February 22, 2006
Tiny Ice Worms Could Reveal Life on Other Planets
PARADISE, Wash. (AP) - A tiny worm that lives in glaciers and snowfields is drawing attention for what it could reveal about life on other planets.
The ice worm inhabits glacial regions in the coastal ranges of Alaska, British Columbia, Washington and Oregon. The odd creature easily moves through ice, is liveliest near the freezing point of water and dissolves into a goo when warmed.
There's been increased interest in ice worms and other animals whose glacial habitat could disappear within the next 50 years due to global warming.
National Geographic funded one of the first field surveys to focus on ice-worm ecosystems.
NASA last year provided $200,000 to explore the worms' cold tolerance and what it might say about the possibility of life on Jupiter's icy moons and other planets. That work could also improve cold storage of organs and tissues for transplantation.
"They're kind of hot right now," said Ben Lee, a senior at the University of Puget Sound who with roommate Dave Eiriksson recently trekked up Mount Rainier's slopes to uncover the worms.
Lee, 23, chose ice worms for his biology thesis because they haven't been studied much - and they provided an excuse to get out in the mountains. He spent last summer gathering specimens from glaciers across the Olympic range.
Lee has also discussed the worms with biologists Dan Shain and Paula Hartzell.
Shain, a professor at Rutgers University in Camden, N.J., first encountered ice worms during a 1995 fishing trip to Alaska, where he saw them on display at the Portage Glacier visitor center outside Anchorage.
He has since gotten money from National Geographic and NASA for his studies on ice-worm physiology.
The NASA project focuses on a key enzyme that regulates the worms' energy cycle.
Organs harvested for transplant deteriorate as the cells' energy stores are depleted, he said. Examining the ice worms' metabolism may lead to drugs or chemical solutions that could keep organs alive longer.
Hartzell worked with Shain and has surveyed more than 80 glaciers.
She's writing a book on the peculiar community of snow fleas, nematodes and spiders that dwell on the ice. As the largest invertebrate, ice worms dominate this frozen world.
Hartzell believes the worms travel through tiny fissures in the ice, but other scientists have suggested the worms secrete a substance that melts a path, like a warm knife through butter.
The worms can boost their cells' energy production when the temperature drops, Shain discovered. "It's equivalent to putting more gasoline in your tank," he said.
They also have cell membranes and enzymes that function and stay flexible in temperatures where most animals' cellular processes creak to a halt.
The downside is extreme sensitivity to heat. At about 40 degrees F, the worms' membranes melt and their enzymes go haywire.
Around sunset during warm weather, the black worms are hard to miss as they swarm to the surface to feed on algae, pollen and other digestible debris.
"In some places, they're so thick you can't step without killing tons of them," Lee said.
Before dawn, the worms retreat back into the ice. Their species name, solifugus, means sun-avoiding.
In winter, when algae can't grow and snow blankets the surface, Lee suspects the worms stay deep inside the ice, perhaps going dormant.
In an attempt to root them out, he and Eiriksson recently followed a snowshoe trail that wound steeply through stands of subalpine fir half-buried in pillowy drifts. More than 600 inches of snow fall in the area in an average year.
They dig in an area below McClure Rocks at an elevation of about 7,000 feet. It's not a glacier, but the depression is filled with snow year-round and in the summer worms are regularly spotted there.
"I found one!" Lee shouts after the two have dug a 12-foot hole
"I can't believe it," he said, grinning. "The elusive ice worm."
In each hand was a chunk of snow and what looked like a dark thread. The shorter of the two worms corkscrewed slowly, then froze.
Lee touched the tiny spiral and it snapped. The outside air temperature of about 20 degrees was apparently below the ice-worm survival point.
"Oh well," Lee said. "It's still pretty exciting."
Information from: The Seattle Times, http://www.seattletimes.com