Cold Clues for a Hot Climate

Guarded by a moat of ice and nearly barren, Antarctica is a tough sell. It’s a piercing, bone-freezing cold most of the year. Only a few sturdy life forms thrive on or near the frigid real estate.

But for the same reasons Antarctica is so hostile to most life, it’s an ideal spot for Thorsten Dittmar’s research.

The assistant professor of oceanography specializes in studying the flow of tiny carbon-based molecules dissolved in the seas to better understand the overall global carbon cycle, one of the most important factors in climate change. The more carbon that gets stowed away in oceans—and in forests and soils—the less there is available for hooking up with oxygen to form carbon dioxide, a greenhouse gas that traps heat in the atmosphere.

But it’s a complicated picture. An abundance of carbon sources, including plants, animals and the burning of fossil fuels, muddies the picture of how exactly carbon cycles through water, soil, forests and air.

What excites Dittmar about Antarctica is its lonely life. In theory, sparse creatures—an emperor penguin here, a leopard seal there—when they die and decompose don’t contribute much to the carbon in the nearby ocean.

And on top of the paucity of land life, Antarctica features another unique trait that makes it an ideal natural laboratory. The ice-blanketed Weddell Sea that carves into the belly of the continent is one of only two known places in the world where surface water sinks into the deep ocean, taking massive amounts of carbon with it and sequestering it for hundreds of years away from the atmosphere.

This plumbing of carbon into abyssal waters, some research has suggested, plays a significant part in the carbon cycle. From November 2004 to January 2005, Dittmar spent a below-freezing Antarctic summer sampling the waters to find out just how significant the sea really is to the global climate.

His preliminary findings have surprised even him. Dittmar found that a portion of the deep-ocean carbon molecules come from high-heat sources, such as deep-ocean hydrothermal vent communities or the burning of organic material, two sources which occur no where near the white continent. His first round of results have been accepted by the journal Marine Chemistry for publishing this fall.

—C.S.

Tracking Down A Sole Survivor

For 18 years, David Redfield has been counting down.

Since retiring from the education faculty in 1988, Redfield had become an avid bird- and mammal-watcher, and had set a goal to see a representative of every mammalian family possible.

This May, he landed in Laos with just seven representative animals left to see out of 147 families known to science. If he succeeded, he would become the first known Westerner to see and document the elusive Laotian rock rat (Laonastes aenigmamus) alive. Perhaps the only survivor of a family whose other members went extinct 11 million years ago, the dark-gray, furry critter had been dubbed a “living fossil.”

Redfield and Thai wildlife biologist Uthai Treesucon set traps in several different locations in remote limestone outcroppings—the rock rat’s habitat. With a bit of sticky rice and luck, kha-nyou (pronounced “ga-noo”, the animal’s local name) got snared near Doy, a small central Laotian village, in a trap made of bamboo and string.

Redfield’s team brought the animal back to the village to capture the first photos and video of a live rock rat. Once stateside, he contacted Research in Review for help in bringing the images to the attention of scientists.

Mary Dawson, curator emeritus of vertebrate paleontology at the Carnegie Museum of Natural History and primary author of the paper in Science (March 10, 2006) that identified the rodent as a living fossil, reviewed the footage and confirmed the images are in fact those of Laonastes. Dawson lauded Redfield’s accomplishment and called it “extremely important scientifically.”

Most striking was the animal’s gait: it waddled like a duck. Thanks to the video, Dawson said some scientists have dropped the “rat” reference and are now calling the surprisingly docile animal a duck-footed rock squirrel.

Redfield’s and Treesucon’s images, hosted on this magazine’s Web site, zipped around the world and attracted the attention of major media outlets, including the BBC and National Geographic News. The site racked up more than