A STORY:
OTTERS V. CLIMATE
CHANGE
( Music)
IT’S A BEAUTIFUL DAY ON THE
WASHINGTON COAST
BUT THESE HIKERS AREN’T HERE FOR
THE SPECTACULAR VIEWS.
Anita: I think there’s a group of like four?
Ron: It’s grooming like crazy, so it’s probably
getting ready to rest. Just coming up onto the
rock. Oh it’s got a pup!
Ron: Each year in July, we do this annual
census.
We’ve got three adults….
FOR NEARLY 40 YEARS RON JAMESON
HAS BEEN MONITORING THE SIZE AND
HEALTH OF WASHINGTON’S SEA OTTER
POPULATIONS.
Ron: Most years, we can get up to you know,
130, 150 sea otters.
AND NEW RESEARCH SUGGESTS MORE
REASONS TO KEEP AN EYE ON THEM. IT
TURNS OUT THAT OTTERS PLAY A KEY
ROLE IN COMBATTING CLIMATE CHANGE
BY PROTECTING UNDERWATER KELP
FORESTS.
LIKE ALL PLANTS, KELP SEQUESTERS
CARBON DIOXIDE FROM THE
ATMOSPHERE TO CREATE ITS LEAFY
STRUCTURE.
IN FACT, KELP FORESTS ARE ONE OF THE
WORLD’S MOST EFFICIENT ABSORBERS
OF CO2.
BUT KELP FORESTS NEED SEA OTTERS
AROUND TO DEFEND THEM FROM
PREDATORS.
AND THE SURVIVAL OF OTTERS HAS BEEN
ANYTHING BUT GUARANTEED.
( music)
FROM THE MID 1700s TO THE EARLY
1900s, SEA OTTERS WERE WIDELY
HUNTED FOR THEIR LUXURIENT FUR.
Shawn Larson: It was the most valuable fur
that fur traders could get their hands on.
Shawn Larson: And many sea otter
populations were wiped out throughout their
range … from Russia and Japan, all the way
through Alaska … and all along the West Coast
of the United States, including in Northern
California, Oregon and Washington.
BY THE END OF THE FUR TRADE IN 1911,
ONLY ABOUT A THOUSAND SEA OTTERS
REMAINED IN THE ENTIRE NORTH PACIFIC
OCEAN.
BUT IN THE 1960s AND EARLY 1970s THE
U.S. FISH AND WILDLIFE SERVICE AND
SEVERAL STATE AGENCIES SET ABOUT
RESTORING THEM TO THEIR FORMER
RANGE.
Archival narrator: “The C-130 cargo aircraft can
accommodate 60 sea otters.”
SOME 700 SEA OTTERS WERE CAPTURED
IN ALASKA AND RELOCATED TO
WASHINGTON, OREGON AND BRITISH
COLUMBIA.
Archival narrator: “They’re in good condition
when they arrive, and they take to the waters of
Oregon as if this were their home.”
Shawn Larson: Only about a few dozen sea
otters were moved to Washington state. And of
those we think about a dozen survived to found
the population that now numbers about 1,100
animals off the coast of Washington.
SINCE 1989 WASHINGTON’S SEA OTTER
POPULATION HAS GROWN ROUGHLY
EIGHT PERCENT A YEAR. IT’S ONE OF THE
HEALTHIEST POPULATIONS ON THE WEST
COAST.
THAT’S GOOD NEWS-- NOT JUST FOR THE
OTTERS BUT ALSO FOR THE KELP.
BECAUSE SEA OTTERS LOVE TO EAT A
CREATURE THAT THREATENS THESE
UNDERWATER FORESTS.
SEA URCHINS ARE SMALL, SPIKY
CREATURES THAT PLAY A SURPRISINGLY
LARGE ROLE IN THE KELP FOREST
ECOSYSTEM. IF LEFT UNCHECKED,
URCHINS WILL DEVOUR KELP AT AN
ASTONISHING RATE. FORTUNATELY,
URCHINS ARE A FAVORITE FOOD OF SEA
OTTERS.
Kristin Laidre: Sea otters have a very high
metabolism and they eat up to 25 percent of
their bodyweight per day. And when the sea
otters go down and remove those urchins you
end up actually having a big growth or bloom of
that kelp because it no longer has urchins to
kind of graze it down.
Ron Jameson: And when sea otter predation is
removed, the urchin populations just basically
explode. … they become so abundant that they
can actually graze the ocean bottom down to
what’s often referred to as urchin barrens.
Shawn: And then it just looks like an
underwater desert with just urchins there.
( breathing in mask, splashing)
BOB SIZEMORE COUNTS SEA URCHINS
OFF THE WASHINGTON COAST TO KEEP
TABS ON THE SIZE OF THE POPULATION
Bob: We began doing these surveys in the
early 1980s so we have almost 30, 35 years of
data. So we can track the population when it
goes up and when it goes down, and then try to
assign a reason why that’s happening.
When I started here in the early 1990s, urchins
were very abundant throughout the entire
Straight of Juan de Fuca.
There was urchins everywhere. they’ve been
called carpets of urchins.
THESE HERDS OF URCHINS OCCUR WHEN
AN ECOSYSTEM FALLS OUT OF BALANCE.
IN HEALTHY SYSTEMS SEA OTTERS AND
OTHER TOP PREDATORS KEEP URCHIN
POPULATIONS IN CHECK. THAT ALLOWS
KELP TO GROW AND TO SEQUESTER
MORE CARBON.
IN WASHINGTON STATE, IN THE MID 1990s
A GROUP OF MORE THAN 100 SEA
OTTERS WANDERED INTO THE STRAIGHT
OF JUAN DE FUCA. THEY STAYED THERE
FOR MORE THAN THREE MONTHS
FEASTING ON URCHINS.
Bob Sizemore: We heard about the sea otters
coming in, and so we went back into that
location and surveyed again. And what we
found was amazing.
( Music)
Basically the sea urchins were gone. The only
sea urchins we saw were very tiny ones and
they were tucked inside the cracks and
crevices of the rocks.
IN A MATTER OF WEEKS, THESE OTTERS
DEVOURED UP TO A MILLION POUNDS OF
URCHIN.
Bob: To see that change overnight was
amazing, as a biologist and just as a diver. It
was a pretty dramatic change.
AS WEST COAST SEA OTTER
POPULATIONS HAVE REBOUNDED, SO
HAVE THE KELP FORESTS. AND IT’S
HAVING A MEASURABLE IMPACT ON
CLIMATE CHANGE.
ACCORDING TO A RECENT STUDY, KELP
FORESTS CAN ABSORB UP TO TWELVE
TIMES MORE ATMOSPHERIC CO2 WHEN
SEA OTTERS ARE KEEPING WATCH. AND
ALL THAT CARBON CAN REALLY ADD UP.
THE CARBON SEQUESTERED EACH YEAR
BY NORTH PACIFIC KELP IS EQUIVALENT
TO TAKING AS MANY AS SIX MILLION
PASSENGER CARS OFF THE ROAD.
Kristin Laidre: We know that top predators play
a big role in ecosystems. Sea otters are an
example where they really could have an effect
on carbon storage because of the blooms in
kelp with their presence. And I think most
certainly there are other possibilities in either
marine or terrestrial systems where that could
be the case.
If conserving a predator can also have a
positive impact on carbon storage or on kind of
fighting climate change, that’s certainly a win,
win.
Ron Jameson: It was one of those situations
where human beings were able to right
something that was wrong. And we don’t get
that opportunity very often and often when we
try to do something like that we fail. In this case
I think we succeeded.
QUEST SPOTLIGHT
BUMP: :05
( Music)