of juvenile suckers into adulthood, biologists are cautiously
optimistic that 2006’s improved juvenile production numbers created
a good foundation for a measurable growth of the adult population in
the future.
“The potential benefit of this high production of suckers in the
Upper Klamath River Basin will depend on their survival to
adulthood,” said Reclamation’s Mid-Pacific Regional Director Kirk
Rodgers. “Suckers produced this year must now survive for 5-10
years to mature, spawn, and contribute to population production, but
we are very encouraged by the improved water quality conditions and
certainly by the increased numbers of juvenile fish.”
“We are hopeful this will result in an increase in adult suckers and
compensate for the low recruitment we have seen in the past several
years,” said Mr. Steve Thompson, the FWS Operations Manager for
California and Nevada. “The data from the field shows how
resilient these fish are and gives promise that they are moving closer
to recovery.”
Water quality conditions in the Upper Klamath River Basin were also
better in 2006 than in the previous 3 years. Based on
comparisons of water quality conditions recorded in the mid-northern
area of Upper Klamath Lake where most adult suckers spend the summer,
water temperatures were lower in 2006 than they had been in previous
years, while the concentration of dissolved oxygen was higher.
Annual precipitation was also 30-percent higher in 2006 than in recent
years, contributing to improved water quality conditions in the Upper
Klamath River Basin.
For further information, please contact Mr. Pablo Arroyave, Area
Manager for Reclamation’s Klamath Basin Area Office, at 541-880-2544
or e-mail parroyave@mp.usbr.gov,
or Mr. Curt Mullis, Project Leader, Klamath Falls Fish and Wildlife
Office, at 541-885-8481 or e-mail curt_mullis@fws.gov.
Additional information on Reclamation’s Klamath Project is available
online at http://www.usbr.gov/mp/kbao/.