Burning Questions

Scientists Seek Information from the Anaktuvuk River Fire

By Emily Stone

Journalists visited the site of the Anaktuvuk River Fire last summer. The charred tussocks were still visible beneath the blooming cottongrass. Photo: Lisa Jarvis

Gaius Shaver has been traveling to Toolik Field Station for 34 summers to study how tundra ecosystems react to small environmental changes. One of his experiments involves building greenhouses over 8-by-16 foot plots of land to gauge how plants react to warmer soil.

His research has yielded interesting results over the years, but there’s always been a question of how well that data would translate over large tracks of land.

Suddenly, Mother Nature gave Shaver and many other Toolik scientists a way to find out.

A massive fire burned about 400 square miles of tundra along the Anaktuvuk River from July to October 2007. It was the largest tundra fire ever recorded on Alaska’s North Slope. Now the scientists are studying how the area, which is roughly the size of Cape Cod, responds. In addition to examining the warming soil and plant changes, the group is looking at how much carbon was lost in the fire, the ongoing exchange of carbon between the land and air, and how melting permafrost is affecting rivers and streams. They’re finding that the fire has had a significant impact in all these areas. And given that continued warming in the Arctic will likely lead to more lightning which will lead to more fires, these are important questions to answer.

The 2007 Anaktuvuk River Fire burned a Cape Cod-sized section of the North Slope. Scientists are interested in how long it will take the area's plants and soil to recover. Photo: Adrian Rocha

“There’s a lot going on,” said Shaver, a senior scientist at the Marine Biological Laboratory who is leading the National Science Foundation-funded, three-year study that includes nine senior collaborators and a couple dozen other researchers. “It’s very exciting.”

The group calculated that the fire burned more than two million tons of carbon that had been stored in the soil, or roughly 25 years worth. This equals about 10 percent of the annual carbon emissions for the city of Boston. The fire also burned between 300 and 1,000 years worth of nitrogen.

The group is also interested in the continued changes in carbon exchange between the soil and atmosphere. Using instruments set up on three towers in the burn site, they’re measuring the exchange of carbon during the summers. If plants photosynthesize more than they and the soils in which they grow respire, then the net result is carbon being removed from the atmosphere. If there’s more respiration than photosynthesis, then the opposite is true.

Overall, the burned areas have a net carbon loss from the soil, meaning more carbon is being released into the atmosphere than at unburned spots. The researchers calculated that in 2008, the fire accounted for a minimum 2.8 percent reduction in the amount of carbon being taken out of the atmosphere across the North Slope even though the Anaktuvuk River Burn accounts for only 0.55 percent of the North Slope’s area.

The researchers know from older fires and erosion scars that shrubs tend to dominate the landscape after a disturbance at the expense of mounds of tussock grasses, which cover much of the North Slope. This seems to be playing out at the Anaktuvuk River Burn. Although shrubs were knocked back dramatically by the fire — even more than the tussocks — they are recovering rapidly even in severely burned areas and may soon exceed the grasses in the amount of ground they cover. 

Undisturbed tundra tends to keep its plants in pretty consistent ratios as they compete for limited resources in the soil. “A disturbance shakes up those relationships among species,” Shaver said. This is important because shrubs tend to insulate the soil in the winter, keeping it warmer, and also hold less carbon below ground than tussocks do, both of which can further change the landscape.

Another striking discovery is the change in albedo, meaning the percent of the sun’s radiation that is reflected away from the ground. In the first summer after the fire unburned portions of the burn site had a 17 percent albedo while severely burned sections had a 3.5 to 4 percent albedo. That means an additional 13 percent of the sun’s radiation was being absorbed in those areas. And that heat has to go somewhere, often warming the soil to higher temperatures and permeating deeper than normal. This difference was less in 2009 than in 2008, and Shaver said it will eventually return to the level of unburned tundra. 

Data show that burn scars absorb more of the sun's radiation than unburned tundra, increasing soil temperatures. Photo: Adrian Rocha

In the meantime, increased heat flux into the ground can cause thermokarst failures, which occur when the ice that’s normally frozen solid in permafrost melts and the land above it collapses like a soufflé. Last summer the group noticed more and more of these depressions as the season continued. When thermokarst erosion happens near streams and lakes, it dumps extra nutrients into the water, giving microbes, plants and fish access to more food and thus changing the aquatic ecosystems. 

“We can’t make a treaty to stop thermokarst and fires,” said Syndonia Bret-Harte, an associate professor at the University of Alaska Fairbanks, who is heading up the plant studies at the burn.

Bret-Harte, who is also Toolik’s associate science director, was at the station in 2007 while the fire was burning about 25 miles away and at times could see a wall of smoke in the distance.

“It was awesome and beautiful, but disturbing at the same time,” she said.

Once the scientists realized how big the fire was, Shaver applied for an NSF grant for the following summer, knowing how valuable the natural experiment would be for the scientists at Toolik, many of whom are part of an ongoing Long Term Ecological Research Project, one of 26 in the U.S. LTER network.

The group is adding a component to this summer’s research by visiting the sites of two large fires from 1993 to see how they’re recovering in hopes of predicting how the Anaktuvuk River Burn will fare in the coming years. They’ll take measurements to see, for example, how much soil has accumulated above the char level and what the diversity of plant species is like.

All of this is crucial information to have as more and more disturbances like lightning-driven fires and thermokarst occur across the Arctic.

“Overall climate change is gradual and the overall response to this change is gradual,” Shaver said. “But then we have these patches of intense change and the patches may be changing so intensely that from the perspective of the whole North Slope, they actually dominate the overall changes.”

Delivering Boardwalk

PFSers Larry Gullingsrud and Annelisa Neely deliver boardwalk to Mike Weintraub's tundra plots at Imnavait Creek. Researchers will use the dark material in the background to artificially warm some of the tundra plots. Photo: Jason Neely

University of Toledo’s Mike Weintraub returned to Imnavait Creek near Toolik Field Station last week for the first full season of tundra plot studies supported by his recent NSF grant.  The project is one of a group of new research to be fielded at/near Toolik this year to study changing seasonality in the Arctic (CSAS).  Specifically, Weintraub’s team is looking at how altered timing of seasonal events—earlier spring thaw and later fall freeze, for example—may affect nitrogen cycling in the soil, and how that in turn impacts tundra plant and microbe growth.

Polar Field Services staff returned to Toolik in late April for spring science support and station facilities projects. Among the larger science efforts, Jason Neely’s team placed about 3000 linear feet of boardwalk out on Imnavait Creek tundra manipulation plots for Weintraub’s CSAS soil nutrient experiment.   The boardwalk protects the fragile, slow-growing tundra from the many footsteps of researchers visiting the plots to collect plants, data and/or to manipulate the conditions.  The Weintraub team will continue working on the CSAS project for the length of the summer season at Toolik Field Station, departing in late August.

Weintraub heads an interdisciplinary collaboration composed of four other PIs:  Paddy Sullivan (U Alaska), Josh Schimel (U California), Edward Rastetter (Marine Biological Laboratory), and Heidi Steltzer (Colorado State U).

Researchers will manipulate the timing of seasonally driven processes in tussock tundra ecosystems by advancing the timing of snowmelt with radiation-absorbing fabric placed over the snowpack in the late spring and by using open-top warming chambers in concert with advanced snowmelt. They will follow how seasonally driven plant and soil dynamics are affected by changes in the timing of snowmelt and warming.

Being COY

Polar bear cubs captured, inspected, and released by Hank Harlow's research team. Photo: John Whiteman

The Bears of Summer is back–that’s John Whiteman’s contribution to a collection of polar research dispatches called Ice Stories maintained by the San Francisco Exploratorium. Whiteman, a PhD student in the University of Wyoming’s Program in Ecology, has returned to Kaktovik on Alaska’s north coast for early spring fieldwork.  He’s part of Hank Harlow’s polar bear physiology study, an NSF-funded research project that aims to understand to what extent warmer summer temps–and attendant changes in sea-ice coverage–may impact polar bears who use the ice as a hunting platform. The Harlow team has been capturing, examining, tagging and releasing bears early and late in the growing season since 2008 to find out if they are successfully feeding during the summer, and if not, how they may be using their own body’s resources (mainly fat) for sustenance.

In his latest post, Whiteman writes about examining a gigantic male, the largest bear he’s ever handled. He also comments on the number of COYs he’s seeing–“COYs” being cubs born around January. The above three are taking a snooze on their bear mama while waiting for  a short-lasting dose of anesthesia to wear off.

So far, the team has had some success in recapturing bears tagged last year and in capturing new ones as well; this is particularly good news given that last fall’s capture and study period was hampered by poor ice conditions that prevented the researchers from safely reaching the bears.

Paddy’s Put-in

Smoke curls from the wood stove at Paddy Sullivan's camp site. Photo: Christie Haupert

Christie Haupert helped Paddy Sullivan (University of Alaska) put in to his remote research site in Alaska’s Noatak National Preserve earlier this week. They flew in to Kotzebue and rode snowmachines on flagged paths to the Agashoshak River, from there traveling up river on the Aggie’s frozen surface until they reached Paddy’s site. Christie sent a note describing her adventures.

Kotz was great. As we landed at this small community frozen into a tiny spit of land surrounded by sea ice, a snowmachine whizzed by a dog-sled team. I wondered, are they both off to get groceries, or maybe just to stretch their legs a bit? Welcome to the bush – I couldn’t help but smile.

Kotzebue. Photo courtesy http://www.chukchi.alaska.edu

Our hosts were Lars and Meghan Nedwick, an amazingly super cool couple with a 4-year-old, Otto, and a 2-year-old, Arnie. Talk about HIGH ENERGY – whew, I was exhausted just hanging out in the kitchen. Give me 100 miles of skiing any day instead of trying to keep two young boys entertained when it’s -20 F and blowing outside. The Nedwicks put us up in their house.  A warm, freshly baked spaghetti pie was waiting for us when we arrived, filled with fresh musk-ox meat from the neighbor. Paddy slept on the floor, I on the pull-out couch.  

We snowmachined two rigs out to the site on the Agashoshak on Tuesday. There was just one mile of visibility when we left, but thanks to a well-wanded “road” system we didn’t lose our way. The Brooks Range, like much of the interior and northern Alaska, has suffered a very low snow year. There was not enough snow on the ground to travel across tundra so we stuck to just the river systems. This meant fun on ice. Paddy’s machine did some nice twirls along glare ice a few times.  A bit more cautious, I managed not to spin doughnuts.

Our home was a cozy 8’x8’ Arctic Oven, equipped with portable woodstove and all. Once we learned how to manage the stove and not smoke ourselves out of the tent each time we put on a log, it made for fairly comfortable accommodations – certainly the warmest winter accommodations I have stayed in away from line power. The mountaineer in me had a hard time truly relaxing, it felt almost too plush. It was weird not to travel via human power, not to carry everything on my back and mostly it was weird to have a heated tent to sit in at night.

The next day, clear and sunny, was spent working on weather stations, including one that had been ravaged by a bear earlier in the fall, and digging snow “pits.” With a snow pack not much deeper than 40 cm, we didn’t really have to dig. Paddy is partly interested in how trees respond to different stressors – snowmelt, drought, etc. The snow pits help to characterize the snow conditions and to estimate the initial pulse of water the trees will receive at spring break-up. Paddy even commented that he hopes this year proves to be another drought, as it always results in interesting data.

After a fitful night’s sleep resulting from -20 F temps and a popped luxury camp thermarest (always bring back up sleeping pad when winter camping), we arose to yet again brilliant sunshine, hopeful for an eventful day. We shuttled a few deep-cycle batteries to the new sites Paddy will outfit with weather stations this spring. The rest of the day was spent trying to get one of the two snowmachines started. Despite having it hooked up to a generator for more than six hours, it wouldn’t start. At 6:00p.m., we decided to abandon it and ride back together on the other snowmachine.  My hope for an eventful day wasn’t quite what I imagined, sitting in a pristine area in the western Arctic listening to the drone of a small generator and trying to get a snowmachine started.

The snowmachine pulls a sledge full of science gear and camping supplies. Photo: Christie Haupert

The three-plus hour ride was tolerable, as it gave me a chance to just take in the scenery and not concentrate on the driving. My mind was mostly lost in thought about what we could have done to have avoided stranding a snowmachine.  It turned out there was water in the gas tank; even the rescuers had to tow it back to Kotzebue and warm it up in a garage before it would start. Thankfully for my ego, it wasn’t user error.

Friday was going to be my walk-about day, getting to know Kotz. Instead Lars Nedwick, who happens to fly for Bering Air, offered me the co-pilot seat on a trip to three nearby villages:  Ambler, Kobuk, Shungnak.

I couldn’t turn down that opportunity. We loaded up the Caravan with 1500 pounds of soda pop (not kidding) and five passengers. We stopped in Ambler to drop off some mail, then in Kobuk we dropped off most of the passengers. Shungnak was the recipient of the soda.

We also had a State Trooper fly with us because in Shungnak there was a “perp” waiting in handcuffs to be escorted back to Kotz for an arraignment hearing. It was a real snapshot of village life.

Crammed into five days I had at least five new experiences and learned a lot while I was out there. The folks that live in bush Alaska are really of a different breed. Good stuff.

The Arctic Food Chain: Mercury and Polar Bears

A recent study found that polar bears predating 1950 that ate a phytoplankton-based diet have higher concentrations of mercury in their systems than bears that eat diets based from the ice algae food web. Photo: Jerzy Strzelecki

The looming threat of melting sea ice has raised awareness about climate change’s impact on polar bears, an endangered species. Also relevant—and less studied—is how changes to the earth—and melting sea ice—could affect the species’ diet. 

Which may be why a recent study in the December issue of the journal Polar Research that establishes two different primary food webs for polar bears and documents surprisingly higher mercury levels in bears that eat from one specific web garnered interest from both the scientific community and science journalists. 

Mercury concentrations can be poisonous to humans and other members of the food chain; currently scientists do not know what levels of mercury are dangerous to polar bears. 

(Note: mercury is not a greenhouse gas, nor is it associated directly with global warming. However, high concentrations of mercury in polar bears is significant to scientists for complex reasons outlined below.) 

Diet Details 

 The study confirmed that polar bears got their food from two primary food webs: 

• Phytoplankton-based, which begins with single-celled plants inhabiting the top layer of the ocean 

• Ice algae-based, which begins with microscopic plants living within and below the sea ice 

The research went further, analyzing mercury concentrations in the bears’ fur. 

They found that polar bears chowing down on the phytoplankton-based food chain, which originates in the open ocean in the absence of sea ice, had greater concentrations of mercury in their bodies than bears whose diet traced back to the ice algae. 

Dr. Joel Blum, principal investigator, collects snow samples to test for mercury concentrations near Barrow, AK. Photo: Joel Blum

Mercury Investigations 

One of the study’s authors, Joel Blum, the John D MacArthur Professor of Geological Sciences, and Professor of Ecology at the University of Michigan, said the findings are significant as scientists strive to learn more about mercury, an inorganic element whose presence in the atmosphere has tripled since the industrial revolution. 

“Very little is known about how mercury moves around the globe,” said Blum. “But we know humans have increased the amount of mercury in the environment.” 

Mercury can stay in the atmosphere for up to a year and travel to far reaches of the globe, and scientists have documented a considerable amount of mercury deposited in the Arctic. Studying the bears provides important background data on earlier mercury levels, Blum said. 

Factory emissions are a major source of mercury pollution. Photo: courtesy Air Resources Laboratory, NOAA

Museum Bears 

Blum and his colleagues analyzed mercury concentrations in polar bears that predated 1950, before the major influx of mercury from coal-burning power plants and other industrial activities that send mercury into the atmosphere. 

Specifically, they analyzed the late-19th- and early-20th-century polar bear hair for the chemical signatures of nitrogen isotopes, carbon isotopes, and mercury concentrations, looking back in time to a period before man-caused mercury emissions escalated. 

“We know that due to human inputs mercury distribution in the Arctic is currently heterogeneous (multi-faceted and complex), so we decided to take a step back and understand the fundamental processes, pre-1950,” said Blum. 

Phytoplankton Diets = High Mercury Concentrations 

 The discovery that bears that eat on the phytoplankton food chain have significantly higher mercury concentrations suggests that as sea ice melts and bears eat more phytoplankton-based diets, their mercury concentrations could increase, said Blum. 

Moving Through The Food Web 

 And, he added, if concentrations of mercury are increasing in polar bears, which are at the top of the food chain, “this is an indication that they are also increasing lower in the arctic food chain.” 

That means human populations that rely on subsistence hunting could also be experiencing an increase of mercury exposure as well. 

How Mercury Becomes Poison 

 Relatively harmless in its inorganic state, mercury becomes extremely poisonous to humans when it is converted into methylmercury and passed up the food chain. 

Mercury in its methylated state is considered by many to be “public enemy number one,” said Blum. Its prevalence in the Arctic and potential to spread through the food chain is a very real concern and could be exacerbated by climate change. 

Recent discoveries about mercury’s biochemical properties have unlocked mysteries about the element and enabled scientists to probe deeper into the question of how a relatively inert element (mercury) can transform into a menacing poison. 

Scientists know that at times there can be extremely high concentrations of mercury in the Arctic snow pack and are working to understand where it is coming from and what unique chemical reactions take place in the Arctic that lead to rapid deposition of mercury from the atmosphere to the snowpack. 

Next Steps 

  

Sunrise on the flats near Barrow. Blum and his colleagues hope to better understand how mercury travels to and deposits in the Arctic. Photo: Joel Blum

Now that his team better understands the Arctic food web, pre-1950, the logical next step would be to examine mercury levels and nitrogen and carbon isotopes in bears from 1950 to present day, he said. 

In addition, much remains to be understood regarding mercury in the Arctic. Specifically, scientists want to better understand where it comes from, how it travels to northern latitudes, what mechanisms cause it to be deposited, and where it is converted to methylmercury. 

“We want to better understand what’s going on in the arctic mercury cycle, to see if we can help mitigate the problem,” said Blum.  —Rachel Walker

Arctic Stories: New Multi-Media Web site

Not your typical office. A research building at Barrow, AK. Photo courtesy Arctic Stories

We’re pleased to welcome Arctic Stories, the brainchild of Purdue University atmospheric chemist Paul Shepson, to the online effort to educate and inform people about arctic research and life. (In 2009, we supported Shepson and others working at Barrow, Alaska, on an international study called OASIS. Shepson headed an NSF-funded study of halogen chemistry.)

With children’s book author Peter Lourie, Shepson has built a multi-faceted Web site with NSF funding to present information on the science, wildlife, climate, and people of the Arctic.

The site features video interviews with natives and researchers like polar bear researcher Steven C. Amstrup of the USGS. It also showcases compelling photographs, and links to science institutions. In short, it’s another fantastic resource for following the ongoing work in the Arctic.

This is helpful as the public strives to understand the myriad messages about climate change, research, and more. With news stories reporting that the Arctic is warming twice as quickly as the rest of the planet, that sea ice is melting, and that species are losing habitat and nourishment, sites like Arctic Ice and ours aim to inform readers about the efforts being made to understand the science behind the phenomena.

The science is complex, designed to measure and help us understand changes in the atmosphere, land, plants and animals, human societies and water in the Arctic. To advance these goals, scientists conduct fieldwork in some of the most extreme environments on Earth–and their experiences are often as compelling as their data.

We encourage readers to check out Arctic Ice as they follow their curiosity about work in the far north.

When the ground collapses like a soufflé: Studying the effect of thermokarst on the Arctic

By Emily Stone 

This is the thermokarst failure on a stream leading into the Toolik River on the day Breck Bowden and Michael Gooseff discovered it in 2003. (Courtesy of Michael Gooseff)

Scientists Breck Bowden and Michael Gooseff were flying in a helicopter near Toolik Field Station in 2003, scouting for good field sites for river research when they spotted something peculiar. 

Unlike the crystal clear Kuparuk River nearby, the Toolik River was a muddy brown, an unusual site in the Arctic where tundra streams don’t pick up much sediment because the ground is usually frozen. The men had the helicopter fly upstream to investigate. After 40 kilometers they saw the culprit: a small stream leading into the river had a huge, narrow crater on its shore that was dumping sediment into the river. 

“It was a severe gash on what was otherwise a nondescript hillside,” said Gooseff, an assistant professor of civil and environmental engineering at Pennsylvania State University. 

The feature is what’s known as a thermokarst failure. Thermokarst occurs when ice in the usually solid permafrost melts and the land gives way like a soufflé. When this happens on flat ground, the melted water pools into a thermokarst lake. When it happens on a slope, as was the case along the Toolik, the water rushes downhill and usually into a nearby body of water and the ground slumps after it, causing what’s called a thermokarst failure. 

The helicopter landed by the gash. Bowden, a professor of watershed science and planning at the University of Vermont who is over six feet tall, was engulfed in it when he stood at the bottom. He guesses that it had formed within a few days of their arrival. 

Standing there, he remembers looking around at all the other tiny streams that led into the region’s big rivers and thinking, “It wouldn’t take many of these on the landscape to have a fairly big impact.” 

Bowden is now leading a project that includes Gooseff and 15 other principal investigators to discover what exactly these thermokarst features are doing to the landscape and river networks, and how they form in the first place. They’ve already established that there are many more of them than there were 25 years ago, the likely result of rising temperatures in the Arctic. As more thermokarst failures develop, researchers want to know how the additional nutrients dumped into rivers will affect aquatic ecosystems, how they’ll impact the plant communities that grow back after a thermokarst landslide, and how they’ll change the amount of carbon dioxide and methane being released into the atmosphere — all crucial questions in the study of climate change. 

Breck Bowden explores the thermokarst failure on a stream leading into the Toolik River on the day he and Michael Gooseff discovered it in 2003. (Courtesy of Michael Gooseff)

Downstream of the same thermokarst feature as it looked this summer when the group of researchers began their multi-disciplinary study of the phenomenon. Photo: Emily Stone

The group, which includes another couple dozen graduate students and technicians, is in the first year of a four-year, $5-million grant from the NSF’s Arctic System Science Program. They spent their first field season at Toolik this past summer picking their research sites and setting up equipment to monitor the changes happening in and near the thermokarst failures. 

Previous research by Bowden, Gooseff and some of the other collaborators established that, at least in the area around the field station, there are many more thermokarst failures than there were in the early 1980s. The group did an aerial survey of 600 square kilometers around the station and compared their observations to an aerial survey that was done in the same area around 1980. They found 34 thermokarst, two-thirds of which were new. This data doesn’t necessarily correspond to the rest of the Arctic since different soil conditions, slope and climate affect thermokarst formation, but it does suggest that the features are growing in at least one large swath of Alaska. 

The concern is that these features can have an outsized impact on the environment. 

Bowden is interested in the nutrients that are usually held frozen in permafrost — what he describes as “brown concrete” — that are released into rivers when that permafrost melts. The addition of ammonium, nitrate and phosphate means that aquatic microbes and plants have much more to eat and can flourish in areas where their populations were previously limited by a lack of food. This can dramatically alter a river’s ecosystem. 

He has set up water monitoring stations on rivers above and below thermokarst failures to compare the sediment and nutrients in the water before and after the thermokarst soil reaches it. Earlier research showed that the Toolik River thermokarst failure delivered more sediment to the river than was dumped into the Kuparuk River over the course of 18 years from a 132-square-kilometer section of watershed. 

Other researchers in the group are looking at how plants react to thermokarst failures. “We have a suspicion that what they evolve into is a shrubby community,” Bowden said, instead of the low tundra grasses that dominate the region. 

This is important because shrubs hold on to more sunlight than grasses, which warms the soil below. This can in turn release more stored carbon out of the warming soil. Additionally, warmer soil releases more nutrients for microbes to use as fuel. Microbes then release more methane into the atmosphere, which is a powerful greenhouse gas. Scientists in the thermokarst group are measuring this CO2 and methane release. 

Other researchers are looking at remote sensing and computer modeling, as well as interviewing Native Alaskan communities nearby to learn about their memories of where thermokarst have occurred in the past. 

Gooseff is taking a step back to try to figure out what causes the thermokarst failures in the first place. He has placed water and temperature sensors at various depths in and near several thermokarst features, as well as instruments above ground that measure rain, snow, sun and wind. His post doc, Dr. Sarah Godsey, set up cameras to take pictures of the thermokarsts every hour. Their goal is to be able to correlate the weather and soil data with physical changes in the permafrost and landscape. 

Bowden notes that thermokarst are not a new occurrence. Scientists have been aware of them for years, and engineers have long studied them in the context of building roads, homes and pipelines. 

“It is a natural phenomenon, but it appears to be one that is accelerating,” he said.

Emily Stone is a freelance writer from Chicago, Illinois. She spent a week at Toolik Field Station in 2009 as an MBL journalism fellow.

Pretty Cool Research

Alaskan beetle Upis ceramboides produces a non-protein "antifreeze" molecule. Photo: Kent Walters, University of Notre Dame

Researchers have discovered a new class of biological antifreeze molecules: the first that do not contain proteins. The antifreeze, extracted from a freeze-tolerant Alaskan beetle, is made of a combination of sugars and fatty acids.

Dr. Kent Walters (University of Notre Dame) and colleagues report in the Nov. 24 issue of Proceedings of the National Academy of Sciences (PNAS) the successful isolation of a freeze-tolerant Alaskan beetle’s anti-freeze molecule. The beetle from which the antifreeze was extracted is capable of surviving at -60°C (-76 F).

This discovery, which was funded by the National Science Foundation (NSF), could assist future efforts at preserving cells or whole tissues by cooling them to low sub-zero temperatures, a process known as cryopreservation.

“Potential applications for this new class of antifreeze molecules are abundant,” said Walters in a release. “In terms of cryopreservation, we may be able to increase viability and enhance survivorship of cells and tissues from other organisms under freezing conditions.”

This specific antifreeze molecule is a combination of saccharides and fatty acids. As a consequence, it is smaller than most proteins and its chemical composition could be replicated in a lab for easier commercial production. Small chains of sugars can be readily synthesized in the laboratory, making them cheaper and easier to manufacture than biologically assembled molecules like proteins.

A multitude of organisms such as fish, insects, plants, fungi and bacteria contain antifreeze molecules. Past efforts at isolating the antifreeze molecules have been unsuccessful, in part because those molecules may show up only when triggered by extreme environmental factors.

Tapestry waving in the wind

While trying to catch up on everything we missed last week, we just noticed that John Whiteman posted another in his series, “Polar Bears of Summer,” for Exploratorium’s NSF-funded outreach project, Ice Stories.  As ever, Whiteman delivers the goods from the USCGC Polar Sea, where the Hank Harlow-led team of University of Wyoming researchers are tracking and re-examining a set of bears they collared last spring.

US Coast Guard Cutter Polar Sea navigates pancake ice in the Arctic Ocean.

The ship ran into some heavy seas, leading to all personnel being restricted from going on deck. Whiteman writes that the sea ice responding to the swells was “like watching an enormous tapestry waving in the wind.” If you haven’t checked out Whiteman’s dispatches, you’re missing the boat (and the bears).

Changing Climate, Changing Patterns: An Occasional Series On The Impacts Of Warming Temperatures

 

Brant geese

A Pacific brant family on the Yukon-Kuskokwim Delta, Alaska. Photo: Jeff Wasley, courtesy U.S. Geological Survey

Warming Temperatures Affect Geese Migration

 As Alaska’s climate has warmed over the last four decades, Pacific brant geese have drastically changed their winter migration, according to a recent study in the journal Arctic. Whereas 90 percent of the population recently wintered in Mexico, today about 30 percent of the population —roughly 40,000 birds—are spending their winters in Alaska, according to the U.S. Geological Survey-led study.

“This increase in wintering numbers of brant in Alaska coincides with a general warming of temperatures in the North Pacific and Bering Sea,” said David Ward, the lead author of the study and a USGS researcher at the Alaska Science Center. “This suggests that environmental conditions have changed for one of the northernmost-wintering populations of geese.”

The study found that the migration shift appears related to the changes in availability and abundance of eelgrass, the primary food in the non-breeding season. Release of the study garnered widespread news reports of the impacts a warming climate has on species migration. In Mother Jones, Julia Witty notes that warming temperatures have well-documented effects on the abundance and distribution of many marine species, including walleye Pollock, Pacific cod, northern fur seals, and thick billed murres.

A Polar Field Services Series: Changing Climate, Changing Patterns

The field notes team plans to report a series of stories and interviews with scientists on the real-time impacts climate change has on native populations—both human and animal. The recent article by Ward et al. details the changing patterns in brant outside of the breeding season. To learn more about how climate change is altering the birds during the summer breeding season, we asked Jim Sedinger, professor at the Department of Natural Resources and Environmental Science at the University of Nevada, about his long-term research on breeding strategies of Pacific brant in Alaska, funded by the NSF.

Interview With Jim Sedinger

Polar Field Services (PFS): What makes brant geese an interesting species to study for ornithologists, ecologists, and climate scientists?

Jim Sedinger: The colonial nesting nature of brant makes it possible to study demography (survival, reproductive effort, recruitment into the breeding population, etc.), which is difficult for many other species.  Brant behavior in winter also allows following individuals in winter and spring.  Brant come out of the water following high tide each day to preen and acquire grit.  Investigators can read their uniquely engraved plastic leg bands during these periods.  In some years during the 1990s David Ward’s crews read > 14,000 bands in Mexico during winter.  Individual brant are also observed in large numbers in Humboldt Bay (Jeff Black and students) and the Strait of Georgia (Environment Canada).

Brant on the Pacific coast are dependent on eelgrass in bays and estuaries extending from Alaska to Baja, so they are excellent indicators of environmental conditions along the coast.