[♪ and rushing water]
[descending drums to chime]
[♪]
Brian Ellrott: Winter-run Chinook salmon
occur nowhere else in the world
than in the Sacramento River system.
They're the only Chinook salmon species
that migrates upstream as adults during the wintertime,
and then spawns in the summertime
when air temperatures are at their hottest.
Narrator: Salmon eggs don't hatch
when water gets too warm.
Snow melt and cold-water springs feed
high elevation tributaries, like the McCloud River,
and this year-round water supply lures winter-run Chinook
more than 300 miles upstream from San Francisco Bay.
Noah Oppenheim: Salmon are a critical part of
coastal economies and coastal communities,
and the Central Valley is the engine of
salmon production on the California coast.
Brian Ellrott: For winter-run,
there were four independent populations;
the headwaters of the Sacramento River,
the McCloud River, the Pit River,
and Battle Creek.
Jon Ambrose: Winter-run Chinook were blocked
from all of their historical spawning and rearing habitat
by the construction of Shasta Dam
and hydroelectric development in Battle Creek.
There was no fish passage provided.
So, they lost access to hundreds of miles
of high-quality habitat.
Brian Ellrott: And then starting in the 1960s,
water diversions became more important.
And we get to the 1980s, about 50 percent of the water
in the Sacramento River system and the delta was being removed.
We had just a few hundred winter-run left.
[♪]
Narrator: By 1994, Sacramento River winter-run Chinook
was listed as endangered under the Endangered Species Act.
The population has remained low ever since,
supplemented with releases of young fish
from the Livingston Stone Conservation Fish Hatchery.
Rachel Johnson: Winter-run are not doing very well today
because they are relegated to one spawning population
downstream of Keswick Dam.
And they rely on the cold water that
gets doled out to them from Shasta Dam.
That cold water is the only thing that's
kind of keeping them on life support,
but it also can run out.
[♪]
Narrator: During the recent extreme California drought,
water became scarce and temperatures soared in the Sacramento River.
Jon Ambrose: During the summer of 2014 and 2015,
the eggs that were incubating,
we estimate that the rate of mortality was approximately
95 to 96 percent.
While temperatures below Keswick spiked,
temperatures in the McCloud River
still remained suitable as spawning habitat.
And this further emphasized the need
to get these fish back up into their historical habitat.
[♪]
Narrator: Reintroduction efforts have started,
so far into Battle Creek in the Central Valley.
Providing access to the native habitat above Shasta Dam
will be more challenging,
and the Species in the Spotlight Initiative is
bringing communities together to rally behind the effort.
In the meantime, many more threats to recovery
are also being addressed.
Noah Oppenheim: The Central Valley is a highly engineered system.
This was once one of the largest floodplain habitats
in the northern hemisphere.
Narrator: Natural, vegetated, and meandering river banks
have been modified to steep-sided channels,
which disconnects the river from its floodplain.
This has limited salmon's access to slow-moving,
food-rich water that historically provided
vital habitat to young fish.
Roger Cornwell: What we're finding out
is areas like behind me, the actual floodplain
is where they need to be.
It's teeming with life, and they grow at such rapid rates,
almost 3 or 4 times as they travel through the slower food-rich water.
Narrator: In addition to reestablishing access to the floodplain,
some farmers are seasonally soaking their fields.
After a few weeks, they will pump the food-rich water
back into the mainstem river to enrich the food supply.
Juvenile fish also face many more obstacles
while headed downstream to the ocean,
like water diversion pumps that can injure them,
or draw them off-course.
Scientists implant acoustic tags that can track
where they are in the watershed,
which helps diversion facilities minimize interactions.
And you can help too.
You can support land-use plans that
allow both fish and farming to thrive.
And get behind local landowners, tribes, and other groups
that endorse re-introducing winter-run Chinook
to their native high-elevation spawning habitat.
Brian Ellrott: In one sense,
the recovery of winter-run Chinook salmon is easy.
We know what the major threats are.
We know what to do, and we know how to do it.
And, we have stronger partnerships than we've had ever.
Rachel Johnson: And so that gives me a lot of hope,
that working together with our partners
and our agency's focus on moving the needle with them,
I think we have a fighting chance.
[♪]