By
MARLA CONE, LA Times Environmental Writer
ADAK ISLAND,
Alaska--There are few places on Earth that have changed so much,
so fast as the narrow arc of islands where the Pacific Ocean greets
the Bering Sea.
The Aleutian
Islands are in the middle of nowhere. No tourists, no cruise ships,
no chartered fishing trips, no quaint country inns. On a quiet
day, when the turbulent seas and legendary winds are still, you
can hear a killer whale breathe.
But look
and listen more closely. Something is missing.
Where are
the sea lions, fat and happy, napping on the rocks and barking
at their pups? And the furry sea otters crunching on urchins?
What became of the ample king crabs and shrimp, and the schools
of silvery smelt? And where are the lush undersea forests of kelp
that provided food and refuge for fish?
As sudden and savage as an Arctic storm, some mysterious phenomenon
has transformed this spectacular archipelago of more than 1,200
miles in just a handful of years.
A vast subarctic
ecosystem is collapsing. No one knows why.
The sudden changes in the Gulf of Alaska and the Bering Sea have
inspired an eclectic team of men and women to try to solve an
extraordinary environmental whodunit. Virtually alone in a forbidding
wilderness closer to Siberia than to Anchorage, they have been
divebombed by eagles, bitten by otters, buffeted by 70-mph winds,
rattled by earthquakes and lost in storms. And each year they
return for more, drawn back by the Aleutian paradox. If this rugged,
remote ecosystem is collapsing, can any place on Earth be safe?
Jim Estes, a marine ecologist at the U.S. Geological Survey in
Santa Cruz, has traveled to the Aleutians for the last 30 summers,
studying what once was the world's largest and healthiest population
of sea otters. Three summers ago Estes realized that the otters
had virtually disappeared while he watched.
There were no bodies to dissect, few clues to decipher. The otters
aren't starving. They aren't sick. They have simply vanished.
Throughout
the Gulf of Alaska and probably the Bering Sea, too, the balance
of prey and predator has been upended, a transformation so extreme
it's called a "regime shift." Waters once brimming with
seals, otters and king crab are now dominated by sharks, pollock
and urchins. Virtually no creature remains untouched.
"You
just can't grasp how different things were 10 years ago,"
said Estes during a recent expedition. "No one has ever seen
a decline of this magnitude in such a short period of time over
such a large geographic area."
Piece by piece, over the last three years, scientists have started
to solve the puzzle. Clues point toward something--almost imperceptible--that
happened in the ocean in 1977. But the answers are more disturbing
than satisfying, more elusive than conclusive. It seems the ocean's
chain of life is actually a fragile silken web. If you remove
a strand, the whole thing unravels. And it may never be whole
again.
An Unprecedented
Population Loss
Tim Tinker
is swathed in a bulky orange survival suit, hanging from the bow
of a 25-foot boat as it hugs the rugged shore of Adak Island.
A brutal storm
has just ended, leaving August skies crisp and clear. Adak's mountains,
set against a blue satin sky and fog as white as cotton balls,
are draped with a luxuriant fleece blanket of moss. The green
shines so brightly it seems as if it could glow in the dark. Overhead,
a bald eagle soars, and black and white puffins skim across the
surface of the sea, their orange webbed feet splashing the 40-degree
water.
From his perch
on the bow, Tinker lifts his binoculars, training them on rocky
reefs. For the ninth straight year, he is counting the Aleutians'
sea otters for an annual survey. He scans a reef, lowers his binoculars
and turns toward the stern of the boat, holding up a single finger
clad in ragged wool gloves.
Iris Faraklas, a research assistant, dutifully makes a notation:
One otter.
An hour into the survey, Tinker, a marine mammal biologist at
Santa Cruz, and his colleague Brian Hatfield have counted only
five otters and two harbor seals.
"Back
in the old days, in the early '90s, we probably would have seen
500 otters by now," said Estes, as he pilots the boat around
submerged rocks and into foggy inlets. "Now we go miles and
miles without seeing even one."
This day, they will survey 200 miles of coast, finding only 171
adult otters and 29 pups.
If sea otters
dream, they are surely dreaming about a place like Adak Island,
in the middle of the Aleutian chain. There's plenty of food. Plenty
of sanctuary. But only one otter per mile.
In the 1980s,
as many as 100,000 otters inhabited the islands. Today, only about
6,000 remain, according to aerial surveys. Between 1992 and 2000,
the population dropped by 70%, a rate of decline that researchers
say is unprecedented for any mammal population in the world.
"What's
really horrifying is that the Aleutians have always been considered
the stronghold of otter populations," said Rosa Meehan, who
heads the marine mammal office of the U.S. Fish and Wildlife Service
in Anchorage.
"At one
time, 80% of the world's population of sea otters were out there,"
Meehan said.
Now, the
wildlife agency has declared otters a candidate for endangered-species
protection, although only in western Alaska.
In 1995, when
they began to notice the signs of a population decline, Tinker
and Estes, who specialize in otter behavior and population biology,
at first looked for signs of disease, famine or reproductive troubles.
They found none.
For a couple of years, as the decline steepened, they were baffled.
If thousands of otters had died, where were the bodies?
Then it dawned
on Tinker: Perhaps the animals were being eaten.
By killer whales.
Estes was
disbelieving at first. For orcas, which are voracious predators,
otters are little more than hairballs. Snack food for a killer
whale.
Still, Estes
remembered spotting an occasional killer whale lurking close to
shore over the years. And it did seem odd that most of the surviving
otters were in a small lagoon on Adak--unreachable by killer whales.
He decided to test the theory. In 1997, Estes and Tinker packed
up a dead otter on Amchitka Island and flew it to California,
where a colleague ground it up in a giant blender, calculated
its calorie load and compared it with how many calories a killer
whale consumes.
It turned
out that fewer than four whales--3.7 to be exact--could have eaten
40,000 otters in five years.
"We were
absolutely blown away," Estes said.
But orcas
had lived in harmony with otters for thousands of years on the
Aleutians. Why, all of a sudden, were they preying on them so
heavily?
To find the answer, biologists simply had to follow the food chain.
Orcas customarily
feed on sea lions and seals, which are packed with high-calorie
blubber. But the population of Steller sea lions, the world's
biggest sea lions, took a sharp dive in the late 1980s. Harbor
seals also declined at a similar rate.
By 1992, otters
were the only plentiful marine mammals left in Aleutian waters.
The orcas, in their hunt for calories, apparently had been forced
to switch prey.
The effects
cascaded rapidly down the food chain.
With far fewer
otters around to eat them, sea urchin populations exploded--increasing
eight-fold within a few years. As many as 100 of the spiny green
creatures now cover each square foot of ocean floor around the
Aleutians.
The urchins, in turn, ate the kelp.
In 1993, kelp
forests were 20 feet deep and so thick they clogged the engines
of Brenda Konar's dive boat. "Now the only kelp you find
is the stuff right by the shoreline, and it's maybe only three
feet deep," said Konar, a biologist with the School of Fisheries
and Ocean Sciences in Fairbanks.
When the leafy
undersea forests vanished, so did many of the rockfish, snails,
starfish and other creatures that use the kelp for food, shelter
and breeding grounds. Some local seabirds, mainly puffins and
kittiwakes, also are hurting from lack of fish.
The Aleutians
offer proof that one small ecological change can move like a tsunami
throughout the entire ocean realm. Yet the snarl in the food web
had to begin somewhere. Where, scientists wondered. And, even
more important, who--or what--did it?
A Tough
Place for Nature Studies
In Alaska,
August is prime tourist season. Fishermen from around the world
flock to its coastline and lug ice chests home packed with salmon
and halibut. But not in the Aleutians. Hardly anyone ventures
here.
It's a four-hour
flight from Anchorage to Adak, and from there, it's 38 hours by
ship to Attu, which sits 1,200 miles off the mainland, on the
far western edge of the chain, next to Russia.
It's not easy
to chronicle nature in a place so inaccessible, so forbidding.
For a month each year, the research team travels to Adak and Attu,
counting otters and collecting fish, urchins and mussels for tests.
They work at sea from daybreak to nightfall, taking advantage
of summer daylight, which in this part of the world lasts 15 hours.
Along shorelines known to be treacherous to navigators, Tinker,
Hatfield and Estes logged a thousand miles this August in their
25-foot boat.
Part seaman
and part scholar, Estes over the last three decades has weathered
just about anything this extreme environment can offer.
One August on Attu Island, Estes and two colleagues almost died
when their boat engine failed and an unexpected winterlike storm
hit. The three hiked for nearly three days, covering maybe 100
miles. A student researcher--a triathlete--suffered hypothermia
and Estes was forced to consider abandoning him to die. They found
their way back to camp through more luck than skill, Estes recalls.
No wonder
events on this archipelago go largely undetected. In 1986, the
largest earthquake recorded in North America--a magnitude 8.0--struck
the Aleutians. Hardly anyone was around to notice.
But proximity
to people is not always the best indicator of environmental damage.
There are no clear-cut forests. No rows of red-tiled roofs. No
industrial smokestacks. This wilderness still looks as nature
intended. And there lies the paradox.
"Anybody
that comes to Alaska says 'My God, this place is beautiful!' They
look at the puffins and see a bald eagle and it's a pristine,
incredibly breathtaking place to be," said Bruce Wright,
a division chief at the National Marine Fisheries Service in Alaska.
"But without spending time out there doing long-term monitoring
to understand the changes that are taking place, that's just a
superficial look."
It was almost
a fluke that Estes and his team witnessed the ecological changes
here. Ironically, Estes initially was drawn to the Aleutians because
of their bounty of life. He was trying to figure out why California's
otters were hurting while Alaska's were thriving. Now he's haunted
by a suspicion that other ocean realms could be undergoing similar
dramatic changes--it's just that no one is around to watch.
1977 Event
May Have Been Trigger
On the Pacific
side of Adak Island, needle-sharp spires crafted by ancient lava
jut out from the sea--sentries guarding the shoreline. Everything
about these volcanic islands seems eternal, as if you could return
every year and nothing would ever change.
But the Aleutians
are a dynamic place, ever-changing. Fog shrouds the islands one
instant and retreats the next. Hurricane-force squalls descend
with little warning. The environment of the Aleutians, however,
isn't supposed to be as capricious as its weather. Ecosystems
normally evolve slowly.
"I have
not come across any other example of such a total flip-flop"
of an ocean environment, Wright said.
Ecological
shifts as sudden and sweeping as the ones in the Aleutians usually
can come only from human interference, said David Lindberg, an
evolutionary biologist at UC Berkeley. If the shift were natural,
animals and plants of the Aleutians would have evolved with some
defensive strategies, he said.
"We're
incredible, as a species, at speeding up changes," Lindberg
said.
Scientists are exploring many factors--global warming, overfishing,
pollution--that might have played a role in the Aleutians' misfortunes.
Looking back, they theorize that the key event may have come in
1977, when a sudden warming--just two degrees Celsius--in the
average temperature of the Gulf of Alaska was recorded.
The Arctic
has been especially vulnerable to climate change, which many scientists
believe is caused in part by worldwide burning of fossil fuels
and production of greenhouse gases.
Although they
cannot know for sure, researchers believe the chain of events
was most likely this:
Warmer water caused plankton--short-lived and ultra-sensitive
to temperature changes--to disappear. Tiny copepods and krill
probably followed quickly.
The shrimp and crab, along with smelt fishes such as capelin and
herring, would have vanished afterward, deprived of their food,
to be replaced by an explosion of cod and pollock. Once-thriving
shrimp and crab fisheries collapsed in the late 1970s while the
new species attracted large fishing trawlers that descended on
Alaska, harvesting millions of tons of pollock and cod a year
for American and Japanese consumers.
By the mid-1980s,
the problems spread to young mammals.
The decline
of the smelt fishes probably triggered the collapse of the seal
and sea lion populations, say marine mammal biologists, including
Kathy Frost of the Alaska Department of Fish and Game. The smelt
are high in fat, and without them, baby mammals might not find
enough calories to survive the winters.
But salmon
like warmer water. Their populations have increased, drawing sharks,
which feed on salmon and--at times--on seals and sea lions.
All of a sudden, the Aleutians had turned into a predator pit,
unsafe for marine mammals.
So far, the
rest of Alaska has escaped the regime shift, presumably because
waters elsewhere around the state have different ocean circulation
patterns and have not warmed.
Commercial
fishing of pollock and cod may be exacerbating the food shortage
for the mammals. In July, a federal judge ordered the U.S. government
to ban commercial fishing around the Aleutians to protect endangered
sea lions. Before the ban, nearly every fish filet sold at U.S.
fast-food outlets had come from Aleutian waters.
Commercial
fishermen in Alaska say it is unfair to blame them. Pollock are
still plentiful and they had never harvested the capelin and other
smelt important to sea lions. But environmentalists argue that
the huge trawling operations are now taking the only food left
for the animals.
Scientists
are only beginning to try to figure out what role pollution might
be playing in the ecological shift.
Pollutants
have drifted to the Aleutians from thousands of miles away. Bald
eagles that never leave the islands are contaminated with DDT,
a pesticide apparently never used here. Air and ocean currents
in the North Pacific move in a clockwise pattern, which means
pollutants from Asia move toward the Aleutians.
And the U.S.
military, which recently shut down a base on Adak, left behind
PCBs, polychlorinated biphenyls, which can harm animals' reproductive
and immune systems. Estes' team was shocked to learn that otters
on Adak are twice as contaminated as ones in California and 10
times as contaminated as otters elsewhere in Alaska.
"It's
such a land of contrasts here," said Walter Jarman, an expert
on pollutants from the University of Utah. "There's something
so contradictory about a place that is this beautiful and remote
and contaminated," he said as he stood next to a pile of
unrecognizable military debris in a grassy field on Adak. "We
have an unfortunate laboratory here."
Still, Jarman
suspects that the military pollution has not been the driving
force behind the otter and sea lion problems, since the population
crash has been documented even on islands with no PCBs.
"My gut
feeling is that it's not connected," he said. "But,
from the very beginning in the Aleutians, we've been wrong a lot."
The Aleutians
are so unpredictable that scientists may never be able to unravel
all the biological interactions and prove or disprove their theories
about how the food web got tangled.
"It
drives people crazy when you don't give them a straight answer,"
said Frost of the state wildlife agency. "But it's an unbelievably
complicated place, and biology is not a very clean science. Animals
are like people. There is never one factor at play. . . . Sometimes
you poke along and poke along and all of a sudden, the pieces
fall into place."
Some experts
say the ocean may be shifting back, favoring the marine mammals
again instead of the sharks and pollock. If it does, Estes and
his team will be there to chronicle it.
But even if
all the elements--the forage fish, the otters, the sea lions,
the kelp--were to return, these islands will never be the same.
Like marble chips in a kaleidoscope, they would fall in different
patterns.
"I'm
not going to see it recover in my lifetime," Estes said.
From the three
decades of snapshots he carries in his head and the three decades
of data stored in his computer, Estes knows this wilderness is
no longer unspoiled. But, when he steers the boat past a delicate
waterfall, knowing few humans will ever see it, the Aleutians
still feel wild to him. And that sensation, decidedly unscientific,
gives him hope. He will be back next year.
A Shifting
Balance
Alaska's
remote Aleutian Islands have always been an oasis for marine life.
But this subarctic ocean ecosystem has undergone a dramatic transformation
in recent years.
Waters that
brimmed with marine mammals, crab, shrimp, forage fish and kelp
are now dominated by urchins, sharks and groundfish like pollock
that do not provide a high-calorie diet for marine animals and
birds. Sea lions, seals, otters, shrimp and crab have almost disappeared,
and some seabird populations are declining.
Scientists
speculate that global warming is the culprit. Gulf of Alaska temperatures
have risen by 2 degrees Celsius in the past 20 years. Also, intensive
commercial trawling is reducing fish populations.
Sources: National Marine Fisheries Service, U.S. Geological
Survey
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