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Students Probe Peculiar Ice Worms in Alaska's Glaciers

Hillary Mayell
for National Geographic News
January 28, 2002
 
Millions of students around the world are getting ready to take a virtual expedition to the glaciers of Alaska in the hope of unraveling the mysteries surrounding one of Earth's most peculiar creatures, the ice worm.

"Worms occupy the most diverse niches on the planet," said Daniel Shain, an evolutionary biologist at Rutgers University. "They live near hydrothermal vents in the ocean at temperatures that can exceed 100 degrees Celsius (212 degrees Fahrenheit), and they're living in ice on Alaskan glaciers at zero degrees Celsius (32 degrees Fahrenheit). That's about as extreme as you can get."





Shain, one of the few scientists in the world studying ice worms, is participating in Frozen World, the 13th expedition of the Jason Project. The expeditions take students on the "ultimate field trip," allowing them to conduct field work, participate in experiments, and communicate with scientists in real time using satellites and Internet technology.

"Our mission is to spark a lifelong passion for science and technology in students," said Tim Armour, executive director of the Jason Foundation of Education. "The focus of this year's expedition is really the polar regions. We came to Alaska because many of the leading indicators of climate change can be seen in both the Arctic and Antarctic."

Students and scientists will be working on glacier ice core studies—"aging the glaciers, studying their advance and retreat, mostly retreat right now, and the science of why and how ice core sampling is done," said Armour.

Other research being conducted during the two-week expedition, which runs from January 28 to February 8, includes studies involving plant and animal life, ocean circulation, and atmospheric measurements. Laced throughout the program is the human cultural aspect—exploring how people have adapted to the environment.

"And then there's ice worms, which could turn out to be hugely important," said Armour.

Learning how ice worms evolved, and what adaptations they made to survive in such extreme conditions, could lead to breakthroughs in space travel, advances in tissue preservation for organ transplants, and insight into the possibility of life on other planets.

New Look at Ice Worm

George Frederick Wright, a glacial geologist and theologian, reported finding ice worms on Muir Glacier in southeast Alaska in 1887. But the intriguing creatures basically disappeared from the scientific radar screen for more than 100 years. There have been a few scattered scientific reports over the years, but no one has studied them in-depth.

Shain first learned about the existence of ice worms from a placemat in a restaurant in Alaska. "I was in Alaska on a trip with my Dad, and we went out to eat," he recalled. "They had a little blurb on ice worms, and like most people, I thought it was a big joke."

A couple of days later, Shain went to the Portage glacier visitor's center, which had some actual ice worms. "One of the women working there was extremely enthusiastic about them and sent me about 50, and it all started from there," he said.

A year and a half ago, Shain spent the summer trekking, boating, and camping across Alaska's coastal glaciers to find out everything he could about the distribution, habitat, and life cycles of ice worms. The National Geographic Society funded the trip.

"Ice worms are just remarkable creatures," said Shain. "You could be walking along a glacier at around 7 at night and the glacier is perfectly white. At around 7:30, there are so many ice worms coming up to the surface that they change the color of the glacier to a sort of black plaid, as if you had put thousands of black threads on a white surface.

"You can't move without stepping on hundreds of them," he said.

"Dark Threads in the Ice"

The coastal glaciers that serve as ice worm habitat extend from Mount Rainier in Washington State to Alaska.

Ice worms, which are a relative of the common earthworm, have no eyes, so they don't see images, but they respond to light and dark. At a little less than an inch long (one to two centimeters), they are often described as looking like pieces of dark thread in the ice.

They have big mouths, said Shain, and their primary food source is the red algae that grows on glaciers. Their ideal temperature is zero degrees Celsius (32 degrees Fahrenheit); at 5 degrees Fahrenheit they start to disintegrate.

They spend their days burrowing up and down through the ice. "They definitely operate on some kind of Circadian rhythm," said Shain, "moving up when it's dark and down when it's light."

Ice worms propel themselves using setae, extremely small bristles that protrude from the sides of their bodies. Wiggling through fractured ice and snow crystals, they burrow as deep as three to six feet (one to two meters) beneath the surface of the ice.

They can live in colonies of a few hundred thousand to 20 million, covering an area as large as 30 acres. No one knows how long they live. Beyond the occasional bird or two, the only threat to their existence may be global warming.

"Alaska's coastal glaciers are right on the edge, at about 32 degrees Fahrenheit, and most are retreating," said Shain. "If it gets any warmer, they're going to start melting even more quickly. As their habitat goes, so too will the ice worms."

Classroom Science

The ice worms have a very large pore on the top of their heads; its function is unknown, although the worms may use it to excrete a mysterious substance. Some other worms have head pores, but these pores tend to be smaller and situated on the back of their heads.

"We don't really know what they may be excreting or what the purpose might be," said Shain. "One idea is that it could be some kind of mucous to protect them from drying out or maybe provide lubrication through the ice. Another possibility—you have to just throw ideas out there in science—is that it could be salt to help melt the ice in front of them."

It's this trial-and-error, one-idea-then-another aspect of science that the Jason Expeditions are able to convey to students through their interactive programs.

Watch Jason highlights on television in the United States on the National Geographic Channel, January 28 to February 2 and February 4 to 8 from 5-6 p.m. ET/PT. The Frozen World expedition can also be followed on the Jason Web site.
 

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