Page 28 - ARUBA TODAY

A28 SCIENCE
Friday 18 May 2018
Sea otters rebound but struggle to regain historic range

By ELLEN KNICKMEYER of Fish and Wildlife.
MOSS LANDING, Calif. (AP) Kelp forests are vital to
— While threatened south- coastal life, serving as un-
ern sea otters bob and derwater hiding places,
sun in the gentle waves of food stores and nurseries.
this central California estu- When otters venture into
ary, wildlife experts up and the undersea areas eaten
down the West Coast are bare by urchin, they are
struggling to figure out how easily spotted by one of
to restore the crucial coast- their main predators, the
al predator to an undersea great white shark.
world that's falling apart in Great-white shark attacks
their absence. on southern sea otters have
Southern sea otters, nearly surged at least eight-fold
wiped out by centuries this century, becoming the
of industrial-scale hunting biggest killers of the otters,
for their fur pelts, have re- marine experts say.
bounded from as few as The sea otters, unique
50 survivors in the 1930s to among marine mammals,
more than 3,000 today, are more fur than blub-
thanks to federal and state ber, so sharks typically only
protection. take a test bite and move
But there's a problem. In this photo taken Monday, March 26, 2018, a sea otter dives to the bottom of its exhibit at the on. But the otters often die
Southern sea otters, a top Monterey Bay Aquarium in Monterey, Calif. anyway.
carnivore that normally Associated Press In areas with kelp cover for
helps keep other popula- the otters, shark bites drop
tions in check and ecosys- At the former whaling town warm. the restoration of a preda- to almost nothing, Nich-
tems in balance, "are kind of Moss Landing, the re- Efforts to get the southern tor, it isn't easy. olson and aquarium col-
of stuck," says Teri Nichol- stored slough forms part sea otters back into more Sometimes, "it's the Hump- leagues found in a March
son, a senior research bi- of the southern sea otters' of their old range reflect ty-Dumpty syndrome," said report in the journal Ecog-
ologist at the nearby Mon- modern-day range: 300 growing global recognition Bill Ripple, an Oregon State raphy. To help the kelp,
terey Bay Aquarium miles of coast along the of the benefits of restoring University ecologist and commercial divers along
Despite decades of gov- middle of California. top predators to their his- professor who has found Northern California's Men-
ernment protection, south- On this morning, male sea toric territory. that only half of efforts to docino coast are tending a
ern sea otters today still oc- otters clasp paws with one After supporting wolf exter- restore land carnivores are precious stand of kelp for-
cupy only about a fourth of another for stability in the mination in Yellowstone in successful. est, plucking off the purple
their historic range. Federal water as they snooze to- the first half of the 20th cen- "During these cascading sea urchins by hand and
wildlife policy calls for wait- gether and warm their bel- tury, for example, the U.S. events that follow the loss using suction hoses to vac-
ing for the otters to spread lies in the spring sun. Deeper government by the second of the predators in the first uum them up, says Catton.
out again on their own. The into the waterway, female half was aiding wolves' re- place, we can sometimes Unlike red urchins, the spiny
otters' habitat hasn't really otters float with their young introduction to the national see the ecosystem fail to purple urchins are no one's
budged beyond their cur- perched on their chests, park. The wolves' hunting function," Ripple said. "And idea of a favorite meal,
rent central California en- or with newborn otters — have cut what were too- sometimes it's not real easy whether human or otter.
clave, however, over the even more buoyant than large herds of deer and to put those ecosystems Experts are trying potential
past 20 years. adults thanks to their thick elk. The result has been a back together." commercial uses for them,
"At this point, I think for the fur — bobbing alongside rebound at Yellowstone When it comes to southern including compost, in
population to increase, the them like corks. for all kinds of life — bea- sea otters, all but wiped out hopes of incentivizing their
range needs to expand," A hungry sea gull stalks one vers, fish, even aspen trees, long ago, "we don't even large-scale removal.
said Karl Mayer, manager female otter gnawing on some ecologists say. know what a normal en- And at Monterey Bay
of the aquarium's sea-otter a fat innkeeper worm. Her Wildlife officials have made vironment looks like," said Aquarium, where workers
program. It doesn't really otter pup watches wide- efforts around the world to Lilian Carswell, who coor- since 1984 have rescued
make sense, Mayer said, eyed. restore predators ranging dinates marine conserva- and returned to the wild
"to stuff more otters into a Though small by marine from birds of prey to bears, tion and sea-otter recovery about 280 stranded otters,
limited environment." mammal standards, sea sometimes controversially at the U.S. Fish and Wildlife otter-tenders are trying to
Mayer spoke as his boat otters are the largest mem- when people believe the Service. Populations of vo- habituate rescued young
putt-putted among sea ot- bers of the weasel fam- animals are a threat to racious purple sea urchins ones to seeking out purple
ters, harbor seals and peli- ily and males can grow to them or their livelihoods. have exploded along the sea urchins over crabs and
cans crowding the salt-wa- nearly 100 pounds (45 kilo- Some in the fishing indus- West Coast, owing to the other more appetizing fare.
ter estuary called Elkhorn grams). Their fur, the dens- try oppose the sea otter's more than century-long ab- Ultimately, California otter
Slough. est on earth, keeps them comeback. Fishermen in sence of the sea otter from experts may one day rec-
Alaska accuse the growing much of its old range, and ommend simply loading
northern otter populations to a mysterious die-off this otters into vehicles and giv-
there of consuming the red decade among sea stars, ing them rides to remaining
sea urchin humans eat as another coastal predator. kelp forests to repopulate.
sushi. Wildlife experts coun- Their numbers unchecked, Meantime, scientists
ter that the entire coastal purple urchins have helped scratch their heads over
ecosystem, including the destroy more than 90 per- what else to try. The last
valuable shellfish, faces cent of Northern California few centuries of human de-
collapse without otters and bull-kelp forest since 2014, velopment were enough
other predators to keep said Cynthia Catton, an to pull apart that network
things in balance. environmental scientist with of otter, kelp, urchin, shark,
Even when humans support the California Department and other species.q