Arctic

the greening of the arctic

September 19, 2019

By Amber Aumiller, graduate assistant, Sustainability Office

What do you think of when you think of the Arctic? Vast glacial landscapes? The Aurora Borealis? Polar bears and melting sea ice?  Most of us are aware that global warming is rapidly heating up the Arctic, but for many of us, it’s still a relatively foreign, frosty place. Dr. Ken Tape is a scientist who’s spent his career studying the Arctic tundra’s shifting ecosystem as climate warming transforms the globe’s northernmost landscapes. He’ll be at the University of Utah on Tuesday, October 1st from 4-5 p.m. in ASB 210 to talk about “The Changing Arctic Landscape” as part of the GSCS seminar lecture series.

As an ecologist at the University of Alaska Fairbanks, Dr. Tape is interested in the interconnectedness and transformation of this unique arctic ecosystem. Born and raised in Alaska, his specific focus is on what the changes in this integrated arctic ecosystem will mean for the future. His educational background spans geology and the biological sciences. He’s published a book, The Changing Arctic Landscape, has a traveling museum exhibit (Then & Now: The Changing Arctic Landscape), and is a renowned fine art photographer.

By comparing old photographs from up to 150 years ago to today, he looks at shifts in plant and animal life from the boreal forests into the greening arctic tundra. Combining this with other environmental data, Dr. Tape’s work enriches our understanding of what is happening to the Arctic ecosystem as a once icy and inhospitable place warms to become extended habitat for an array of wildlife. He’s studied the shrubs and vegetation, moose and snowshoe hare populations, shifting snow and melting permafrost, and his most recent work focuses on beavers and hydrology.  As mini-ecosystem engineers, beavers can have a dramatic and swift influence on landscapes, and Tape points out, “very few species leave a mark so visible that you can see it from space.”[1] He uses not only aerial but also satellite imagery as part of his research looking at how these large-toothed lodge-dwellers are shaping the greening tundra, most massively via their hydrologic habitat effects. Warmer air temperatures lead to more shrubs and flowing water in the winter which provides new terrain for beavers to colonize and transform, ultimately impacting stream and riparian ecosystems and thawing permafrost.

Permafrost is continuously frozen soil, rock, or sediment that exists either below ice sheets or below an active soil layer. We know it stores carbon and methane gases, and we’re learning that global climate warming is contributing to rapid thaws in the Arctic’s permafrost.  We’ve also known about disappearing summer sea ice in the Arctic and the potential global implications, but we’re just starting to talk as a global community about what the “abrupt thaw” of arctic permafrost could mean. Some estimates predict that the quantity of global greenhouse gas released will be double that of earlier projections, a number not previously accounted for in the Intergovernmental Panel on Climate Change’s climate model report unveiled last October.

Dr. Tape’s observations of beavers as an ecosystem disturbance suggest that permafrost thaw in the Arctic could be self-reinforcing, making the thaw faster than we’ve expected. In seeking to understand what’s happening with an integrated ecosystem he’s quick to engage with geographers and historians as interdisciplinary knowledge is a meaningful way to deepen comprehension of complex systems. He isn’t one to make strong predictions of the future but prefers to his work to open the door for more questions of how the interconnectedness of these systems plays out. New knowledge about how global warming alters entire ecosystems at the northernmost parts of our planet opens up new ideas on the potentialities of the future. Aside from a faster permafrost thaw feedback cycle, the greening of the tundra could also mean new habitat for salmon, for instance. In this way, the knowledge that Dr. Ken Tape has to share is a valuable piece in the grand picture of our future on the earth.

Come learn about “The Changing Arctic Landscape” from Dr. Ken Tape on Tuesday, October 1 from 4-5 p.m. in ASB 210.  We’ll have coffee and treats for you, so bring a mug and enjoy!

[1] National Geographic, August 2019

Antifreeze Adaptations

March 6, 2018

By Bianca Greeff, Graduate Assistant.

The Antarctic snailfish, Paraliparis devriesi, named after Professor Art DeVries from the University of Illinois at Urbana Champaign, lives perhaps 700 m down and has insufficient antifreeze to cope with ice crystals. Courtesy of Peter Wilson.

Reaching temperatures as low as -89°C, Antarctica is the coldest, windiest and driest continent on the planet. The Southern Ocean that surrounds Antarctica doesn’t offer much relief for species. In the winter, the ocean surface freezes solid, doubling the continent’s size. In the summer, temperatures rise just above freezing and melt away some of the sea ice.

Despite water temperatures remaining around -1.5 to -2°C, the Southern Ocean is teeming with life.

Peter Wilson, visiting distinguished professor at the University of South Florida and associate dean at the University of Tasmania Institute for Marine and Antarctic Studies, will provide a general overview of the Southern Ocean and explain how species have adapted to survive in and around Antarctica at the GCSC Seminar Series on Tuesday, March 27, 4-5 p.m. in 210 ASB.

Over the course of millions of years, marine species have adapted to the harsh, cold water in the Southern Ocean.

“A fish from the coast of California would freeze solid like a popsicle if it was placed in the waters around Antarctica,” explained Wilson. “The fishes around Antarctica, and in the Arctic, have evolved to create these wonderfully interesting protein molecules that bind to the ice crystals and stop the crystals from growing.”

One of the species Wilson will discuss is the Antarctic toothfish (Dissostichus mawsoni). The Antarctic toothfish produces antifreeze glycoproteins that allow it to survive in the freezing waters of the Southern Ocean. The glycoprotein comes in a variety of size ranges, and can be found in all body water, not just in the blood. But Wilson suggests it isn’t the protein itself that is interesting. Rather it is the way the proteins bind with ice crystals.

Species with these antifreeze proteins can be classified as either freeze tolerant or freeze avoidant. Freeze tolerant species include those species who can handle a significant amount of freezing. Up to 81 percent of their body water can be frozen solid and these species will still survive, said Wilson.

Don Juan Pond is a small, hypersaline lake in the west end of Wright Valley. With a salinity of over 40%, Don Juan Pond is the saltiest of the Antarctic lakes and remains liquid even at temperatures as low as −50 °C. Courtesy of Peter Wilson.

Freeze avoidant species are the species who prevent the freezing of their bodily water all together. There are a few ways for species to be freeze avoidant. Some might avoid freezing by supercooling—chilling a liquid below freezing temperatures without the liquid becoming solid.

But it isn’t just Antarctic fish that have antifreeze capabilities, insects and mammals have also adapted to the cold temperatures under and on Antarctica. Some insects are able to avoid freezing completely by having gooey hemolymph (the insect equivalent to blood) that slows the formation of ice crystals. In his talk, Wilson will show how a number of species have adapted to the cold.

At the end of his talk, Wilson will indicate some of the ways humans are using this information about antifreeze proteins to transform our own lives. From producing smoother ice-cream to deicing airplanes, Antarctic species might hold the key for future innovation.

To hear more about Antarctic adaptations and Wilson’s journeys through the Pacific to Antarctica attend his GCSC lecture, “Antarctica—Fishes, Adaptations and Dealing with Ice” on Tuesday, March 27 at 4 p.m. in 210 ASB.

 

 

Cover Photo: Ross Island, with Mt Erebus in the background and McMurdo Station seen at front right.  The photograph was taken standing on about 6 feet of sea ice. Courtesy of Peter Wilson.