|
By Shawn Blore
Out on the back deck of the Vancouver Aquarium,
human and animal eye each other. Both
want
something. The human wants the animal
to
move, to obey. The animal-a male Steller
sea lion-wanta to stay where he is.
Head high, neck arched, masaive cheast
thrown
forward, the Steller stands as proudly
as
an officer on parade. Woody is his
name.
His trainer has just noted down his
weight
on a clipboatd: 165 kilograms. Woody
is only
two-and.a.half years old. When he reaches
maturity at age eight, he'll tilt the
scale
at more than 1,000 kilograms, about
the same
as a 4x4 vehicle. Already, when he's
disinclined
to move, Woody can stick to the ground
as
if his flippers have been set in concrete.
"They get that look in the eye.
You
know that if you push them any further,
they're
going to try and put your face into
the deck,"
says his trainer.
It's an evolutionary trait. During
the mating
season, mature male sea lions battle
for
control of territory and fertile females.
Only the ones who don't budge, who
can intimidate
or fight off the others, get to breed.
Survival
of the fittest, or at least survival
of the
fittest genes. Woody is a modern example
of a species that has survived in inhospitable
climates for more.than 20 million years.
His trainer, Chris Porter, weighs some
70.odd
kilograms. His kind have been on the
planet
a mere two million years. Porter's
Success
as a trainer depends on his winning
these
contests of will, but that doesn't
diminish
his admiration for the Stellers. They
have
pride. It's part of their appeal.
It's also why most aquariums won't
touch
them. The Vancouver Aquarium is one
of only
two facilities in North America-and
one of
only a few worldwide-that keep Stellers.
For other aquariums, they're simply
too big,
too proud. The Vancouver Aquarium would
likely
have baulked at the suggestion of housing
Stellers if it were simply for the
amusement
of the public, or even its education.
But
Woody and his five companions are here
for
an altogether more serious, even macabre,
purpose. They're helping to solve a
mystery:
that of their own possible extinction.
Eumetopias jubatus, as the Steller
sea lion
is known scientifically, once ranged
all
the way round the North Pacific rim,
from
the top of Japan, up along the fringes
of
the Russian and American Aleutians,
down
the coasts of Alaska and B.C., and
all the
way to California. At their modern-day
peak
in the 1970s, the population numbered
more
than 250,000.
Then they started dying.
The decline began to get serious around
1980.
When the spotter planes flew over in
1979,
just over 125,000 Stellers were counted
in
the heart of the animal's range-the
Alaska
coast-line between Kiska laland in
the far
western Aleutians and the Kenai Peninsula
just west of Pnnce-William Sound, where
the
Alaska coast does a right-angle bend
toward
the south. Ten years later, there were
just
over 30,000. Rookeries-barren nubs
of rock
in the open sea where Stellers give
birth
and breed-that once teemed with tens
of thousands
of sea lions held only a few hundred
animals.
Despite this obvious cataclysm, the
National
Marine Fisheries Service, the American
government
agency responsible for the welfare
of most
Pacific marine mammals, was as difficult
to prod into action as a stubborn male
Steller.
Greenpeace finally sued the agency
on the
Stellers' behalf in 1989, and only
then did
NMFS budge, issuing an emergency decree
listing
in 1990 listing the Steller as "threatened"
under the Endangered Species Act, two
categories
away from "extinct". By that
time,
nearly 80 percent of the sea lions
in the
Kenai-Kiska area were gone, and the
decline
showed no signs of stopping. For the
Stellers,
prospects were bleak.
But for a 32-year-old postdoc working
at
a Department of Fisheries and Oceans
lab
in Nanaimo, things were looking up.
Dr. Andrew
Trites-a stoutish man, with dark, curly
hair
and a quick laugh, who resembles nothing
so much as a well-fed Columbo-was (and
is)
a bit of an anomaly in the marine-biology
world. Normally, people are drawn into
the
field by a keen interest in marine
animals.
Trites was different. "I certainly
had
no particular fascination with marine
mammals
as a kid," he says. "I mean,
I
watched Flipper like everybody else.
That
was about it."
Trites's first love was not animals
but numbers,
equations, and mathematical descriptions
of the way whole populations of animals
functioned
in an ecosystem. "I remember in
my fourth
year of biology," says Trites,
I read
an article about the Antarctic system:
someone
had put together a very simple set
of equations
that described the basic predator/prey
relationships
between blue whales and kriIl. I was
just
fascinated." Several years later,
in
his own PhD thesis, which carried the
somewhat
literary title of The Decline and Fall
of
the Pribilof Fur Seal, Trites presented
an
exquisite mathematical explanation
for the
near-total disapearance of the northern
fur
seal.
Fascinating stuff. But in an era when
most
of the research money (and, hence,
most of
the university careers) seems to gravitate
around ever-tinier but potentially
profitable
things like genes, chromosomes, and
DNA strands,
choosing population biology as a field
was
a questionable career move.
So for Trites, the Steller's untimely
demise
was serendipity itself. The Mystery
of the
Disappearing Sea Lion offered perhaps
the
perfect foil for his particular set
of research
skills. Large scale die-offs of marine
mammals
aren't exactly new. In fact, these
incidents
have become common enough that some
environmentalists
have likened marine mammals to mine
canaries:
their deaths provide an early warning
about
the presumably dire state of the planet's
health. The epidemic among the seals
in Europe's
North Sea was typical of such incidents:
the first clue that something was rotten
was the bloated corpses of seals washing
up on swimming beaches in Denmark (and
Holland
and Germany and Scotland). Not surprisingly
finding the cause of such a mass exterminations
is a job for a pathologist.
With the Stellers, however, not single
corpse
was found, even thougl through the
'8Os more
than 10,000 sea lions a year were disappearing
from southwestern Alaska. Even more
intriguing,
the Stellers weren't the only creatures
suffering:
harbor seals, fur seals, and fish-eating
seabirds such as thick-billed murres
and
red-legged kittiwakes were also declining.
It pointed to a system-wide cause,
something
most easily found by someone with a
penchant
for analyzing whole ecosystems. E ven
so,
no ecosystem can be analysed witbout
the
data with which to make comparisons.
SCIENCE WORKS by making comparisons.
Health
scientists compare the life spans of
smokers
and non-smokers. Drug tests compare
the symptoms
of people who received a drug with
those
of people who didn't. For wildlife
scientists,
however, things are rarely that simple.
If
an animal population goes into decline,
normally
the only thing to compare it with is
the
past, the good old days when the population
was healthy. That works if there is
rasearch
going back 50 or 100 years, but In
this case
there isn't. Lacking fur or ivory or
sellable
blubber, Stellers were never really
worth
hunting; as a result, they were never
really
worth studying. Even the most basic
infortasation,
like census data, has only been collected
systematically since the late 195Os.
Without
a historical database, researching
the Steller
decline could have been enormously
difficult.
Nature, however, contrived in this
case to
make comparisons relatively simple
by providing
two populations with radically differing
fortunes. In the Aleutian Islands and
the
Bering Sea, nearly three-quarters of
the
population has disappeared, but in
British
Columbia and along the Alaska Panhandle,
Stellers are holding their own, even
increasing.
Broadly speaking, solving this mystery
was
a matter of finding the crucial difference
between these two populations. It's
like
playing that old Sesame Street game
of "One
of these things is not like the other."
In fact, all Trites needed to begin
solving
the case was a client, someone to hire
him
to do the investigation.H is employer
at
the time, the Department of Fisheries
and
Oceans, wasn't likely to ask him to
take
on the job. Marine mammals have never
been
much of a priority at DFO. Not that
there
aren't plenty of critters to study.
The waters
lapping Canada's West Coast are home
to at
least a dozen species of marine mammals:
seals and dolphins swim, sea otters
play,
killer whales hunt, sea lions brawl,
humpbacks
and grey whales breach. It's just that
DFO
doesn't much care. Fish are what counts.
DFO employs exactly one full-time marine-mammal
biologist in all of B.C. He studies
how many
fish marine mammals eat. If fisha didn't
need something to swim in, DFO would
have
dropped "Oceans" from the
letterhead
long ago.
Fortunately, the mystery had caught
the attention
of others-a group of people-whose fate
was
so tightly caught up with that of the
Steller
sea lion that they were intere sted
in financing
a research effort. What's more, they
had
pockets deep enough to do it. That
group
was the Alaska fishing industry. Their
interest
stemmed fmm a very simple fact: their
presence
is the most obvious difference between
the
two Steller populations. Very little
trawl
fishing goes on in southeast Alaska,
where
the Stellers are thriving. The western
Gulf
of Alaska and the Bering Sea, on the
other
hand, are the site of the largest single-species
fshery on Earth.
Picture a boat the sire of a BC car
ferry,
with a net that could swallow the Hotel
Vancouver.
That's an Alaskan factory trawler.
There
ase no such ships in the waters of
southeast
Alaska, where the Stellers are thriving,
but in the Bering Sea and the Gulf
of Alaska,
65 such behemoths prowl. In 1995, they
landed
1.3 million tonnes of pollock, a Pacific
member of the cod family that usually
makes
its way to the table as fake lobster
or crab.
Half again as much in less-desirable
species
was tossed over the side as bycatch.
The
trawl-fishing industry generates billions
of dollars every year, and the Steller
sea
lion could put an end to it all.
<< Back to Magazine Features
|
