AMUNDSEN GULF, NWT -- After chainsawing through solid ice, lowering 350 metres of fishing line and exposing themselves to a -35 windchill for several hours, Louis Letourneau and Alexis Burt seem surprisingly happy to haul up a few cupfuls of inedible crustaceans.
Unlike the world's increasingly desperate commercial fishermen, Letourneau and Burt are not trying to exploit the Arctic waters for some new and tasty underwater foodstuff. The Laval University research technician and the University of Manitoba masters student are trying to gather up zooplankton -- that is, tiny free-floating animals -- in an effort to figure out what's going on beneath the ice of Canada's remote Amundsen Gulf.
Researcher Louis Letourneau pulls up a net that gathered zooplankton.
For years, biologists believed life in the northern seas stood relatively dormant most of the winter, when ice covers the polar region and light barely penetrates the depths.
But zooplankton sampling being conducted by researchers on board the Canadian Coast Guard icebreaker Amundsen is painting a much more dynamic picture of the Arctic ecosystem during the winter.
"There are many things happening. There are species reproducing during the winter," says Gérald Darnis, a Laval PhD student who's currently overseeing the zooplankton research aboard the Amundsen.
"It doesn't seem to be the way we thought it was at all."
Amundsen oceanographers have identified 49 different species of zooplankton in the Arctic system, ranging from tiny crustaceans that glow a brilliant turquoise in the dark, to arrowworms that resemble little noodles to five-centimetre-long sea slugs.
Research technician Steeve Gagne carves out hole in Amundsen Gulf.
The free-floating animals eat tiny plants and each other and are in turn consumed by larger animals such as Arctic cod, which are in turn devoured by the likes of ringed seals and beluga whales.
To get a handle on what organisms live below the ice, researchers on the Amundsen use both the ship's moon pool -- basically, a hole in the bottom of the hull -- and ice-fishing holes to lower plankton nets down to nearly the bottom of the gulf.
The moon pool is easier to use, but the top 10 metres of the water column can not be sampled, because it's too close to the ship.
Hence the need to venture out on the sea ice and use chainsaws and metal tongs to carve out a four-square-metre hole, which is a back-breaking task.
Once the hole is ready and a tripod is erected overhead, two fine-mesh nets -- each capable of capturing organisms as small as 200 and 50 microns, respectively -- are lowered below the ice, first to a depth of 10 metres, then all the way down to 350 metres. (A fine human hair is about 50 microns in diameter).
Each net has a canister on the bottom that collects the plankton caught in the nets. The first dip, collected from 10 metres, produces a single themisto libellula, a brown, fingernail-sized amphipod that wriggles like a shrimp.
Zooplankton from the Arctic sits in a lab on the Amundsen for analysis.
But the second sample is more spectacular: Dumped into a white pail, it's brimming with bright pink calanus hyperboreus, a copepod that plays a major role in the Arctic ecosystem.
These copepods are pink because the females are about to lay their eggs. The males are relatively colourless, just like their counterparts in university campus bars.
When the samples are taken on board, Darnis and his teammates from Laval will catalog the quantity of organisms, note what depth they were found and also take notice of the egg mass.
Their goal is not just to gain a better understanding of an ecosystem that is typically only studied during the ice-free summer, but to see how carbon is moving around in the ocean.
The research has profound implications for climate-change projections, as the receding summer sea ice could mean more biological activity inside the polar oceans -- and therefore more carbon dioxide coming from the animals that live in these seas.
In other words, more organisms in an increasingly ice-free Arctic Ocean could mean more greenhouse gases, warmer temperatures and then even less ice and even more organisms.
But the fact that copepods such as canalus as well as Arctic cod reproduce below the ice could mean such a feedback loop may not be so severe, if it exists at all.
"Right now, we don't really know," Darnis says. "That's why we are conducting this research."
bartley.kives@freepress.mb.ca
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