Arctic fox seem to make their living by following bears around and scavenging. We have seen foxes trailing behind bears as they travel, and their tracks often wind around bear prints. (My apologies that the pictures below are graphic. However, the carcass below illustrates a critical aspect of the life of predators).

These bones – the vertebral column and attached ribs – are all that remained of a large seal that was most likely killed by a polar bear. The area was covered with fox tracks, and the carcass had been thoroughly scavenged.

Even a flipper had been used for food – the bones of this flipper were intact, showing the similarity to the shape of my hand.

Such an existence seems precarious; polar bears range over great distances, and their successful hunts are few and far between. What if the fox doesn’t find a carcass? It turns out that foxes themselves can be successful predators of young seals. In the early 1970s, a researcher named Thomas Smith trained his Labrador dog to sniff out seal lairs (lairs are in hollow spaces on top of sea ice but below a blanket of snow; seals use these protected spaces to rest and give birth). He spent several winters digging up hundreds of lairs and found evidence that Arctic foxes were able to enter the lairs and predate on young seals. He wrote:

“A keenly developed olfactory sense allows the arctic fox to locate the subnivean seal lair, sometimes through snow depths of over 150 cm…Lairs that had been entered by foxes showed one or more entry holes. Usually the holes penetrated the lair at a slight angle and were never more than 20 cm in diameter…In the case of an apparently successful kill, blood was always present on the floor of the birth lair once the lair had been dug open…When the lair was well developed into a tunneled structure there was usually more blood and the site of the actual kill usually appeared to be in one of the small tunnels”

In fact, Smith concluded that in certain parts of the Arctic, foxes may be more important predators of young seals than bears. However, foxes were never found to kill adult seals, which must be simply too large for a fox to attack. Foxes were also more thorough than bears. They seemed to remain at the site for several days and consume the entire carcass.

So perhaps foxes don’t live as close to the edge as I originally thought, although no animal in the Arctic seems to have it easy. In a very different way, our field season is currently on the edge – due to good weather early on, we flew for more hours than were budgeted, leaving one of our two helicopters in a crunch for funding. We have scrambled to line up addition funding, to support the helicopter for more time; otherwise, we could be forced to end the season in just a couple days. We have had some tremendous luck in locating and re-sampling bears from previous field seasons, giving us great data on how bears fare over time – I really hope we are able to continue flying.

On what has become a rare, sunny day, this is my view through the bubble windshield of the helicopter, wrapping below my feet, as we fly north over the sea ice.

Thomas Smith’s article:
Thomas G Smith. 1976. Predation of ringed seal pups (Phoca hispida) by the arctic fox (Alopex lagopus). Canadian Journal of Zoology, Volume 54, pages 1610-1616.

The three types of killer whales. From R. Pitman, P. Ensor, J. Cetacean Res Manage 5(2):2003.

Ross Sea killer whales appear in the McMurdo Sound area and the southern Ross Sea, in early December and ply various fast ice edges (ice attached to the land), which as the season progresses recede further and further south toward the continent. They also apparently forage under or along the edge of the Ross Ice Shelf by Cape Crozier on the other side of Ross Island. These whales feed on fish that live under the fast ice and as the ice recedes the whales are able to exploit more and more feeding territory. Sightings of these whales, from land, helicopters and ships have been carried out through the years, most recently from the Cape Crozier and Cape Royds penguin colonies on Ross Island, where it has been noticed that the presence of whales (including minke whales) follows a shift in the diet of the penguins.

Killer whales foraging in a sea ice crack.

In 2005 the ratio of C to B killer whales was 50-1, but over the next few years it steadily dropped to 16-1 by 2008. As the observed numbers of B whales (seal eaters) did not change during this time, the altered ratio was due to the decrease in Ross Sea killer whales. During the years of these observations another important series of events was taking place.

Although commercial fishing of the Antarctic toothfish (sold as “Chilean sea bass”) in the Ross Sea began in 1996, it was expanded in 2004 from 9 to 22 fishing vessels; not surprisingly that same year the catch reached its allowed limit of 3500 tones. These boats target the largest adult toothfish, which is the same size those taken by the whales. Toothfish are a slow growing species which do not reach maturity until 16 years old. Many of these fish taken in the fishery were over 25 years old, some older.

Antarctic toothfish.

Since 2004, the commercial catch has remained steady year by year. Catch and release efforts of toothfish by scientists in McMurdo Sound remained steady from the years 1974 to 2000, but dropped 50% in 2001 a few years after the commercial fishing began and then to 4% in 2007, only 3 years after the peak commercial catches began. It would appear that the drop in Ross Sea killer whale numbers is related to the increase in the commercial fishing of the toothfish.

Are there any other animals that would be affected by the reduction in toothfish numbers?

Weddell seals also take toothfish as a primary food source and their numbers have not decreased in McMurdo Sound, though trends elsewhere along Victoria Land are unknown. Seals are able to dive deeper and stay under longer than the whales and therefore able to catch the fish which are safe from the whales. Seals therefore not only forage where the whales forage, but also in areas the whales can not reach, places covered with extensive fast ice where small cracks provide breathing holes. Seals also eat silverfish. It is thought that whales also eat silverfish but there are no confirmed sightings for this. The whales therefore may be more sensitive to changes in toothfish availability. If the toothfish industry continues to extract the current yearly numbers, it is predicted these creatures will decline more rapidly.

For more information about the Ross Sea, the toothfish industry and how it is affecting penguins, whales and seals go to The Last Ocean.

For some time it was thought that Weddell seals did not eat the toothfish and therefore would not be affected by the reduction of these fish in the ocean. The fishing industry has pushed to increase catch limits based on this assumption. We’re learning, though, that this is not true by indirect means.

One way researchers determine what an animal eats is by sorting through their scats (body waste). Indigestible parts pass through the body of seals and whales and can be identified. In the case of fish, the ear bones, or otoliths, are used to determine not only what species of fish are eaten, but how old and large they are. Toothfish otoliths have not been found in seal waste. But recently we’ve learned why.

Antarctic Toothfish ear bone (otolith).

As is the case with many discoveries chance plays a large part. While out on a diving expedition one researcher discovered the heads of many toothfish near a crack in the ice. The only predators in the area are seals, so these heads must be the remains of their meal. No wonder there are no otoliths in the seal waste, they don’t eat the heads! By observing seals in holes drilled through the ice for scuba access, it has been observed that seals remove the heads so this information was already known. But many people still doubt the implications of this or contend that it is a ‘local’ phenomenon. Finding these heads, in the company of seal holes, was another clear indication that this belief is wrong. Retrieving these heads would also mean that scientists could remove the ear bones (otoliths) and determine the age of the fish as well as where the fish grew up (one of the many mysteries about toothfish that remains unsolved).

The crack, where seals come to find toothfish hiding under the ice.

The helicopter landed us in this remote place on the McMurdo ice shelf.

So off we go. First a helicopter ride to the place where the fish heads were first found, and then a 10 km walk over and around the rough terrain along the crack in search of other evidence. All in all the remains of 30 fish were found, and 20 heads were brought back to the lab to extract the otoliths.

Antarctic toothfish heads, the remains of a Weddell seal feast.

Searching for Antarctic Toothfish heads on the McMurdo Ice Shelf crack.

Bagging Antarctic Toothfish heads.

As it turned out, most of the heads had become mummified, i.e. freeze-dried, and acidic action in the flesh during the process of decomposition in many cases dissolved the otoliths. There were just little ‘puffs’ of white stuff where the otoliths should have been. Skuas had eaten the otoliths in other of the heads. But, we did find otoliths in 6 heads, and these will be tested and analyzed in a lab in the US. Providing evidence to fishery biologists that toothfish are an important food source for seals will help the argument to limit the commercial catch.

Learn more about Antarctica toothfish and conserving the Ross Sea for all marine organisms by visiting The Last Ocean.

Temperatures climbed into the 30s and 40s (Fahrenheit) and the skies continued to clear, allowing us several long days of excellent flying. Tracking conditions had been poor because sunlight becomes quite flat with low overcast skies, making it difficult to see tracks. Clear skies and direct sunlight made tracks easier to see. However, after several days the warm temperatures began to melt out all tracks, making it difficult to distinguish fresh tracks from new tracks.

Following a trail of polar bear tracks on the sea ice. To find bears for capture, we fly low over good habitat – areas of sea ice with cracks and leads which allow seals to surface, making them vulnerable to predation – and look for bears or their sign. In good light conditions such as this photo, tracks are easy to see. These tracks belonged to an adult female with two cubs-of-the-year (COYs).

We captured several sows with cubs, and an adult female and an adult male that were most likely a breeding pair. As we have all season, we fitted some of these bears with GPS collars which periodically record time, date, location, ambient temperature, bear activity, and salt water immersion (as a record of swimming). This data is stored on the collar and it is transmitted to satellite twice per day, allowing us to track the bear in real-time. We will use these collars to locate bears for recapture in the fall. For the possibility that we may not be able to recapture some bears, the collars are programmed to release in November and fall off the animal.

An adult male bear, positioned on the pads used for BIA, with the mask and bag used for breath collection.

An adult female laying on her side with her cub against her chest.

During this last week, I thought about how brutal this environment would be for any living thing that was not prepared. The sea ice and tundra is a beautiful, intriguing area, and I really enjoy spending time here. However, I know I am out of place. For example, I usually carry some kind of emergency fire-starter while doing field work (thankfully, I have not used it). But here, there is almost nothing to burn – some driftwood pokes out of the snow along the coast, but there is nothing on the sea ice. I enjoy cold, snowy regions and I have spent a lot of time doing winter field work and skiing, and the Arctic is quite different than anywhere else I have been. The environment makes the cultures which have thrived up here all the more interesting.

Sea ice breakup continued. One day we flew about 140 miles northeast of Deadhorse to look for bears and on the return flight, we encountered a new lead of open water that looked to be over a mile wide – it had opened that afternoon. Our pilot calculated the ice in the area was moving about a third of a mile per hour.

We counted nearly 100 seals along a single crack in the ice; 10 are pictured here. They hauled out through the crack onto the sea ice to rest and breathe. Seals do not stray far from their holes; if a polar bear approaches they can quickly escape back into the water.

Our last flight day arrived quickly. We flew in the morning but did not find any bears, then returned to Deadhorse to begin packing up. For over a month, I had woken up every day prepared to fly and to work with polar bears and it was surprising how quickly everything changed. We broke down all of the lab equipment, packed it into crates, and cleaned the living space. Over three days our research team departed on the daily flights to Anchorage. I was the last to leave on Friday evening, turning down the heat in the living space, turning off the lights, and locking the doors behind me.

I landed in Anchorage for an overnight layover and it felt like stepping into a different world. The northern coast of Alaska is treeless and it was still coated with ice and snow, while Anchorage, on the south-central coast, seemed to be teeming with green trees and summer warmth. From Anchorage, I flew to Seattle then Denver, took a bus to Fort Collins, and finally got a ride to Laramie. I am glad to be home.

The sun will be above the horizon in Deadhorse until late July. One day last week we flew all day and had several captures. I finished my labwork at about 2am and I took this picture (without using a flash) of Deadhorse as I left the lab. This twilight is as dark as it got, and by mid-summer the skies will be bright through the night.

For field work, we have very nice accommodations here in Deadhorse including occasional meals at one of the hotels in town. Polar bears do not have the luxury of eating regularly – sometimes they must go for days or even weeks and months without having the opportunity to kill a seal for food.

Site of a seal kill by polar bears, probably a sow and cub we spotted nearby that afternoon. Seals – here, likely ringed seals (Phoca hispida) – maintain lairs carved out in snow drifts on the sea ice, in which females give birth and nurse their young. The lair is over a hole in the ice, allowing the seals to come and go without being seen. Polar bears seek out lairs and pounce through the snow roof to catch the seals inside – this likely created the hole in the center of the photo. We hovered about fifteen feet above the site for this photo.

Polar bears specialize in hunting seals and seals provide most, if not all, of the polar bear diet. During summer, some bears remain on shore as the sea ice retreats far north; seals are typically not available for hunting on shore during summer, so these bears probably have little to eat. Some bears follow the retreating sea ice north; however, if the sea ice retreats too far north (as has happened in recent years) it moves beyond productive near-shore waters where it is thought that seals congregate. In that situation bears spending the summer on the sea ice may find little to eat as well.

To find out if bears are getting by without food during the summer, we are taking samples indicative of fed status for bears on shore and those on ice. One sample is exhaled breath. Once the bear is anesthetized, we place a mask over its snout; the mask is connected to a two-way valve and the exhaled air fills a collection bag. Usually it takes less than a minute for the bear to fill the bag.

The mask and two-way valve at the right, connected the collection bag at the left.

One analysis estimates how much of the carbon in the exhaled carbon dioxide is actually carbon-thirteen (13C). This is a stable isotope of carbon; unlike a radioactive isotope, it does not readily break down (thus the term “stable” isotope). 13C is slightly heavier than regular carbon and is present in small amounts in most things. The carbon in exhaled carbon dioxide comes from digested food – and, the amount of 13C in carbon dioxide will be slightly different if a polar bear is breaking down its own fat stores for energy than if a polar bear is digesting a seal it has killed. Once our collection bag is full of exhaled breath, we take a small sample of the breath and inject it into an airtight container for stable isotope analysis back at the University of Wyoming.

Another site of a seal kill by a polar bear. Nearby we caught a 940 lb male.

A back paw of the male captured near the seal kill, with a glove for perspective. We had to move quickly to finish this capture and fly back to Deadhorse because a snowstorm moved in and we were losing visibility fast.

Canada Glacier with frozen Lake Hoare in the background.

Summer melting from the Canada Glacier feeds a stream that flows into Lake Hoare.

The Dry Valleys are dry because very little snow falls here, the average water content is less than a centimeter. Yet a fully functioning ecosystem exists here, in the ice-covered lakes and the soils of the valley floor. Even though the ecosystem is all but invisible to the naked eye, it still has a basic food web: primary producers (mats of moss and algae in the lakes, bacteria, yeast, fungi and other microbial life in the soils ), grazers (microscopic invertebrates called rotifers and tardigrades), with the top of the food chain consisting of tiny nematode worms. Curiously, there are no known predators in the Dry Valleys soils. These valleys constitute a Long-Range Ecological Research (LTER) study site and represent what scientists believe might be a model for life on Mars if it exists.

Lisa Strong on a hike with Canada Glacier behind her.

The origins of Seuss Glacier pouring through a mountain pass in the Dry Valleys.

Lisa and I went for a walk up the Taylor Valley to see whether we could uncover any evidence of life and saw little, except for a couple of long-dead seal mummies (why they traveled so far from the sea ice is anyone’s guess) and some algae-covered rocks and brown floating scum, looking for all the world like whipped chocolate mousse. We did see plenty of wind-scoured rocks and glaciers pouring through gaps in the surrounding mountains.

Bones and skin of a seal mummy that perished hundreds or thousands of years ago.

Biological scum on Lake Chad.

For easier walking, I tried to cross the moat between land and solid (white) lake ice. What I thought was thick ice wasn’t and I broke through up to my knees for my own version of the polar plunge. After changing into dry pants and socks, we continued on our walk but the only macroscopic life we saw was a lone skua winging up the valley.

Mary after breaking through lake ice.

I knew I needed to dig deeper, so I’ll turn to the LTER scientists studying the different parts of this ecosystem from the glaciers that feed life-giving water to the lakes and soils, to the ice-covered lake waters that support microbial life, to the soils that provide habitat to bacteria, yeast and fungi, and invertebrate creatures that make up “charasmatic megafauna” of the Dry Valleys. Look for upcoming video interviews with these LTER scientists.

Glaciologist Hassan Basagic of Portland State University explaining the dynamic of Canada Glacier to Lisa.

MCMURDO STATION, ANTARCTICA– In our webcast with John Weller recently, he showed some photos of a group of bat stars and close-up of the top of one of them. Bat stars are common sights on the bottom of Antarctic seas, clustering under holes and cracks in the ice where seals congregate. They scavenge seal droppings or bits of food left over from the seal’s fishy meals; nothing in the ocean goes to waste.

Photo (c) John Weller.

We were curious about the structures on the back of the little bat star (also known as a cushion star) so I wrote to my former advisor at U.C. Santa Cruz, John Pearse. Dr. Pearse did his doctorate scientific research in Antarctica on these invertebrate creatures whose scientific name is Odontaster validus. He emailed me back the other day and explained what was on the upper surface of the cushion star.

Photo (c) John Weller.

The pink flower-like structures are called paxillae and they create a space for water to circulate across the surface of the stars making it easier to absorb oxygen from the water. The purplish bud-like structures are called papulae, or “skin gills.” They extend from the inside of the star’s body cavity and have lots of tiny beating hairs, called cilia, that also help the animal absorb oxygen and get rid of waste products.

It’s curious that in such richly oxygenated water as found in the Ross Sea, these animals need two structures to aid their respiration. Dr. Pearse notes that there’s probably an interesting story there for some future invertebrate zoologist in Antarctica to investigate.

Is there hope for Polar Bears? Just ask the experts.

Polar bears have become the icon of climate change, stirring people’s emotions and bringing awareness to the issue in an unprecedented manner. And yet, both in the scientific research community and the media there is disagreement and discrepancies over what the real impacts of climate change on polar bears are. As of yet, there are no studies that span the entire Arctic region and all polar bear populations. Also, there are no models that fully look at the relationship between polar bear dynamics and climate.

What does the future hold for polar bears?

S.J. O’Neill from the Tyndall Centre for Climate Change Research, School of Environmental Sciences, University of East Anglia, UK, and others proposed a unique solution to finding out how polar bears are doing Arctic wide. They gathered polar bear experts worldwide and gave them an anonymous survey that asked detailed questions regarding polar bear populations and modeled sea-ice data. Their goal was to tease out where the discrepancies lay between experts and what experts really thought the future held for these amazing animals.

As it turns out, the discrepancies are few and the dramatic pictures of polar bears in an ice-free sea reveal some truth. Ninety percent of experts agree there will be a substantial decline in polar bear habitat and their populations across the entire Arctic. Sadly, even if significant conservation measure were put in place, experts agreed there is little prospect of preventing significant population declines. The populations in the Barents Sea, Chukchi Sea, and Hudson Bay were considered the highest risk.

A polar bear coming out of water onto ice floe.

The primary danger posed by global warming is malnutrition and starvation due to sea-ice habitat loss. Polar bears travel far from shore hunting for seals and other marine mammals. They spend much of their life on the sea-ice using it as both a platform for resting and their hunting grounds. The reduction in sea-ice forces bears to swim farther and farther distances, depleting their energy and occasionally leading to drowning. Also, due to rising temperatures, sea-ice now melts earlier in the year, driving the bears back to shore before they have had sufficient to build fat stores. The result is polar bear populations that are undernourished, have low reproductive rates, and lower survival rates. Let’s hope those polar bear experts get together and find some solutions, and fast.

A polar bear mother and cub.

A crabeater seal resting.

Crabeater Seals

A crabeater seal pup.

A crabeater seal with bite wounds.

Found amid the pack ice during the Antarctic spring and summer, crabeaters primarily hunt krill—not crabs. They’re filter feeders, like many whales, but instead of baleen plates to trap the krill, they have extraordinarily complex teeth that do the job for them. They swim open-mouthed through a school of krill, sucking in water along with the tiny crustaceans. Then they close their teeth together, trapping their prey, while deep spaces in their teeth let the water out. They feed mostly at night, diving continually for many hours, and can reach a depth of about 100 feet (30 m). Pups are born in the spring and are weaned in just three weeks. After that they’re left to forage on their own.

As winter approaches, the crabeaters head for lower latitudes. They’re seen as far north as the southern coasts of South America, Africa, and Australia.

Crabeater pups are preyed on by leopard seals, and many adults have parallel scars that attest to an encounter with a leopard seal in their youth. The adults weigh about 440 to 660 pounds (200 to 300 kg) and usually aren’t bothered by the leopards. But they’re no match for the type B orcas that dine on both seals and penguins.

The crabeater is the most abundant seal species in the Southern Ocean. Their population size isn’t known with any precision, but it’s thought that they number in the millions. The decline of the baleen whales has left more krill for them to feed on and has probably led to an increase in their numbers.

Weddell Seals

A Weddell seal pup. Photo copyright John Weller.

Although they’re large animals, weighing in at about 1,000 pounds (455 kg), the Weddell seals are regarded as downright cute. Adjectives such as “appealing” and “smiling” are often applied.

These seals, named for nineteenth-century British explorer James Weddell, are year-round inhabitants of the fast ice that surrounds the Antarctic coast, spending much of their time below the ice. They dive through breathing holes to hunt, and they’ve developed some interesting strategies for doing so. They dive deeply, then turn upward to find fish backlit above them. They also blow into cracks in the ice, which startles fish into leaving their safe havens. We know about these hunting techniques from videos taken by the seals themselves via small cameras attached to their heads by researchers. Their penchant for hunting under the fast ice offers good protection from their main predators, orcas and leopard seals, who can’t reach them there.

A Weddell seal under a hole in the ice. Photo copyright John Weller.

A Weddell seal under a hole in the ice. Photo copyright John Weller.

During the cold Antarctic winter, the Weddells keep their breathing holes open by chewing at the ice, although this activity takes its toll on their teeth, which may ultimately shorten their lives. They may use tidal cues to determine good times to hunt, but how they find their prey or navigate back to their breathing holes in the dark is a mystery.

In September and October, pups are born on the fast ice near all-important breathing holes. When they’re a week old, pups start learning to swim and to haul themselves out onto the ice. They’re weaned at six weeks, after which they hunt on their own.

Weddell seals mainly eat fish. Among their favorites are the Antarctic toothfish—which makes its way to market as the Chilean sea bass—and the Antarctic silverfish. But in the last few years a fishing industry targeting the toothfish has been established in Antarctica’s Ross Sea, the last part of the world’s ocean that has not been overfished. The toothfish competes with the seals for silverfish, so what will be the effect on the Ross Sea Weddell population as toothfish are taken by the fishery?

Biologist David Ainley wants to find out. As he wrote in a November 2007 dispatch,

The idea is that as more Chilean sea bass are taken from the Ross Sea, the seal population should change. Seal numbers would either decline because there are fewer sea bass to eat or increase because with fewer sea bass there would be more silverfish for the seals to eat.

David, along with seal researchers from Montana State University, has proposed a study to monitor the Ross Sea Weddell seal population and to determine the effects of fishing on the Ross Sea ecosystem. Currently, there are about 32,000 Ross Sea Weddels out of a total Antarctic population that’s estimated at 800,000.

Leopard Seals

Leopard seals have a lean body that’s about 10 feet (3.2 m) long and a somewhat reptilian head. Photo by Nick Russill.

A leopard seal has more in common with the cat that it’s named for than just its spots. Both are top predators that are swift, shrewd, stealthy, and strong.

During the austral summer, leopard seals are most commonly found near the edges of the Antarctic pack ice. They lie in wait just under the ice for a hapless seal pup or an unwary penguin to venture into the water, then quickly attack with their large mouths and powerful jaws. They’re also known to leap onto the ice to grab their prey and drag it into the water.

These seals can eat almost anything, and their teeth will tell you why. Their canine teeth are long and sharp like those of a cat, ideal for catching penguins and small seals. But their molars form a sieve, like the teeth of the crabeaters, so they, too, can filter krill from the sea. They also eat fish and a variety of other marine creatures, but researchers have noticed that individual leopard seals seem to have distinct food preferences, subject to availability.

A leopard seal showing its teeth. Photo by Chad Rosenthal.

The population size of the leopards may be something like 200,000, but it’s hard to make a tally of solitary seals spread throughout a vast inaccessible area. For the same reason, very little is known about their breeding behaviors or how their pups are raised.

During the winter the leopards tend to be found near the coasts of sub-Antarctic islands, with the juveniles often seen farther north. But these seals are known for their wandering ways and have been sighted near the coasts of South America and Africa, and even in the waters off Heron Island, which is at the Tropic of Capricorn.

Leopard seals are hunted by orcas, but this doesn’t threaten the species. Because they’re apex predators, the future health of the leopards will probably be determined by the general health of the Antarctic ecosystem.

Yvon Csonka, a professor at the University of Greenland and president of the International Arctic Social Sciences Association (IASSA), gave one of the Plenary Keynote talks on “Polar Societies and Cultures in a Changing World.” Among the variety of challenges facing polar societies mentioned by Csonka, is the melting permafrost and its effect on people who have been surviving in the Arctic for millennia. Csonka described small communities that have already been forced to leave their villages due to erosion caused by melting permafrost and because of a lack of sea-ice in summer. Csonka said currently these moves “Are not common, but will happen more and more in the future.”

Later, I pulled Csonka aside for a few minutes, and he elaborated on how climate change will affect people’s access to resources, especially animals like seals and caribou, which local people depend on for sustenance. Reductions in sea-ice have been devastating to seal populations since they require the ice for both birthing and weaning. When mother seals can’t find sea-ice, they are forced to give birth in the water and the pups drown. Even if they find ice to birth on, the sea-ice has been breaking up too fast and the pups don’t have time to wean before they are subjected to the freezing waters.

A young spotted seal.

The changing climate has caused serious problems for Caribou populations who require specific snow thickness and type of snow. “When the snow layer is thin and dry, Caribou can scrape at the snow to get to the lichen underneath,” Csonka said. “But, with increased precipitation-from climate change-there is an increase in snow and its wetter creating deadly conditions for caribou since the upper crust becomes too thick for the caribou to break through.” Despite these drastic problems, Csonka is hopeful that Arctic communities will successfully adapt to climate change, since they have been doing so for millennia.

Caribou on the tundra.

Stay tuned in the next few days to learn in more detail just how people, animals and the environment will cope and adapt in a changing polar environment.