Higher flows, a double pulse of spring water
and a long-term habitat project in the Kootenai River resulted this year in a
20 percent increase in sturgeon moving upstream of Bonners Ferry to spawn,
according to a review last week of 2017 operations to aid white sturgeon and
bull trout downstream of Libby Dam.
An April to August water supply volume of 8.19
million acre feet, 139 percent of average, spurred river managers to initiate a
double pulse of water from Libby Dam in mid-May designed to encourage wild Kootenai
River white sturgeon to move upstream to spawn, and later to initiate a bull
trout minimum flow of 9,000 cubic feet per second downstream of the dam.
The first pulse of water for the sturgeon was
to encourage the movement and the second pulse was to trigger further movement
upstream and spawning, according to Jason Flory of the U.S. Fish and Wildlife
Overall, the goal is to provide conditions
that will enable sturgeon to migrate to, and spawn over, rocky substrates that
exist upstream of Bonners Ferry.
“The sturgeon response was what we were
looking for,” Flory said. “We saw a 20 percent response (over the previous
five-year average) in the number of tagged sturgeon migrating above Bonners
Ferry, and I think we can assume all of them were moving up to spawn.”
Flory spoke at the Technical Management Team’s
Year End Review, December 12, in Portland.
TMT is made up of fisheries and
hydro/reservoir managers from state, federal and tribal agencies. Every
December the group looks back at actions taken during spring and summer in
managing Columbia and Snake river federal hydro/fish operations. Flory’s presentation
was among nine reviewed in the day-long session. Go to http://pweb.crohms.org/tmt/agendas/2017/1212_Agenda.html to see all presentations.
Flory also gave credit to the Kootenai River
habitat restoration project near Bonners Ferry that is “mostly in place” as one
reason why the sturgeon are beginning to move and to spawn.
Still, “we will have to wait four or five
years until we know for sure if there’s been an uptick in the number of
juveniles,” Flory said.
The sturgeon pulses this year discharged 1.2
MAF from Libby Dam, which is near the towns of Libby, Montana and Bonners
Ferry, Idaho. The operation is defined in the Service’s 2006 biological opinion
for Libby operations, covering both sturgeon and bull trout, which are listed
under the federal Endangered Species Act.
The multi-year Kootenai River habitat
restoration project led by the Kootenai Tribe of Idaho focuses on the Idaho
portion of the Kootenai River, Flory said, speaking for Sue Ireland, fish and
wildlife director for the Tribe, who could not attend the Year End Review.
“The project has changed pool depths,
particularly upstream of Bonners Ferry,” Flory said. “The idea is to create big
pools upstream and move the migration of sturgeon into upstream areas for
He said the long-term project, in addition to
adding pool depth, has also added woody debris, reconnected side channels,
recreated flood plains and enhanced riparian areas.
In early May, Ireland approached TMT proposing
lower flows down to 6 kcfs in September and into the first week of November to
accommodate the habitat work near Bonners Ferry, called the Lower Meander
The Lower Meander Project will “improve
habitat conditions in the Kootenai River to help adult sturgeon migrate
upstream, improve spawning habitat, increase juvenile rearing habitat, and
improve overall ecosystem function,” she said in a Systems Operations Request.
The work included bank structures for bank
stability, but the work also helped maintain deep pools.
Workers will establish a sequence of
high-quality and deeper pools in the river to support sturgeon migration to
upstream habitats in the Braided and Canyon reaches, the SOR said.
The work began by the Tribe in 2011 and is due
to officially end in 2018. However, the Tribe could in the near future look at
more habitat work in the river.
“There are still a few planned projects in
2018 and after that there are a few downstream projects and other proposals on
the table,” Flory said.
--CBB, May 12, 2017, “River Managers To Boost
Flows From Libby Dam To Aid Kootenai River White Sturgeon Spawning,” http://www.cbbulletin.com/438899.aspx
--CBB, May 20, 2016, “Elevated Flows At Libby
Dam Aimed At Benefitting Kootenai River Sturgeon,” http://www.cbbulletin.com/436762.aspx
--CBB, December 22, 2016, “Year-End Assessment
Matches 2016 Water Supply, Stream Flow, Fish Conditions With Juvenile