December 19, 2013

Glacier Ice Worm Investigations-A Long Slow Processs

Posted by Mauri Pelto

Yes, worms really do live in glaciers and in fact, they can’t live off of them. Their scientific name is Mesenchytraeus solifugus. I first saw an ice worm in 1981 in Alaska, the number was small and they seemed insignificant overall. In 1984 I began working in the North Cascades of Washington, and Bill Prater (inventor of the snowshoe with crampon attached) told me I would see millions, and he was correct. In the evening and night hours ice worms feed primarily on the surface of snow on glaciers, and to a much less degree, on bare ice. During the day, ice worms hide out beneath the surface of the glacier, avoiding any sunlight. We have undertaken annual ice worm counts on Sholes Glacier for twenty years. They move slowly and are out only in low lights, which does not make for exciting video, as seen below, but that is reality. On Suiattle Glacier in 2002 we found a density of ~2600 ice worms per square meter. With an area of 2.7 square kilometers, this represents somewhat over 7 billion ice worms on this glacier.
In 2003, we sat at the edge of the Sholes Glacier looking at the glacier covered Mt. Baker volcano waiting for the sun to set. After sunset we counted the ice worms on the glacier. There were close to 1000 ice worms per square meter right up to the glacier margin. By the time we had traveled 10 meters from the edge of the glacier onto seasonal snowpack almost no ice worms existed on the snowpack, within 30 m we could not find a single ice worm. This is true even in cases where the snowpack adjacent to the glacier survived the summer. Thus, the ice worms need the permanent snowpack of glaciers to survive.

In a joint project with Oregon State in 1994 we collected Ice Worms for DNA analysis, they did not find differences between ice worms from various glaciers. In 2002 In a joint study with Clark University the Ice Worm genome was sequenced. In 2011 we joined Queens University in a study of ice worm anti-freeze proteins (AFP) which help keep them from freezing solid. These AFP’s inhibit the growth of ice by lowering the freezing point and coating ice molecules. This facet is seen in other organisms that inhabit cold environments, more details on ice worm AFP from Napolitano et al (2003). Queens University was examining the ability of the AFP’s to suppress the melt temperature of water for transplant surgical procedures. Ice worms are a critical part of the glacier ecosystem in the coastal ranges of the Pacific Northwest. Glacier ice worms only inhabit glaciers from southern Alaska’s coastal ranges through the Coast Ranges of British Columbia, the Cascades of Washington to the Three Sisters of Oregon and the Olympic Mountains. The Three Sisters and Mount Hood areas is south of the Cordilleran Ice Sheet limit, indicating that this ice sheet cannot be the only dispersal method for ice worms. It is also noteworthy that ice worms are not found in the interior ranges of British Columbia or in the Rocky Mountains, which is the interior side of the Cordilleran Ice Sheet. The ice worms are associated only with temperate climates. Ice worms are tough too, surviving the Mount Saint Helens eruption in the firnpack of the newly redeveloping glacier on the mountain. The most likely means of populations spread dispersion is birds, the Rosy Finch is the bird most commonly seen feeding along the surface of the glaciers. For further details note our Ice Worm Research Project page.