Search for the missing Arctic cod
Scientists focus on actual number of vital fish
Ship icebound in the
PETER
CALAMAI
SCIENCE
WRITER
ABOARD CCGS AMUNDSEN—A blotchy, gelatinous fat thread
wriggles on researcher Louis Fortier's fingertip.
"It may look like something from your nose, but it is beautiful to us," Fortier says.
The snot-like strand is actually the larva
of the Arctic cod and one reason that scores of researchers have been working
here in
Better understanding the life history of
the Arctic cod is a crucial element in eventually forecasting how climate
change will affect the unique ecology of the
One impact is obvious, although the exact timing could be anywhere from a few decades away to the end of the century.
"The first consequence of climate
change is going to be thinner ice and more open water in the summer,"
Fortier says. "When the
But many possible biological and physical
changes can only be guessed at because so little is known about how Arctic
ecosystems operate in any season other than summer. That knowledge gap explains
why
Decommissioned as a
The ship provides comfortable living and working quarters for up to 46 researchers from Canada, Europe and Japan rotating through on stints of six weeks, although a few remain for 12 weeks. Many are graduate students, sharing projects with their professors and training as the next generation of polar scientists.
Such a floating research institute was the only way that researchers and their equipment could carry out investigations during the frigid sunless winter and — even more important — when the rays of the returning sun began stirring chemical and biological pots.
Right now, however, the Amundsen's carmine red hull was a dark smear about a half-kilometre from a research station on the ice where Fortier's team was working up a sweat on a minus-15C day trying to solve the Enigma of the Missing Arctic Cod.
The words are unconsciously capitalized
when spoken by Fortier, a professor from the
As Fortier explains to a non-scientist
visitor, there are actually two mysteries surrounding the cod and both must be
solved before any reliable predictions can be made about the impact of climate
change in the
This particular cod, scientifically known
as Boreogadus saida,
is a keystone species for the
The first mystery is that the predators seem to be eating more cod than would be sustainable. Based on consumption counts from predator stomach contents, the population of Arctic cod must be at least seven times greater than the best estimates based on surveys in order to feed those voracious seals, beluga whales and marine birds.
And it's not like the earlier estimates
were puny. In 1990, marine biologists working at
Before that study was published in 1996,
the gap between cod consumption and reproduction had been times 30. The
|
`It may look like something from
your nose, but it is beautiful to us' Louis Fortier, on the Arctic cod
larvae |
But as demonstrated by the fiasco of the
much bigger Atlantic cod, it's very difficult to accurately count something
that lives underwater and moves all the time. But if we don't know more about
where the Arctic cod live during different parts of the year, and how those
locations and environmental conditions shape growth and reproductive success,
then there is little chance of even guesstimating how climate change will effect the cod's future. And as the cod goes, many believe,
so goes the
One piece of the puzzle has been supplied by the ultrasensitive echo-sounder aboard the Amundsen. It detected a layer of fish starting at a depth of 140 metres and extending down toward the bottom at 225 metres.
But mere acoustical echoes aren't enough to scientifically resolve the enigma of the missing Arctic cod, so Fortier and his team have recently begun fishing on most days.
This is not recreational angling. Imagine handling a gill net that's 90 metres long in temperatures where water freezes to a glove in seconds. The net is lowered through a hole in the ice until one end reaches the bay bottom and then left for the better part of 24 hours.
Hauling up the net requires muscle power from Fortier and his four team members — Anna-Justin Prokopowicz, Michelle Pilote, Gérald Darnis and Luc Michaud — plus horsepower from a treaded tractor. When things go well, this operation can take 20 to 30 minutes. When there are hitches, it can take more than an hour, as it did one day this week. The yield was 31 small cod, most less than 15 centimetres, which had hatched from eggs last summer or the summer before.
"We can come up with their birthdays, even give them names and include them in the acknowledgements of the research paper we're going to write," Fortier jokes.
The birthday part is true, however. The cod's earbone, called an otolith, acts like the stump of a tree, with a new ring added every day. The width of the rings is an accurate guide to the growth rate of any individual fish.
Yet, this built-in date chip has spotlighted another mystery about the Arctic cod. In earlier research, Fortier discovered that a new generation of cod comes into its watery world at two different times in most years — a spring hatch in April-May and a summer hatch in June-July.
These observations were made in polynya, a Russian term for a half-dozen regions in
the
"You take a risk but if you do survive, you're going to be way bigger than the other guys," Fortier says.
The research team needed to capture these early-birth larvae and other organisms congregating at the bottom of the ice to learn more about the two kinds of larvae. To accomplish this, they devised an ingenious trawling technique that married Inuit traditional knowledge with modern technology.
When the Inuit wanted to pull a net under the ice, they would chop two holes three to four metres apart and pass a rope through the water by using a wooden arm that pivoted from an elbow.
The Amundsen researchers borrowed the wooden arm idea and combined it with gas-powered augers that can cut through even two-metre-thick ice in a matter of minutes.
Yet, Fortier and his team needed to pass their rope between two large rectangular openings that were 250 metres apart. That's a lot of ice augering and wooden arm bending for a necklace of holes along the way.
The rectangular openings need to be large to accommodate a metal frame which holds three plankton nets. The treaded tractor pulls this frame down one hole and up the other in just more than two minutes. The three nets face into the prevailing current and scoop up the marine life along the way.
Even the coarsest of the three nets will snare the larvae, funnelling them down to a "cod trap" canister at the net's end. The contents of that trap were poured into a Styrofoam cooler into which Fortier dipped his finger, and retrieved the wriggling cod larvae.
"We expect that as the climate here
warms, more and more of these areas along the margin of the
"But in the long run, if the ice cover keeps disappearing, then that reduces the habitat of the juvenile and adult Arctic cod because they use the ice to hide in. It would be easier for birds and seals to get their meals of Arctic cod," Fortier says.
The cod mysteries still remain, but one of
Additional articles by Peter Calamai
New face of Arctic research
Young scientists tackle mystery of climate change
PETER
CALAMAI
SCIENCE
REPORTER
ABOARD CCGS AMUNDSEN—The parka hood of
That's the case for 16 of the 40-plus
researchers here using
One example of this new generation is
Teresa Fisico, a 23-year-old
Fisico's main job here, however, isn't forecasting but research to improve a
specialized computer model for polar weather forecasting, a need that can only
grow if projected climate change brings an ice-free
"Understanding Arctic weather is one of the hardest things to do because we don't have data about real conditions," Fisico says.
The native of Huntsville, Ont., is closing that gap by hourly appearances on the ship's highest deck — even now with wind-chill temperatures in the minus-30s C — to check meteorological instruments and scan the usually clear sky, hoping for even a hint of clouds.
Clouds or other weather changes can justify launching a weather balloon that can rise 20 kilometres while radioing back readings of temperature, humidity and winds. In three weeks Fisico has loosed more than 30 such miniature radio transmitters from the ship's stern; several times she has had to work through the night.
The Amundsen is
named for the Norwegian polar explorer Roald Amundsen, who was the first to successfully navigate the
Last year, the Amundsen
was refurbished and outfitted with laboratories at a cost of $30 million. Since
November, the ship has been frozen into the sheltered ice of
|
Research has been sparked by Arctic sovereignty issue |
Fisico flew in at the beginning of April for a double shift,
three months that will see the ship shake off its icy straitjacket in mid-May
to head north into open water.
This chance for immediate Arctic research
persuaded Fisico to pass up an offer from McGill in favour of working with
It's a chance that hasn't been available to
many young university scientists in
The increase spending for Arctic research
has been sparked partly by the federal government's interest in reasserting
Arctic sovereignty, especially with the possible opening of the
"We've lost two generations of
researchers," the Amundsen's chief scientist,
Louis Fortier, told visitors to the ship from the eight-nation Arctic Council
last week. The current research revival was fuelled by the resurrection of the Amundsen, which had been rusting and was nearly derelict in
"There are definitely opportunities coming up for me in the new network," says an enthusiastic Fisico.
For the young researcher, it's the latest
stage in a journey into the realms of science initially ignited by watching a
shuttle launch as an 8-year-old, then nurtured by glider and pilot experience
through the Air Cadets in
Her story is just one example of the emerging generation of young researchers.
In a lab down in the bowels of the Amundsen, 27-year-old
In another lab, Karine Bibeau, a 24-year-old geochemistry master's student from McGill, is categorizing the organisms in mud from different parts of the bay bottom, testing conventional wisdom that Arctic waters are biologically bereft.
"I wasn't even thinking about starting my graduate work right away when I was told I had to decide in two days whether I wanted to join this leg of the trip," Bibeau says. "It was too good an opportunity to pass up. I can learn so much from the other researchers here on the ship because we're all here together for six weeks."
Additional articles by Peter Calamai
Struggles
of the polar bear
Climate
change threatens these Arctic mammals
Earlier ice breakup hampers bears' hunt for seals
PETER
CALAMAI
SCIENCE
WRITER
ABOARD CCGS AMUNDSEN—Andy Derocher and Ian Stirling were hunting polar bears from a helicopter last
week in the
"We thought they were a male and a female because one was considerably larger," Derocher says.
Hit by a tranquilizer dart from
"I don't like to anthropomorphize it, but polar bears are a lot more social than people give them credit for," Derocher says.
And also more tender, an unexpected description to apply to a 500-kilogram animal with claws that can gouge a furrow five centimetres deep in a rival's skull.
Yet, Derocher has seen mated males and females snoozing on the ice beside one another, powdery snow spread like a white duvet around their bodies.
Just as we are beginning to understand what
really makes polar bears tick, however, our society's dependence on fossil
fuels may wind up exiling the magnificent creatures from much of the
The bears face the loss of their natural habitat from climate change triggered by rising levels of greenhouse gases in the atmosphere, the main culprit carbon dioxide from burning coal and petroleum.
"I think the prognosis is very
grim," Derocher told an audience of Arctic
researchers based aboard
His forecast of how polar bears will be
driven hundreds of kilometres north by thinning sea
ice dovetailed naturally with the Amundsen's current
mission, which is to fit together all the pieces of the complex web of Arctic
life that eventually culminates in the polar bear. As well, one researcher on
this leg of the year-long mission, doctoral student John Iacozza
from the
In a country that is home to more polar
bears than anywhere else in the world, Derocher and
These long-term studies let the researchers
spot the first impact of climate change on the bears in
In 1992, that research produced the first scientific paper to warn that polar bears were especially vulnerable to climate change. Since the bears were already suffering health problems because of PCB contamination that concentrated as it rose in the food chain, they quickly became the Arctic equivalent of the caged canary used by miners to detect danger.
The key to polar bears — and the reason for their severe vulnerability to climate change — is realizing that they have spent more than 200,000 years evolving from land bears to living on sea ice and adapting to the killing of seals. The bears can readily kill the seals only when both are on the ice. When there is open water for seals, the bears are largely on a starvation diet that can, in some places, last from late June until March the following year.
"Right now is when the bears make their bread and butter, from now until the ice breaks up," Derocher says.
This is prime killing time because female ring seals are giving birth in hollows dug in the snow underneath pressure ridges that criss-cross the ice. The pressure ridges are effectively frozen rubble, the product of sheets of ice rubbing against one another, almost like the grinding of tectonic plates that produces earthquakes.
Ring seals deliberately choose this rubble
as a location for a haul-out hole in the ice since winds will usually mound the
Except that the polar bears have got the seal's birthing behaviour down pat. Even through thick snow they can detect the seal's strong odour and, possibly, hear the mother and pups.
"They rear up on their hind legs and pound down on the snow over the seal den, with their two front paws close together," Derocher explains.
"They're trying to collapse the snow layer onto the pups. Then, they dig down to the bodies. I've seen a polar bear kill 10 seal pups in a stretch of a few kilometres. The pups are small right now, a little like a soft cookie. Sometime the bears just take one bite and leave the rest. The mother is the real bonus if they can also trap her."
|
`Polar bears are a lot more social than people give them credit
for' Andy Derocher, wildlife biologist |
When the mother seal scampers, the polar
bear will sometimes use its body to plug the hole that it excavated in the snow
hummock. Having thus cut off the daylight, the bear waits with its snout near
the hole for the mother to return and check on her offspring. When the mother
seal surfaces, the lunging bear shoves its long narrow
head right down the breathing hole, with fatal results for the seal.
That's a variation of the "lying still hunting" technique that polar bears use out on sea ice.
Now that the sun is back and the air is warming here, seals are hauling themselves out onto the ice surface. The polar bears sniff for the freshest aromas at haul-out holes and use the terrain and their stealth and camouflage to get close. Then they wait.
"They are consummate hunters in terms of patience. You'd swear that they were asleep, until the seal comes up," Derocher says.
Seals aren't the only animal stalked by the perpetually curious polar bears. Humans are stalked as well, as Iacozza found out on a field trip.
"We never saw the bear but we crossed
the paw prints that circled around us. You have this sense that something is
watching you, and it's not very pleasant," says Iacozza,
33, who, in addition to his doctoral studies, is a geography instructor at the
Iacozza, Derocher and
They'll have a more accurate count by 2006, after three years of what's called a "mark and recapture" study. That means darting about 200 bears a year, marking them with a black splotch, noting age and general condition and then getting away before the tranquilizer wears off. Then, they'll dart another couple of hundred bears the next year. Some will be ones marked the first year. Then, repeat for a third year. With the percentage of recapture in the second and third years, plus estimates of births and deaths, a formula gives a good idea of the total population.
While the adult bears are tranquilized, Derocher and
The helicopter isn't powerful enough to hoist the bears for weighing but past records of size and fat thickness allow an indirect weight calculation. If there are cubs, they usually stay with their sedated mother long enough for the biologists to cast a rope around their torsos so they don't scamper off.
While the bear population is looking healthy now, Derocher is concerned about the future, especially with the latest projections by NASA that climate change by mid-century could cause the polar sea ice to shift 400 kilometres farther north in the summer. The bears must move north with the ice to avoid being stranded on land and to begin hunting seals as soon as the pack ice extends southward again in the winter.
"What you're expecting a bear to do is walk anywhere from 800 kilometres to 2,000 kilometres more every summer. Where is that extra energy going to come from?" Derocher wonders. "It's probably going to have to come from energy that now goes into reproduction."
With a shorter winter ice cover at the southern part of the range, the polar bears will also have less time to store up fat from the seal smorgasbord for that summer starvation period when they can expend 800 grams of body fat a day.
"The seals are their fat bank account and they'll have to stretch that account for another two weeks," Derocher says.
That's the biological side. Iacozza is trying to get a handle on the physical side, linking the bear's chances for survival to snow and ice characteristics that eventually will be surveyed by satellites. For starters, however, these measurements are being made from a Coast Guard helicopter that skims across the icy expanse less than five metres above the surface.
A Pinocchio-like nose called an Ice Pic juts from the front of the helicopter, providing
continuous readings of the thickness of the ice and snow below. Scott Holladay,
a geophysicist with Geosensors Inc. of
Meanwhile, Iacozza babysits a laser altimeter that can measure undulations in the surface of only a centimetre as well as a digital video camera constantly snapping high-resolution images of the surface.
Using the digital photos and global positioning satellites, Iacozza later returns in the helicopter to within a few metres of a previous aerial track to land and measure actual snow depth at one-metre intervals along a 300 metre stretch. The final piece of information is satellite tracking of polar bears fitted with radio collars.
Says Iacozza: "You can't collar bears forever. Eventually we have to be able to say where they are most likely to be, even with changing climate, so we can control visitors or establish new parks.
"You put a satellite image in front of me and I also have temperature and precipitation information and I should be able to say these are the areas with ice and snow conditions where we would expect to find bears. This is where they would be hunting. This is where they would be mating. This is where the females would be denning."
Yet even such pioneering research may not be enough to save the polar bear across much of the Canadian Arctic if the climate modellers are anywhere near right in their projections, says a gloomy Derocher.
"As the sea ice goes, so goes the polar bear. If you're going to lose the sea ice, you can't expect the polar bear to instantly change colour back to black and start to eat berries and roots."
Additional articles by Peter Calamai
Cool
jobs, and all for science
Scuba divers gather samples
under ice
Play key role in study of Arctic ecology
PETER
CALAMAI
SCIENCE
REPORTER
ABOARD CCGS AMUNDSEN—Tethered by a lifeline and carrying a second air tank for
safety, diver Jeremy Stewart skims through the freezing waters of the
The 27-year-old scuba diver plays a vital role in a $66 million, multi-year research program — the Canadian Arctic Shelf Exchange Study — to investigate the ecology of the region and forecast the impact of climate change in the Canadian Arctic. The mission runs until 2007.
Stewart was catching small shrimp-like creatures, amphipods, sought by scientists on the research icebreaker Amundsen to help decipher the complex food chain of ice-covered waters.
But the two-centimetre-long Themisto libellula had largely evaded capture in nets lowered through a "moon pool" opening at the bow end of the ship's hull; three weeks work yielded fewer than two dozen and researchers needed hundreds of the creatures.
Wielding a dollar-store net, Stewart bagged 10 of the reddish squirmers after just five minutes, a result that prompted marine biologist Anna Prokopowicz to clap her hands in delight.
This success is just one way Stewart and
fellow diver Wayne Smith are advancing the ambitious mission that has attracted
a changing cast of 45 researchers from
"Using divers is a bit of an experiment for some of these scientists and I'm hoping that the underwater science pays off," says Stewart.
Carrying out experiments under Arctic ice is far removed from the divers' regular daily routine.
Smith, 45, is a letter carrier in
Entering his final year of commerce studies
at the
Both began diving in their teens, are qualified recreational instructors and find diving under ice challenging and exhilarating in equal parts, including the curious ring seals that often nibble at their fins.
"When you see a seal chewing away at a two-by-four that we've frozen through the ice, you know that they like to give their teeth a workout," says Smith.
|
Arctic scuba divers share workspace under ice with curious ring seals |
The seals would only present a real danger
if several decided to frolic in the diving hole — like they regularly do in the
ship's moon pool — when the divers were trying to come out, chilled and spent
after 50 to 55 minutes in the minus 1.5 C water.
The divers are prepared to go as deep as 30 metres if science demands, but so far they haven't needed to go deeper than 12 metres.
"We stay fairly close to the under-surface of the ice. That's where the beauty is as far as photography is concerned and that's mostly where the scientists want us to work," says Stewart.
The work has been eased by the enthusiastic support of Amundsen's crew, who built a wooden floor on the ice around the diving hole and erected a heated tent for protection against howling polar winds.
For the past two weeks, the divers have been:
Filling dozens of small syringes with water from just below the ice
surface. The water is then analyzed for contaminants like mercury,
nutrient content and chemical fingerprints that reveal its origin.
Catching
ice cores pushed through from above in plastic bags. Researchers hope this
backward approach will clear up puzzling shifts in the brine content of ice
cores extracted by a more conventional pull-up method.
Positioning
an ultra-sensitive light meter to measure how much of the sun's
rays warm the ice rather than passthrough to trigger
photosynthesis in algae and plankton.
These readings are vital to Jens Ehns, a Finnish ice researcher working on his PhD at the
Without the divers, his work "wouldn't have been as accurate ... and nowhere near as fast," said Ehns.
Smith and Stewart have a second goal under the Arctic ice — taking photographs and video to show others the research and the crucial role of the high-tech modifications to the icebreaker, originally launched 25 years ago as the Sir John Franklin.
The Amundsen will be used, starting in August, to support ArcticNet, a consortium of northern researchers from universities and government agencies in eight provinces and the four territories investigating climate change.
Additional articles by Peter Calamai
How
Arctic diapers saved the day
Handlebar
grips also useful when studying plankton Researchers must improvise a bit
aboard icebreaker
PETER
CALAMAI
SCIENCE
WRITER
ABOARD CCGS AMUNDSEN—Although he's only 5 years old, Conrad Trela
has already made a crucial contribution to pioneering research about underwater
life in the frigid Arctic Ocean.
Or more accurately, his long-unneeded disposable diapers have.
If Conrad's father, Piotr
Trela, hadn't stuffed several of those diapers into a
vulnerable part of a special underwater camera, a unique experiment probably
would not be taking place now aboard
The diapers soaked up traces of sea water seeping into the battery compartment as the camera, called a plankton video recorder, was winched more than 200 metres to the bottom of Franklin Bay in the western Arctic, where the Amundsen has been frozen into the ice since November.
"The pressure was bending the canister that holds the gel-pack batteries and sometimes a little water would get in," explains Trela. "If that got on the wires, it would short out the batteries for sure and maybe even zap my camera."
Before the Amundsen's mission winds up in September, that camera will have taken between 50,000 and 100,000 candid snapshots of the myriad underwater denizens that are part of a thriving web of life in an ocean once thought to be largely dormant under a thick ice cover.
The story of Trela's video recorder exemplifies the difference between the chaotic make-do reality of scientific investigation in the field and the sanitized version presented in conferences and academic articles.
And the diapers are just one of many examples of ingenuity and improvisation by the four dozen researchers who use this vessel as a base for six weeks at a stretch, cut off from their normal channels of supplying and repairing equipment.
The saga began last year at
"This is the Honda Civic version," proudly proclaims the gangly and affable 44-year-old.
Although these specialized cameras began
cropping up in ocean research a decade ago, they have never been used
extensively in the
Diaphanous creatures normally squashed into goo by the mesh of nets — the Old Faithfuls of ocean biology — can be captured on video in all their delicate beauty. With a picture transmitted every 10 or 20 centimetres, depending on winch speed, the camera also divides the water column into much thinner slices than nets do, letting scientists measure small-scale changes in light levels or the makeup of marine life.
As the name implies, these cameras are primarily intended to photograph the two basic varieties of plankton — phytoplankton, which makes its own carbon through photosynthesis, just as grass does; and zooplankton, which acquires carbon by eating other organisms.
Each category is further subdivided into a bewildering array of creatures seldom more than two centimetres long and often mere millimetres in length.
There are holographic versions of plankton video recorders that produce three-dimensional images and sleek commercial models in which the digitized images are pre-sorted by proprietary software.
And then there's Trela's model, which is neither sleek nor digital. His video camera and recorder come from an industrial security system. The strobe light is the handheld kind used in factories to measure how fast a machine is turning. Memorial's machine shop fashioned the hefty metal frame.
Trela's son and 10-year-old daughter, Olga, contributed other vital protection from electrical short-circuits. The rubber tubes covering two crucial connections are actually handgrips from children's bicycles, made waterproof with epoxy cement.
With a big dent in one side, where the frame lost an argument with a ship bulkhead, this homemade plankton video recorder might be laughable — except for one thing: It works.
Which is more than can be said for the sleek commercial version, with its onboard computer boasting 27 gigabytes of memory, which was part of the $9 million worth of instruments loaded on to the ship. It developed software hiccups on the second leg of the voyage and now sits forlornly in a corner.
"They didn't want me to bring mine because they had this brand-new recorder on board," says Trela. "But if I'd had to depend on the ship's apparatus, I would have been left sitting here, doing other people's research."
The Memorial researcher didn't know for sure that his homemade recorder would work in the deeper parts of the Arctic Ocean because there had been time for only one rushed trial in the relatively shallow waters of Conception Bay. More importantly, he didn't know if there was going to be much underwater life that it could photograph.
"We turned it on for the first time and there were images everywhere," he says. "We were pretty excited."
After four months aboard the ship, often making underwater recordings twice a day, Trela still radiates excitement as he points out grainy white flashes on the video monitor.
"That's a medusa, the thing that looks like a jester's cap. There's a sea arrow, a chaetognath. It's a predator. Those are ctenophores, which just become goo in a net. And that's an appendicularian, which we call appis for short."
He also has some UUOs on tape, Unidentified Underwater Objects, but says it is far too soon to speculate whether the plankton recorder might provide the first inkling of a species previously unknown to science. Any such finding would require confirmation by actually trapping the creature.
"It's good to work on a ship with so many other researchers because we can compare data to help understand the bigger picture, the context," Trela says.
The bigger picture here is understanding the fallout from the thinning of sea ice in the Canadian Arctic by examining what's happening in detail along the narrow continental shelf where the Mackenzie River annually dumps an immense load of sediment and freshwater.
This Canadian Arctic Shelf Exchange Study
(CASES) dovetails with an even more ambitious project called ArcticNet, which will try to unravel the potential impact
of climate change across the entire
Federal agencies have pledged $66 million to support this research until at least 2008, with $30 million earmarked for refurbishing and outfitting the Amundsen for its research role.
But the planners didn't think of everything. Piotr Trela has already e-mailed home for another batch of disposable diapers.
Additional articles by Peter Calamai