Icebound

MYSTERIES OF THE ICE WORM

by Emily Mount


IT WAS MIDNIGHT ON THE HARDING ICEFIELD. A lone figure swooshed over the ice on skis, intent on reaching his destination. Roman Dial was defending his title in the 1984 Alaska Wilderness Classic, an epic 150-mile journey across the Kenai Peninsula. Dusky summer twilight clung to the horizon, casting enough light for Dial to notice something odd.

He slowed, pausing to stare at the snow between his skis. “I saw what looked like little pieces of black thread all over the glacier,” Dial said. Falling to his knees, Dial examined the bizarre creatures. With a thrill, he realized they were ice worms. “They looked just like skinny earth worms but in miniature. There were millions of them.”

Today a professor of biology and mathematics at Alaska Pacific University, Dial has spent years studying the mysterious glacier worm he encountered decades ago. This tiny worm may hold clues to many intriguing puzzles, from how to ward off frostbite to understanding extraterrestrial life.

Discovered in Glacier Bay in the late 1800s, ice worms (Mesenchytraeus solifugus) are hair-like worms with segmented bodies and a tiny mouth pore. Every summer evening, they wriggle onto the surface of many Alaskan glaciers to feed on pollen and red algae. Armed with setae (tiny hair-like bristles),

worms propel themselves as quickly as 10 feet per hour. They live up to their Latin name solifugus, or “sun avoider,” by burrowing a few feet into the glacier at daybreak. Nestled between ice crystals, they absorb enough sunlight through their dark skin to keep from freezing solid before squirming back to the surface at night.

North America’s retreating ice sheets fractured ice worms into three distinct populations, from Alaska’s Chugach mountains to glaciers as far south as Oregon. Though enjoying a large geographical distribution, ice worms are unable to disperse over long distances unaided. Dial and his colleagues have found a surprising genetic link between ice worms in southeast Alaska and Vancouver Island, 1,200 miles away. They point to birds like snow buntings and gray-crowned rosy finches as the primary dispersion mechanism. “These birds are eating ice worms,” Dial says. “It’s possible that a cocoon, which is a sticky little egg case, might get stuck on the beak or feet of a bird migrating in the fall, and together they get quickly blown across the Gulf of Alaska.”

Ice worms are tiny. This one from La Perouse Glacier in Glacier Bay National Park is barely visible on a fingertip.

Beyond their intriguing genetic puzzles, ice worms have sparked interest with the National Institutes of Health, National Science Foundation, and U.S. military due to their ice-loving lifestyle. Under freezing conditions, most animals slow their metabolism to conserve energy, but an ice worm’s metabolism speeds up. Researchers have identified the enzyme causing this unusual physiological phenomenon and are trying to replicate the process in bacteria and flies. Someday, this could help preserve human transplant organs in cold storage and even repel frostbite.

Thriving in conditions most species find deadly, ice worms are classified as an extremophile. Other extremophiles include bacteria in Yellowstone’s geothermal hot springs and tube worms in deep ocean hydrothermal vents. NASA believes extremophiles hold evolutionary and adaptation clues for environments that are hostile to life as we know it. “If we are going to look for life on other planets,” asks Dial, “what should we be looking for?” Ice worms and their red algal prey might provide insight into the colors of extraterrestrial life. “If you’re going to live on an icy planet or moon, you might be red or black, which are good colors to absorb solar energy and keep you warm.”

Most of us do not know ice worms for their cutting-edge research, but from the (in) famous poem “The Ballad of the Ice-Worm Cocktail,” penned by Robert Service around the turn of the twentieth century. Service wrote: “Their bellies were a bilious blue, their eyes a bulbous red; their backs were grey, and gross were they, and hideous of head. And when with gusto and a fork the barman speared one out, it must have gone four inches from its tailtip to its snout.” This poem has plagued the validity of ice worms ever since, with many people (including Dial before his Harding Icefield experience) believing them whimsical, fictitious beasts. Some Alaskans honor the ice worm, however. Cordova holds an annual Iceworm Festival featuring a parade with a 100-foot-long ice worm, the crowning of Miss Iceworm, and a cake decorating competition.

Though today there are more ice worms than humans on the planet, their glacier habitat is rapidly shrinking. Like other species struggling with the effects of climate change, this tiny worm’s fate rests (literally) on ice. In the future, Dial believes, “Ice worms may turn out to be important for humans. But even if they don’t, they are still the most charismatic animals living on Alaska’s glaciers and icefields, and for that we should celebrate them.”


Frequent contributor Emily Mount recently married while researching this article. No ice-worm cocktails were served at the festivities.

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