Michael Milstein, Public Affairs Specialist, BPA: We’re here at Libby Dam in northwest
Montana, which is an important source of hydroelectric power. It also provides flood control. Normally
you wouldn’t see water coming over the spillway behind me, but this week in early June the
U.S. Army Corps of Engineers, in cooperation with BPA, the U.S Fish and Wildlife Service,
and states and tribes, is spilling extra water down the river in hopes of helping white sturgeon.
These are enormous, endangered, long-lived fish that haven’t spawned successfully in
a few decades. The idea behind this spill is to recreate more natural spring runoff
conditions when the river is high and lead the sturgeon to swim upriver to much more
productive spawning grounds. There are biologists out in the river checking to see whether the
fish are moving.
Pete Rust: The latest population estimates show that it was about a thousand fish.
Greg Hoffman: And it’s really tough to assign success to a population that’s so suppressed.
Sue Ireland: That’s why it’s so critical for us to spawn as many fish as we can right
now. We don’t get a do over.
Pete Rust, Fisheries Research Biologist, Idaho Department of Fish and Game: There are two
different trains of thought. Either the dam has changed their behavior so they don’t
come here anymore. Or the dam has changed conditions at where they currently spawn.
And we don’t know which is right. We don’t know anything about what these fish need for
survival. All we know is where they’re spawning now is not working.
There’s one; 559 and that’s a female we tagged this year.
Some of the adults spend a good chunk of their time in the river before they spawn and after
they spawn. And some of the fish are mostly in the lake and they only come to the river
to spawn and then they quickly go back. And then there’s in between. They’re not all
doing the same thing, which isn’t really surprising.
Nobody here.
Greg Hoffman, Fish Biologist, U.S. Army Corps of Engineers: We’ve been monitoring river
conditions and fish migration for quite a few years now. And so what the spill test
is doing is approximating a better water year in the lower river here. So we’re trying
to create a depth that was closer to pre-dam conditions with spill and the habitat work
that the [Kootenai] Tribe and others are bringing on to line.
And the other half is we’re trying to learn if our temperature management strategy at
Libby Dam is going to be effective in pairing with the flow conditions. The U.S.G.S. [Geological
Survey] has done work for almost a decade in examining the effects of flow on substrate
— how the river channel changes with flow. But what the GS did was show us through their
coring that the sediments downstream have probably always been sand, silt, clay, and
that our flows really had very little effect on that. What we’re doing now is more closely
in tune with what flows did. And that is provide depth, move substrate, provide fish spawning
migration cues — to make these fish migrate where we think they could be successful in
their spawning.
Sue Ireland, Director, Kootenai Tribe of Idaho Fish and Wildlife Department: Well, the [Kootenai]
Tribe’s been working for several decades on restoring the population with the aquaculture
program. Basically we’re creating the next generation here at the hatchery. We’ve been
able to have good survival of fish that we’ve put back out into the river. But we also realize
that there’s a need to restore the habits. And so that takes several different actions
and activities beyond flow or spill. We need to have complex habitat where you have a deepened
channel and a connected floodplain that provides those ecosystem functions that are missing
right now.
And then also, productivity is really low. Libby Dam holds back about sixty percent of
the phosphorus. And because phosphorus is a building block for all the different trophic
levels we’re adding nutrients to the system. By restoring the nutrients we provide the
food that the fish need for survival. So habitat, and food, and flow probably all kind of go
hand-in-hand.
John Siple, Manager, Kootenai Tribal Sturgeon Hatchery: This facility is actually a conservation
hatchery. What we try to do is maintain the genetics of the Kootenai white sturgeon until
they can sustain themselves.
She’s 74 kilos, which is about 160 pounds. Female sturgeon, to reproduce the first time,
it’s usually 26 to 30 years in age. And then it’s three to six [years] in between
cycles because they have so many eggs. So it’s going to be 2040 for the first female
out of this year class to even start to reproduce.
The recruitment into the wild stock is non-existent or very limited. So we’re trying to maintain
the genetics until they reproduce and recruit in numbers.
Jason Flory, Biologist, U.S. Fish and Wildlife Service: They’re still on a path towards
extinction in the wild and so each year the sense of urgency gets ratcheted up another
notch. There are a lot of resources going towards studying the species so we can streamline
recovery.
I think in the next three to five years or so we’ll look back on this and say we learned
a lot and that was really valuable data we collected and tests we ran.