Polar Bears and Ringed Seals: A Relationship in Transition

Disconnected sea-ice during the Svalbard summer (Source: Allan Hopkins/Creative Commons).

Along the tidal glacier fronts of Svalbard, an archipelago halfway between Norway and the North Pole, polar bears have changed their hunting practices. A recent study published in the Journal of Animal Ecology indicates the new behavior is a response to rapidly disappearing sea ice. Charmain Hamilton and other researchers from the Norwegian Polar Institute mapped changes in the spatial overlap between coastal polar bears and their primary prey, ringed seals, to better understand how the bears are responding to climate change. The results don’t bode well for the long-term survival of polar bear populations: as sea ice continues to shrink in area, ringed seals—calorie-rich prey that are high in fat— have become increasingly difficult to catch during the summer and autumn. The bears are now finding sources of sustenance elsewhere: in the archipelago’s thriving bird colonies.

The Arctic is warming at a rate three times the global average, and the sea ice in the Svalbard region is experiencing a faster rate of decline than in other Arctic areas. As Charmain Hamilton reported in an interview with GlacierHub, the findings could demonstrate what the future holds for the top predator elsewhere. “The changes that we are currently seeing in Svalbard are likely to spread to other Arctic areas over the coming decades,” she said.

A polar bear steps across a gap in the sea ice near Spitsbergen, Svalbard (Source: Thomas Nilsen/The Barents Observer).

Svalbard’s polar bears exhibit one of two annual movement patterns: some follow the sea ice as it retreats northward during the summer, while others stay local, inhabiting coastal areas throughout the year. Both groups of bears depend on sea ice as a platform to hunt ringed seals. Given a rapid decline of sea-ice levels that began in 2006, Hamilton and other researchers wanted to know if the coastal bears were still hunting ringed seals under the deteriorating conditions.

The researchers compared satellite tracking data for both polar bears and ringed seals from the periods 2002-2004 and 2010-2013 to assess whether the predator-prey dynamic had shifted. The data was analyzed according to season, with researchers paying careful attention to the dynamics of spring, summer and autumn.

In spring, access to fat-rich ringed seals is critical, particularly for mothers weakened from nourishing their young in winter dens. The study shows that coastal polar bears continued to spend the same amount of time near tidal glacier fronts in spring as they did when sea ice was more abundant. The authors conclude that the declines in sea ice in Svalbard have not yet reached the stage at which bears must find alternative hunting methods during the spring. This could help to explain why cub production is not currently declining.

A calving glacier in Svalbard (Source: Geir Wing Gabrielsen/Norwegian Polar Institute).

However, during summer and autumn, bears are spending less time in the areas around tidal glacier fronts. The study shows a significant decrease in the amount of time bears spent within 5 km of glacier fronts and a sharp increase in the distances they traveled in search of food per day. The ringed seals, on the other hand, have remained near the glacier fronts. As Hamilton reported to GlacierHub, “The reduced spatial overlap between polar bears and ringed seals during the summer indicates that the reductions in sea ice have made it much more difficult for polar bears to hunt their primary prey during this season.”

As sea ice recedes, ringed seals are increasingly relying on calved pieces of glacier ice as shelters and resting places. Since these pieces of calved ice are no longer connected to land-fast ice, polar bears can no longer walk up to the seals or wait by their breathing holes, but have to attack from the water. This involves swimming surreptitiously up to seals resting on calved glacier ice and bursting onto the platform to make a kill. But this specialty hunting technique has only been observed in a minority of bears.

A Svalbard polar bear eats a ringed seal on a calved piece of glacier ice (Source: Kit Kovacs and Christian Lydersen/Norwegian Polar Institute).

So where are the coastal bears getting their calories during summer and autumn? The study shows that along with the marked decline in sea ice, the coastal bears were spending more of their time around ground-nesting bird colonies. At present, these tactics seem to be working. The bears are benefiting from a large increase in the populations of several avian species in the region, which Hamilton attributes to ongoing international conservation efforts along migration routes. While an increase in the amount of time polar bears spend on land is considered a cause of deteriorating health in other bear populations, the adult bears and cubs of Svalbard have not shown marked signs of decline.

Have the bears found a lasting alternative? Jon Aars, a research scientist and one of the co-authors on the paper, doesn’t think so. In an interview with GlacierHub, Aars emphasized that while birds and eggs provide the bears with an alternative to burning fat reserves as they wait for the sea ice to return, the dynamic is not permanent. “It is not likely that switching to eating more birds and eggs is something that can save polar bears in the long run if sea ice is gone for the whole of, or most of, the year,” he said. “We do think the bears are still dependent on seals to build up sufficient fat reserves. And it is limited how many bears can utilize a restricted source of eggs and birds on the islands.”

A mother and her cubs look out across an ice-free stretch of bay as they hunt for birds and eggs (Source: Thomas Nilsen/The Barents Observer).

The bears have adapted to the current change in their environment but may not be able to adapt as well in the future. The authors of the paper point out that the increased rates of movement required to hunt avian prey increases the bears’ energy needs. Additionally, as more bears rely on avian prey, their high rate of predation means that bird populations on the archipelago will likely decline, causing bears to alter their hunting strategies again. Ringed seals have not changed their own spatial practices, and the authors propose that more bears could learn, or be forced to learn, the aquatic hunting method.

However, ringed seal populations are in decline due to the loss of sea ice, according to Hamilton. Thus, the future of both species in the region is uncertain. In sensitive environments like the Arctic, predator-prey dynamics are fragile, particularly for species of such high trophic positions. In the future, Hamilton would like to include other Arctic marine top predators in similar studies to better understand how Arctic marine mammal communities are being impacted.

Cape Farewell and The Farewell Glacier

Artist David Buckland cares deeply for the health of the planet and believes the rest of the world should care as well. In 2001, he founded the Cape Farewell Project, an international non-profit based at the University of Arts London in Chelsea. He recently co-authored an article titled, “The Cultural Challenge of Climate Change,” along with authors Olivia Gray and Lucy Wood, which provides his reasoning for launching Cape Farewell. He hoped his nonprofit would spark a cultural reaction from artists, scientists and educators on the impacts of climate change. Cape Farewell has accomplished this goal many times over.

Beginning in 2003, Cape Farewell has invited educators, scientists and artists to voyage to the Arctic, the Scottish Islands, and the Peruvian Andes, to comment on what they see and experience. As Cape Farewell’s website highlights, “one salient image, a novel or song can speak louder than volumes of scientific data and engage the public’s imagination in an immediate way.” Cape Farewell’s ultimate goal is to elicit a human response to climate change, by engaging the public to build a more sustainable future, one that is less dependent on fossil fuels. To date, 158 artists, including film-makers, photographers, songwriters, novelists and designers have journeyed with Cape Farewell.

David Buckland deciding on the sailing route. (Source: Cape Farewell).
David Buckland deciding on the sailing route (Source: Cape Farewell).

One such artist is Nick Drake, a poet, screenwriter and playwright, who recently wrote the poem “The Farewell Glacier” in response to a 2010 Cape Farewell expedition to the Arctic. From Drake’s perspective, a more sustainable future involves taking action before this ecosystem disappears forever. His first expedition (and Cape Farewell’s ninth), led him to Svalbard in Norway on a ship named the Noorderlicht, for 22 days. He was exposed to the threatened environment, examined retreating glaciers, and explored scientific research about the region. Research is conducted aboard the ship during each expedition.

In this excerpt from Drake’s poem, he calls on the other artists not to forget what they witnessed in the Arctic:


Farewell 3


Drake also states, “Sailing as close as possible to the vast glaciers that dominate the islands, they saw polar bear tracks on pieces of pack ice the size of trucks. And they tried to understand the effects of climate change on the ecosystem of this most crucial and magnificent part of the world.” His poem portrays the urgency of the “climate challenge.”

Ecotourism at Svalbard in Norway (Source: Woodwalker/Creative Commons).

Two films were also spawned from the Project – “Art From the Arctic” and “Burning Ice.” Both films visually represent some of the Cape Farewell journeys to the High Arctic. “Art From the Arctic” was seen by over 12 million viewers. All the artwork that stems from Cape Farewell expeditions is expected to inspire a public conversation around climate responsibility. Other works generated from Cape Farewell expeditions include exhibitions such as “u-n-f-o-l-d,” an exhibit featuring twenty-five creatives who sailed to the High Arctic, and music festivals such as “SHIFT,” an eight-day music and climate festival held in London’s Southbank Centre.

Svalbard, Longyearbyen Isfjord (Source: Banja&FransMulder/Wikimedia Commons).
Svalbard, Longyearbyen Isfjord (Source: Banja&FransMulder/Creative Commons).

As these voyages occur, the public is kept abreast virtually, through expedition blogs by the artists. The first expedition began with a journey to Svalbard in the High Arctic, chosen as a starting place because of the visible impacts of climate change on the scenery and wildlife, with climate change in the Arctic occurring more rapidly and severely than in other regions of the world.     

Cape Farewell is continuing its mission to engage the public in climate change discussions, with each work created to inspire others to work toward a healthier environment. Current projects include “Space to Breathe,” a response piece to air pollution in urban settings. You can track Cape Farewell’s progress on their website and follow them on twitter @capefarewell.

Listen to Nick recite his poem “The Farewell Glacier” below:

Glaciers Act as Pollutant Transporters in the Arctic

Polar bear and her cubs in Svalbard (source: Alistar Rae/Flickr)
A polar bear and her cubs in Svalbard (Source: Alistar Rae/Creative Commons).

When people think of the Arctic, they often think of polar bears on melting sea ice, not of an area contaminated by pollutants. However, according to an article by Maria Papale et al. in the Marine Pollution Bulletin, findings of polychlorinated biphenyls (PCBs) in the Arctic demonstrate that ice can be a major transporter of pollutants in this remote region. The research team examined the concentration of PCBs in a fjord called Kongfjorden, located in Svalbard in Arctic Norway (79° N, 12° E), in order to understand how the Arctic is affected by pollutants. Given the impact these chemicals can have on human and animal health, the increase in ice melt due to climate change will have serious consequences for the release of these toxins.

Kongsfjorden is located in Svalbard, an archipelago in Arctic Norway (Source: TUBS/Creative Commons).

PCBs are an important type of persistent organic pollutants (POPs); as such, they have a long lifetime in the environment, although they can be broken down by sunlight or some microorganisms. They are compounds once used heavily in the production of refrigerator coolants, electrical insulators and other items from 1929 until the late 1970s, when they were banned in the United States and elsewhere due to health concerns, particularly their carcinogenic effects. The presence of PCBs in Svalbard in the Arctic Basin indicates some form of long-distance transport because the Arctic is thousands of miles from industrial centers where PCBs are produced. Pollutants like PCBs are transported from regions in the northern mid-latitudes into the Arctic by the prevailing winds and ocean currents.

As Papale et al. explain, the PCBs deposited from the atmosphere accumulate on the snow and ice. This deposition has a drastic effect on the region, because PCBs that get trapped in the ice are ultimately released into the environment once the ice melts. For this reason, decades-old PCBs can enter rivers and oceans now, as glaciers melt; they are also emitted when PCB-containing materials wear out through use or when they are burned. In the Arctic, concentrations of PCBs are on average 0.2 ng/m3. Those concentrations have increased since the 1980s, after the banning of PCBs in the United States.

A view of Kongsfjorden (Source: Sphinx/Creative Commons).

Once introduced into the food web, the fate of PCBs depends on which bacteria is present in the environment, since bacteria, such as Actinobacteria and Gammaproteobacteria, possess genetic and biochemical capacities for breaking down PCB pollution. Papale et al. gathered data on the occurrence of cold-adapted, PCB-oxidizing bacteria in seawater and sediment along Kongsfjord, a fjord located on the west coast of Spitsbergen, an island in the Svalbard archipelago. The fjord is fed by two glaciers, Kronebreen and Kongsvegen. The outer fjord is influenced by oceanographic conditions, while the inner fjord is influenced by large tidewater glaciers.

Higher concentrations of PCBs were observed in the water right next to the glacier (due to high flows of sediment and sea currents) or next to the open sea (likely due to water circulation inside the fjord). The higher concentrations of PCBs next to the glacier indicate the influence of glacial meltwater containing PCBs. Once the PCBs arrive in Svalbard Archipelago by long-range transport, they build up in the glaciers on Kongfjorden, sometimes by attaching to fine-grained particles, which are then incorporated into the ice. When the ice melts in the summer, the glacier meltwater containing PCBs flows into the fjord and could also freeze into sea ice in the winter. Sea ice transported from other regions also brings POPs to the region. For example, Arctic Ocean sea ice that forms near Siberia can contain pollutant-laden sediments; it is carried to Svalbard by currents, receiving depositions from the atmosphere as it travels. It can also contain heavy metals like lead, iron and copper, as well as organochlorides like PCBs or DDTs.

A view of one of Kongsfjorden’s glacier (Source: Superchilum/Creative Commons).

Once PCBs enter the waters of Kongsfjorden, they can be absorbed by plankton and other organisms at the bottom of food webs. They become concentrated in the tissues of the invertebrates that eat these organisms. As they pass up the food webs to organisms such as fish, and then to birds and mammals, the concentrations increase, through a process known as bioaccumulation. Recent research has found dangerous levels of these compounds in polar bears, a top predator. As advocacy organizations for these iconic animals have argued, these toxins represent an additional threat to the viability of the species, already challenged by the loss of icebergs and sea ice so critical to their survival. In this way, polar bears can provide testimony to the dangers of chemical pollution, as well as to the dangers of global warming, in the remote high Arctic.

Oxonians Retrace Paths Through Spitsbergen 93 Years Later

The team and their guide on the summit of Poincarétoppen (Source: Liam Garrison/Spitsbergen Retraced
The team and their guide on the summit of Poincarétoppen (Source: Liam Garrison/Spitsbergen Retraced).

During summer, a team of four students from Oxford University, led by undergraduate James Lam, completed a 184-mile expedition across the Ny-Friesland ice cap in Spitsbergen, Norway. Accompanied by a guide, Endre Før Gjermundsen, they skied across the ice cap from July 31 to August 29, retracing the route of a similar expedition conducted by four Oxford University undergraduates in 1923, and collecting scientific data about glaciers along the way.

Spitsbergen is the largest island in the Svalbard archipelago, a territory located within the Arctic circle. Svalbard has more than 2,100 glaciers, constituting 60 percent of its land area, many of which are found on Spitsbergen. The island is also home to many mountains and fjords, giving rise to its name, which means ‘pointed mountains’ in Dutch.

Chydeniusbreen as seen in a photograph taken in 1923 (Source: R. Frazer/The Geographical Journal)
Chydeniusbreen as seen in a photograph taken in 1923 (Source: R. Frazer/The Geographical Journal).

Ny-Friesland in east Spitsbergen has received limited attention from scientists, with little data having been recorded since the 1923 expedition. As such, the team of undergraduates worked with researchers from Oxford University and the University Centre in Svalbard (UNIS) to collect different forms of data on the island’s environment, glaciers and climate.

The expedition was inspired by the discovery of original maps and photos from the 1923 expedition in the archives of the Oxford University Exploration Club. All of the team members, James Lam, Jamie Gardiner, Will Hartz and Liam Garrison, have personal skiing and mountaineering experience spanning three different continents. Nevertheless, they undertook nine months of rigorous training and extensive preparations to ensure the success of both the scientific and physically strenuous aspects of the expedition.

Apart from skiing trips, the training regime included tyre-dragging in Port Meadow, Oxford. (Source: Liam Garrison/Spitsbergen Retraced)
Apart from skiing trips, the training regime included tyre-dragging in Port Meadow, Oxford (Source: Liam Garrison/Spitsbergen Retraced).

During the trip, the students photographed, recorded and collected DNA samples from vascular plants encountered at ten different locations between Duym point in the east and the terminus of Nordernskiold glacier in the west. These samples are currently being analyzed at UNIS and will be added to the Svalbard Flora database. They will provide valuable contributions to understandings of dispersal patterns on glaciers, particularly as there is only one other set of biological data for East Spitsbergen.

The camps of the teams on the 1923 and 2016 expeditions (Sources: R. Frazer/The Geographical Journal and Liam Garrison/Spitsbergen Retraced)
The camps of the teams on the 1923 and 2016 expeditions (Sources: R. Frazer/The Geographical Journal and Liam Garrison/Spitsbergen Retraced).

Using a drone, the students successfully mapped three sections of the Chydeniusbreen glacier. This will be used to create 3D maps of these areas, which will be compared to satellite data and the Norwegian Polar Institute’s models of the glacier to measure glacial change. The team was also able to successfully repeat 25 of the landscape photographs taken on the 1923 expedition. These will be used to practice photogrammetry, the science of measurements done using photographs, to be used in conjunction with the 3-D maps and satellite data to track glacial change in Ny-Friesland.

Two team members ascending the unclimbed west ridge of Newtontoppen (Source: Endre Før Gjermundsen/Spitsbergen Retraced)
Two team members ascending the unclimbed west ridge of Newtontoppen (Source: Endre Før Gjermundsen/Spitsbergen Retraced)

One of the aims of the 1923 expedition was to summit hitherto unclimbed peaks. In the same vein, the 2016 team summitted 8 different peaks, including a number of mountains climbed by the original expedition, such as Poincarétoppen, Mount Chernishev and Mount Irvine. The students also made the first ever ascent of the West Ridge of Newtontoppen, Svalbard’s highest mountain (5,666 ft). These efforts were carried out alongside the scientific aims of the expedition, with the team remaining camped in the base camp of Loven Plateau for a week in order to pursue repeat photography and data collection.

GlacierHub caught up with two of the team members for a short interview about the expedition and what the team intends to do now that they have returned.

GlacierHub: What happens now that the expedition is over?

James Lam, team leader: Now that the expedition is over, I am working to process the data that we collected. I’m collaborating with the Earth Sciences Department in Oxford as well as UNIS and the Norwegian Polar Institute. We hope to be able to publish our findings in due course. We are currently also working with Talesmith (a London-based production company specializing in natural history) to create a film or television series about the expedition.

GH: What was one of the most memorable things about this expedition?

James attempting to recover equipment in a storm (Source: Liam Garrison/Spitsbergen Retraced)
James attempting to recover equipment in a storm (Source: Liam Garrison/Spitsbergen Retraced)

JL: One of the most memorable parts of the expedition was a storm that we were caught in for about three weeks. Despite spending five hours digging into the glacier for shelter and building six foot walls with 100 km/h gusts, it was still too windy to put up the tents, so we were forced to spend the night in a survival shelter. After nine hours huddled together in the shelter, the wind finally died down enough to be able to put up the tents. Luckily, no critical equipment was broken, and we were able to continue after a rest day.

GH: How did it feel embarking on an expedition like this, given the somewhat controversial history of exploration by the British Empire?

A note that the 1923 expedition team left in a thermometer case on the summit of Mt Chernishev (Liam Garrison/Spitsbergen Retraced)
A note that the 1923 expedition team left in a thermometer case on the summit of Mt Chernishev (Liam Garrison/Spitsbergen Retraced).

Jamie Gardiner, team historian: There is quite an anti-intellectual tendency in some quarters to indiscriminately equate the history of exploration with that of imperialism. In 1923, Svalbard was not only terra incognita but terra nulla. Accordingly, it’s rather hard to construct any kind of narrative of exploitation of native peoples. As it happens, in 1925, Britain acted as a signatory of the Svalbard Treaty, which placed Svalbard under Norwegian sovereignty. The treaty expressly forbade militarization and granted unilateral rights to mineral exploitation provided the environmental priorities enshrined were upheld. [The treaty was crafted] without first understanding what it is that is conserved. Therein the mapping of Svalbard had such a key importance.


The team will be releasing a publicly available report about their expedition, along with a documentary to share their journey with a wider audience and compare their polar narrative with that found in excerpts of three diaries from the original expedition. The trailer can be viewed here. Updates about their progress and more spectacular photographs can also be viewed on their Facebook and Twitter pages.


Glaciers Serve as Radioactive Storage, Study Finds

Two cryoconites. Photo courtesy of head researcher Edyta Łokas.
Two cryoconites. Photo courtesy of head researcher Edyta Łokas.

The icy surfaces of glaciers are punctured with cryoconites – small, cylindrical holes filled with meltwater, with thin films of mineral and organic dust, microorganisms, and other particles at the bottom of the hole.

New research conducted by Polish scientists reveals that cryoconites also contain a thin film of extremely radioactive material.

The study confirms previous findings of high levels of radioactivity in the Arctic and warns that as Arctic glaciers rapidly melt, the radioactivity stored in them will be released into downstream water sources and ecosystems.

The study, headed by Edyta Łokas of the Institute of Nuclear Physics at the Polish Academy of Sciences and researchers from three other Polish universities, was published in Science Direct in June.

Sampling during fieldwork. Photo courtesy of Edyta Łokas.

The study examines Hans Glacier in Spitsbergen, the largest and only permanently populated island of the glacier-covered Svalbard archipelago, off the northern Norwegian coast in the Arctic Ocean. While investigating the radionuclide and heavy metal contents of glacial cryoconites, the researchers revealed that the dust retains heavy amounts of airborne radioactive material and heavy metals on glacial surfaces.

This radioactive material comes from both natural and anthropogenic, or human-caused, sources, according to the study. However, the researchers determined through isotope testing that this deposition was mainly linked to human activity.

Head researcher Edyta Lokas says she believes that this radioactive material mainly derives from nuclear weapons usage and testing.

A team researcher in the Hornsund region.
Edyta Lokas in the Hornsund region.

“The radionuclide ratio signatures point to the global fallout [from nuclear weapon testing], as the main source of radioactive contamination on Svalbard. However, some regional contribution, probably from the Soviet tests performed on Novaya Zemlya was also found,” Lokas wrote in an email to GlacierHub.

The Arctic region bears an unfortunate history of radioactive contamination, from an atom bomb going missing at the U.S. base in Thule, Greenland, to radiation from Chernobyl getting picked up by lichens in Scandinavia, making reindeer milk dangerous.

But how does all this radioactive materials end up in the Arctic?

The Arctic, and polar regions in general, often become contaminated through long-range global transport.

In this process, airborne radioactive particles travel through the atmosphere before eventually settling down on a ground surface. While these particles can accumulate in very small, non harmful amounts in soils, vegetation, and animals in all areas of the world, geochemical and atmospheric processes carry the majority of radioactive particles to the Poles.

Once the particles reach the Poles, “sticky” organic substances excreted by microorganisms living in cryoconites attract and accumulate high levels of radioactivity and other toxic metals.

As cryoconites occupy small, but deep holes, on glacier surfaces, they are often left untouched for decades, Edyta explains. Cryoconites also accumulate radioactive substances that are transported with meltwater flowing down the glacier during  summertime.

Hans Glacier in Spitsbergen, the largest and only permanently populated island of the Svalbard archipelago in Norway. Photo courtesy of Edtya Lokas.
Hans Glacier in Spitsbergen, the largest and only permanently populated island of the Svalbard archipelago in Norway. Photo courtesy of Edtya Lokas.

Climate change lends extra meaning to the study, as the researchers note that, “the number of additional contamination sources may rise in future due to global climate changes.”

They expect that both air temperature increases and changes to atmospheric circulation patterns and precipitation intensity will all quicken the pace of contamination transport and extraction from the atmosphere.

Edtya explained that as Arctic glaciers retreat, “The radioactivity contained in the cryoconites is released from shrinking glaciers and incorporated into the Arctic ecosystem.” She said she hopes that future climate change vulnerability assessments of the Arctic to pollution consider cryoconite radioactivity.

Ice loss surpasses poaching as largest threat to Barents Sea polar bear

Prior to the 1970s, hunting decimated polar bear populations across the Arctic. The international community has made strides in protecting the iconic species from over-harvesting through conservation agreements, which have helped the species start to recover. However, a review paper published in Polar Research in July suggests that the road to recovery is far from over, as ice loss now replaces poaching as the most pressing threat to polar bear survival in the Barents Sea area, north of Norway and Russia.

Polar bear in Svalbard, Norway (Source: Arturo de Frias Marques)
Polar bear in Svalbard, Norway (Source: Arturo de Frias Marques)

The paper, written by Magnus Anderson and Jon Aars, of the Norwegian Polar Institute, comprehensively covers the history of polar bear population changes over the course of 100 years. By examining historical documents and current scientific studies, the authors find that ice loss, in conjunction with human encroachment on habitat and pollution, have replaced hunting as the largest threat to polar bear populations in the Barents Sea area.

Somewhere between 100 and 900 polar bears were poached each year between 1870 to 1970 in Greenland and the Barents Sea region. Arctic countries then came together to protect the species as the bears were pushed toward the brink of extinction. In 1973, the Agreement on the Conservation of Polar Bears was facilitated by the International Union for Conservation of Nature and signed by five countries, marking an important step in the conservation of the polar bear and Arctic ecosystem. With the additional support of Russia’s and Norway’s polar bear hunting bans, enacted in 1956 and 1973, respectively, the Barents Sea polar bear’s outlook became more promising.

In Svalbard, a glacier-rich archipelago north of the Norwegian mainland, polar bear populations doubled in the decade following the conservation agreement. There were approximately 2,000 bears in the region as of 1980. While population recovery occurred, it happened slower than anticipated by the scientific community.

The Barents Sea and surrounding land areas (Source: Polar Research)
The Barents Sea and surrounding land areas (Source: Polar Research)

The Intergovernmental Panel on Climate Change mentioned the impacts of climate change on sea-ice cover for the first time in its third assessment in 2001. The inclusion of ice loss in the report shed light on a potential new threat to polar bear populations, which depend on the Arctic ice for their way of life. It also offered an explanation for the slow recovery of the species following the Russian and Norwegian poaching bans.

According to current assessments, the polar bear habitat in the Barents Sea will substantially decrease over the next few decades due to ice loss and glacier retreat, as a consequence of anthropogenic climate change. Polar bear populations are expected to decline accordingly.

The Polar Research study states that the main reason for the loss of polar bear populations will be the loss of an ice “platform” needed to hunt for prey — ringed, bearded, and harp seals. As the ice melts, polar bears lose their hunting grounds and must travel greater distances under more treacherous conditions in order to find food. Anderson and Aars cite prior studies conducted by Carla Freitas, Ian Stirling, and others which have tracked trends in polar bear movement with GPS collars and have found that the thickness and persistence of ice significantly affects the location of polar bears and their hunting grounds.

Ringed seal, polar bears' main prey (Source: NOAA)
Ringed seal, polar bears’ main prey (Source: NOAA)

In addition to impacting the species’ hunting ability, ice is critical for breeding, traveling, and denning. A loss of  habitat means fewer travel routes for males to find females during the breeding season and a drop in breeding rates across the Arctic. According to the authors’ research, when females have to give birth and raise their cubs, they are hard-pressed to find suitable denning and birthing areas. In the fall, the ice and snow begins to accumulate progressively later in the year due to higher temperatures, making it difficult for females to find the solid ice on which they prefer to give birth. In the spring, the sea ice, which creates a safe den for polar bear cubs, retreats earlier in the season and faster, putting the babies and their mothers at risk.

Mother with her cub (Source: Scott Schliebe, US Fish and Wildlife Service)
Mother with her cub (Source: Scott Schliebe, US Fish and Wildlife Service)

The report cites research showing the late arrival and early retreat of ice has impacted both mother and cub body size, health, and survival rates.

Pollution and human disturbance are two other stressors negatively impacting polar bear populations. When these threats are combined with ice loss, the cumulative impact can be deadly. For example, human presence in polar bear habitat, combined with diminished ice, can lead to less effective hunting, malnutrition, and higher mortality rates. And when endocrine-disrupting pollutants are combined with the impacts of climate change, it causes the “worst case combination for arctic marine mammals and birds,” according to the study.
While the threat of poaching has diminished substantially following international agreements and conservation efforts, polar bears continue to face equally serious, but different risks. The report concludes that in order to protect the polar bear, an iconic species that contributes to overall Arctic health, there is a need for new agreements comprehensive management strategies to address the impacts of ice loss, pollution, and human disturbance in the Arctic.

Polar Ecology in Flux Due to Climate Change

Glacial melting and rising ocean temperatures are affecting the feeding, breeding and dispersion patterns of species, such as krill, cod, seals and  polar bears, in the polar regions, according to two recently published research articles. This climatic shift could create an imbalance in the regional ecology and negatively impact numerous species as the effects of climate change worsen.

The first article reflects on how a threat to a key species in Antarctica may shake up the food chain, while the other considers how a changing habitat in the Arctic could skew the population trends of several interconnected species and create a systemic imbalance in the ecosystem.

Glacier-originated melt-water creek carrying large amounts of particles. (Source: V. Fuentes/Nature)

After a nine-year study of krill in Potters Cove, a small section of King George Island off the coast of Antarctica, a team of South American and European marine biologists published their research this past June in the scientific journal Nature.

Krill are shrimp-like sea creatures that feed mostly on plankton.  Since they extract their food from the water by filtering it through fine combs, they are known as filter feeders.  Krill are found in all oceans and are an abundant food source for many marine organisms.  In the polar regions, predators such as whales often rely on krill as their only consistent food source.

The authors of this first piece found that a destruction of the krill population could extend undermine the Antarctic food web that relies on the presence of the small creatures.

 The study launched after stacks of dead krill washed ashore at Potters Cove in 2002, lining the coast. The article’s nine authors, Verónica Fuentes, Gastón Alurralde, Bettina Meyer, Gastón E. Aguirre, Antonio Canepa, Anne-Cathrin Wölfl, H. Christian Hass, Gabriela N. Williams and Irene R. Schloss, suggest the first observed  and subsequent stranding incidents are connected to large volumes of particulate matter dumped into the ocean by melting glaciers. The high level of tiny rock particles carried by the glacial melt water may have clogged the digestive system of filter feeders like krill.

The researchers conducted a series of experiments in which they exposed captive krill to water with varying amounts of particulates. The krill’s feeding, nutrient absorption and general performance were all significantly inhibited after 24 hours of exposure to concentrations of particles similar to those found in the plums of glacial runoff.

Stranded krill along the southern shore of Potters Cove, King George Island (Source: V. Fuentes/Nature).

Although krill are mobile creatures and can usually avoid harmful environments, exposure to the highly concentrated particles interfered with their ability to absorb nutrients from their food.  The krill became weak, which resulted in their inability to fight local ocean currents and their subsequent demise.

About 90 percent of King George Island is covered in glaciers that are melting and discharging particles into the surrounding marine ecosystem, according to the article.  Similarly, an overwhelming majority of the 244 glacier fronts, a location where a glacier meets the sea, studied on the West Antarctic Peninsula have retreated over the last several decades, which suggests that high particulate count from glacial meltwater may be occurring in other parts of Antarctica.

Since much of the Antarctic coast is not monitored and most dead krill sink to the bottom of the ocean, the authors caution that these stranding events likely represent a small fraction of the episodes.  

In another recent study on climate change’s impacts on wildlife, scientific researchers with the Norwegian Polar Institute focus their attention on the high Arctic archipelago of Svalbard, Norway.  They found that glacial melting and changes in sea ice have impacted numerous land and sea animals in the Arctic. These shifts have the potential to influence more creatures. The study, by Sebastien Descamps and his coauthors, was published this May in the scientific journal Global Change Biology.

Tidewater glacier in Greenland, taken from helicopter (Source: Brocken Inaglory/CC)

Some species, such as the pink-footed goose, are benefiting from the warming Arctic climate, however. Lower levels of spring snow cover and earlier melting has expanded the time for its breeding and the area of available breeding grounds, which will likely lead to an increase in the geese population.  

However, the success or the overpopulation of one species can cause an imbalance in the ecosystem and negatively affect numerous other organisms.  As the authors explain, “An extreme increase in a herbivore population [like the geese] has the potential to affect the state of Svalbard’s vegetation substantially, with possible cascading consequences for other herbivorous species and their associated predators.”

The authors conclude, “even though a few species are benefiting from a warming climate, most Arctic endemic species in Svalbard are experiencing negative consequences induced by the warming environment.”

Polar bears and the Arctic ringed seal are among the species which are suffering the impacts of a warming Arctic.  Seals breed on sea ice and depend on snow accumulation on the ice in order to form lairs for their pups.  The snow lairs provide protection from the harsh winter and predators.  As ocean temperature warms and the season of sea ice formation shortens, there is less time for accumulation of snow.  Thus, many seals are giving birth on bare ice, which leads to a much higher pup mortality rate.

Weddell seals (Source: changehali/CC).

This  article also points out that tidewater glaciers have become increasingly important foraging areas for several species, including seals, seabirds and whales.  Additionally, these creatures’ presence makes the glacier fronts fruitful hunting grounds for polar bears. Icebergs drifting near the glacier fronts create valuable resting areas in the hunting grounds for many of these animals.

The authors hypothesize that the increase in icebergs calved from the glacier fronts could counterbalance the ecological loss resulting from the disappearance of sea ice. Yet this may only offer a brief reprieve for the Arctic species that depend on the ice.  

“Continued warming is expected to reduce the number of tidewater glaciers and also the overall length of calving fronts around the Svalbard Archipelago.  Thus, these important foraging hotspots for Svalbard’s marine mammals and seabirds will gradually become fewer and will likely eventually disappear,” wrote the authors.

Taken together, these two recent articles show that glacier retreat, as well as other forms of loss of ice, have negative impacts on high-latitude ecosystems, both in the Arctic or in Antarctica. There are strong similarities between these two cases, distant from each other in spatial terms but close to each other in their shared vulnerabilities.

Photo Friday: Kronebreen Glacier in Svalbard

This week’s Photo Friday features images from a research project in Svalbard. GlacierHub has interviewed two members of the research team.

Nick Hulton, a team member, explained:

Kronebreen is one of the fastest flowing glaciers in Svalbard, which is an Arctic archipelago situated north of mainland Norway. The glacier drains a large ice cap, transferring ice down a narrow valley that terminates within a fjord, producing a dramatic 3 km-wide ice cliff. The CRIOS (Calving Rates and Impact on Sea Level) research group, headed by Prof. Doug Benn, has been working there for a number of years to better understand how and when ice will be transferred to the oceans, and how this will affect future global sea levels.

Two CRIOS members, Penny How and Nick Hulton from the University of Edinburgh and the University Centre in Svalbard (UNIS), are using time-lapse cameras to understand how this glacier is changing and the processes that cause icebergs to break off into the ocean. The cameras take high-resolution pictures every thirty minutes, and by tracking individual features form image to image, can be used to measure how fast the glacier is flowing.

Penny How, a research student in the team, added “We are currently putting 11 time-lapse cameras at Kronebreen, in an attempt to generate sequential digital elevation models using Structure from Motion (i.e. three-dimensional time-lapse).”

Videos produced from these images give a good impression of how the glacier moves and can be seen here:

This one gives a taste of the fieldwork involved to install these time-lapse cameras:

Images from Penny How and Nick Hulton

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On Glaciers, Moss Become Asexual

A recent study from the journal Czech Polar Reports presents interesting findings about a rarity on glaciers: moss.

Glacier Mosses(Credit: Flickr)
Glacier Mosses(Credit: Flickr)

When glaciers have a certain amount of moisture and cryoconite—a base layer that consists of small rock particles, soot, and microbes that have accumulated on glaciers— sometimes mosses can grow on them. While it is not common to see moss on glaciers, according to a paper by Olga Belkina, a researcher at the Institute of the Kola Science Centre of the Russian Academy of Sciences, they have been found on a few glaciers in Alaska, Iceland, and Svalbard, Norway.

There are some moss attributes that contribute to the mosses’ tolerance of the brutal living conditions found on glaciers. First, moss do not absorb nutrients from the substrate, the layer to which they are attached, since mosses do not have roots. They absorb water and nutrients directly through their leaves. Mosses only have rhizoids–threadlike tissues which look like roots, but function only to attach to the surface they grow on and can’t absorb water or nutrients from soil or any other substrate.

Second, mosses have have the ability to adapt to a wide range of light levels, which means some types of mosses can survive under massive exposure to sunlight. Some mosses are found in the desert, and some can survive with the low intensity of sunlight found in polar areas.

Glacier Mosses(Credit: Flickr)
Glacier Mosses(Credit: Flickr)

Although glacial areas aren’t the ideal living conditions for mosses, there are still the minimum living requirements for them to grow. There is enough moisture and little competition from other plants, allowing them to survive.

One mystery of the development of mosses found on ice is that how they reproduce in such cold areas. “Failure of sex reproduction of many mosses is widespread in the high polar regions,” the study reports.

The alternative is asexual reproduction. Reproduction strategies for most species fall into two categories, sexual reproduction and asexual reproduction. The offspring of the asexual reproduction process are identical to a single parent, while the offspring from sexual reproduction received genetic information from both parents.

An interesting finding, according to Belkina’s study, is that Schistidium abrupticostatum, a type of moss found on the ice of Bertilbreen, Svalbard, produces gametangia–an organ which produces gametes that can fuse with another cell during fertilization to sexually reproduce. However, the mosses do not evolve into sporophytes, or the non-sexual phase of a plant.


Glacier mice(Credit: Wikimedia)
Glacier mice(Credit: Mental_Floss)

Normally plants would alternate between a sexual phase (gametangia) and a non-sexual phase (sporophyte). During the non-sexual phase, plants grow larger and taller to produce spores through meiosis. Then the spores divide into gametes, or sex cells. A gamete from one plant can merge with another gamete, completing a set of chromosomes to start the next round of reproduction.

Generally, mosses do not develop into gametophytes in harsh conditions like glaciers, even though they do in areas that are near the glaciers. Many mosses can be brought to the glaciers by wind and then settle on surface and substratum, yet only a few have the chance to create long-lived populations in such cold conditions.
Each clump of moss on glaciers consists of genetically identical individuals, and the populations grow by the asexual method, which means new mosses can regenerate from a small section of existing moss plants.

Roundup: Kelp, Firn, and Plankton Studied in Svalbard

Each week, we highlight three stories from the forefront of glacier news.

Warming of Artic  Changes Kelp Forests’ Density and Depth

From Polar Biology:

Kelp Seaweed. Courtesy of Flickr User snickclunk.
Kelp Seaweed. Courtesy of Flickr User snickclunk.

“Arctic West Spitsbergen in Svalbard is currently experiencing gradual warming due to climate change showing decreased landfast sea-ice and increased sedimentation. In order to document possible changes in 2012–2014, we partially repeated a quantitative diving study from 1996 to 1998 in the kelp forest at Hansneset, Kongsfjorden, along a depth gradient between 0 and 15 m. The seaweed biomass increased between 1996/1998 and 2012/2013 with peak in kelp biomass shifted to shallower depth, from 5 to 2.5 m.”

Read more about this study here.


Firn, Newly-Settled Snow on Glaciers, Stores Water

Firn, courtesy of Flickr User Alpen Picasso.
Firn, courtesy of Flickr User Alpen Picasso.

From  Geophysical Research Letters:

“Ice-penetrating radar and GPS observations reveal a perennial firn aquifer (PFA) on a Svalbard ice field, similar to those recently discovered in southeastern Greenland. A bright, widespread radar reflector separates relatively dry and water-saturated firn…Our observations indicate that PFAs respond rapidly (subannually) to surface forcing, and are capable of providing significant input to the englacial hydrology system.”

Read more about this study on firn hydrology here.


Krill and Crustaceans Play Bigger Role in Warming Ecosystem

From Polar Biology:

Polar Cod, which relies on plankton, being dried in Norway. Courtesy of Flickr User Victor Velez.
Polar Cod, which relies on plankton, being dried in Norway. Courtesy of Flickr User Victor Velez.

“Euphausiid (krill) and amphipod dynamics were studied during 2006–2011 by use of plankton nets in Kongsfjorden (79°N) and adjacent waters, also including limited sampling in Isfjorden (78°N) and Rijpfjorden (80°N). The objectives of the study were to assess how variations in physical characteristics across fjord systems affect the distribution and abundance of euphausiids and amphipods and the potential for these macrozooplankton species to reproduce in these waters…Euphausiids and amphipods are major food of capelin (Mallotus villosus) and polar cod (Boreogadus saida), respectively, in this region, and changes in prey abundance will likely have an impact on the feeding dynamics of these important fish species”

Learn more about these ecosystems here.

Roundup: Icebergs, Mobile Toxins, Festive Algae

Iceberg Ahead! A New Study Finds Way to Avert Disaster

“When performing offshore operations in the Arctic, there are several challenges. One of those challenges is the threat of icebergs on offshore structures and vessels. Icebergs can exert extremely high loads on vessels, offshore platforms, and seabed installations.”

Arctic iceberg photographed aboard the NOAA Ship Fairweather. (Courtesy of :NOAA's National Ocean Service /Flikr)
Arctic iceberg photographed aboard the NOAA Ship Fairweather (Courtesy of :NOAA’s National Ocean Service

Find out how the team is proposing safer Arctic travels.


 Glaciers Retreat Toxic Metals Are on the Move in Tibet

“In mountain ecosystems, the most important natural source of trace metals is from the weathering of parent materials. However, in recent decades, the metals in mountain regions are mainly from anthropogenic sources including mining, refinement, and fuel combustion. Considering the toxicity of trace metals, it is necessary to investigate and evaluate their mobility and eco-risk in mountain ecosystems.”

Cadmium, one of the elements of concern found in Tibetan soil. (Courtesy of :Images of Chemical Elements/Wikimedia))
Cadmium, one of the elements of concern found in Tibetan soil. (Courtesy of :Images of Chemical Elements/Wikimedia))

Learn more about the possibly toxic soil exposed as glaciers retreat.


With Red and Green Snow, Algae Just Misses Christmas Season

“We demonstrate that green and red snow clearly vary in their physico-chemical environment, their microbial community composition and their metabolic profiles. For the algae this likely reflects both different stages of their life cycles and their adaptation strategies. ”

Red and green algae plumes atop Californian water fields. (Courtesy of :Caribb /Flikr)
Red and green algae plumes atop Californian water fields. (Courtesy of:aribb

Read more about the colorful algae and what it means for soil quality.


Roundup: Gloomy Glaciologist, Icy Blasts, and New Models

Glaciologist Causes Chills with Not So Icy Predictions

“How does being the one to look at the grim facts of climate change most intimately, day in and day out, affect a person? Is Box representative of all of the scientists most directly involved in this defining issue of the new century? How are they being affected by the burden of their chosen work in the face of changes to the earth that could render it a different planet?”

(Photo:NASA's Goddard Space Flight Center/Jefferson Beck, please contact the photographer before using)
A man collects meltwater temperatures in Greenland, where Box does most of his research. (Photo:NASA’s Goddard Space Flight Center/Jefferson Beck, please contact the photographer before using)

Read more about the man who, for better or for worse, set off climate alarm bells.


Could Climate Change Cause More Icy Blasts?

“The degree of activity of the volcano provides a semiquantitative indication concerning the probability of future eruptive activity, but changes in snow and ice as induced by climate change and/or volcanic activity can superimpose fast or slow trends with respect to hazards and risks related to volcanoe-ice interactions…”


The paper speaks of the particular risks the eruption of Mt. St Helens caused. (Photo: Eric Prado/Flikr, please contact the photographer before using)

Read more about the risks of volcano-ice interactions and how those risks might effect society.

High Resolution Model Accurately Recreates Glacier Variability

“Altogether, the model compares well with observations and offers possibilities for studying glacier climatic mass balance on Svalbard both historically as well as based on climate projections.”

Glaicer calving in Svalbard. (Photo:Gary Bembridge/Flikr, please contact the photographer before using)
Glaicer calving in Svalbard. (Photo:Gary Bembridge/Flikr, please contact the photographer before using)

Read more about how the researchers were able to get their models so accurate.