Kootenai White Sturgeon Hatchery gets $657,800 Upgrade
To shore up hatchery water supply system
December 21, 2006
The Northwest Power and Conservation Council last week approved a $657,800 within-year budget request to shore up a Kootenai white sturgeon hatchery water supply system that was overtaxed this year by high flows.
Two 2006 events this year this year swamped the hatchery's water quality system, forcing action ahead of planned expansion of the facility.
A new biological opinion on the protected sturgeon stock called for the implementation of spring pulses of water to be released from Libby Dam in hopes it would trigger sturgeon movement to better spawning areas. The flows implemented pushed the river to flood stage, clogging the hatchery's filtration with increased sediment and causing water temperature fluctuations.
Then, in November, record rainfall against pushed the river up. Again hatchery managers had to bypass the clogged filtration system.
The first incident forced the delay of spawning by two weeks for ready broodstock. Had eggs been incubating, they likely would have been suffocated by the turbid water, managers say.
The November crisis resulted in higher than normal mortality for 5-month-old fish, the 2006 year class that will be released into the river as yearlings.
Temperature fluctuations, brought about by changing Libby Dam operations, threaten production and spawning success by altering rates and completion of maturation and reproductive timing of wild female brookstock, according to a letter of support for the funding from Bill Maslen, director of the Bonneville Power Administration's Fish and Wildlife Department. BPA funds the NPCC's Columbia River Basin fish and wildlife program.
The hatchery program was initiated by the Kootenai Tribe of Idaho in 1989 at Bonners Ferry, Idaho, to help preserve a flagging sturgeon population. The stock was listed in under the Endangered Species Act. The sturgeon population has shrunk from more than 7,000 fish in the 1970s to fewer than 600 wild fish with very little natural recruitment in the spawning population.
Much of the population decline is attributed to dam operations, which alter the environment of the large fish. The U.S. Fish and Wildlife BiOp describes operations and other measures designed to improve conditions for sturgeon.
The hatchery program artificially spawns wild brook stock and rears juveniles for release into the river.
"As the abundance of remnant wild broodstock continues to decline in the river due to natural recruitment failure and natural mortality, fewer broodstock become available for the program and to found the future population," Maslen wrote. That means the genetic diversity is shrinking through time as is potentially the fitness of the fish as the hatchery tries to rebuild the stock.
"Therefore, for reduced sediment loading in the hatchery water, precise water temperature control during the pre-spawning and spawning periods is a necessary upgrade to avoid losing or compromising future year class production for endangered Kootenai sturgeon," Maslen said.
The major components of the water quality upgrade are a filtration and settling tank system that is estimated to cost $380,256 and temperature control, $173,160, to control spikes that can affect sturgeon spawning and increase mortality in summer. A UV treatment system will also be installed to improve water disinfection at an estimated cost of $104, 384.
The goal is to have the new system completed by April.
Story courtesy The Columbia Basin Bulletin, Fish & Wildlife News, 12/21/06, http://cbbulletin.com/Free/196586.aspx
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