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Sturgeon responding to restoration efforts |
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January 4, 2018 |
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Re-published with permission from the
Columbia Basin Bulletin
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 month
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 Service.
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 last month 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.
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. 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 spawning.”
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 six kcfs in September and
into the first week of November to accommodate
the habitat work near Bonners Ferry, called the
Lower Meander Project.
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. |
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