Ice Worm Tunnel

Peggy and I have been going “ice worming” every week for the last month or so. It’s part of an ongoing project that I am involved with that's studying the ecology and evolution of ice worms.

Ice worms are small, dark colored relatives of earthworms, known only for sure to live from northern Oregon to Alaska, with some distant relatives living near Bomi in eastern Tibet. In Alaska and Washington State they have been studied in the summer as well as in the lab. During the summer they are common on glaciers near, and slightly below, firn line, especially at night. They are about half an inch long at most in the Alaskan populations I’ve seen, but they are bigger and more numerous in Washington State and British Columbia.

In summer they come swarming to the surface in huge numbers on some glaciers, coastal ones mainly. The glaciers draining the Harding Icefield can be thick with them below about 4,000 feet above sea level, but we have never seen them in the Alaska Range, or on the Matanuska, or in the Wrangells. There’s a bounty on them in the Alaska Range, so if you have GPS coordinates for Alaska Range populations, let me know. In Chugach State Park I have found them on the upper Eklutna and Whiteout Glaciers and Paul Twardock saw them on the Eagle Glacier near APU's Nordic Center. We looked on Flute Glacier, but it was a bad day for them, and we found none.

A good paper on ice worm behavior is by Dan Shain of Rutgers University and a handful of his students, entitled “Distribution and behavior of ice worms (Mesenchytraeus solifugus) in south-central Alaska" published in 2001 in the Canadian Journal of Zoology, Vol. 79, pages 1813-1821. He’s my collaborator on this project. My job this winter is to track their location as winter progresses. Until yesterday they were active on the surface. Yesterday with six inches of new snow and at temperatures near their lower lethal limit (~20 F) we found only dead ones on the surface of glacier ice where last week they’d been actively moving about.

There have been other interesting discoveries: like last week (and a couple years ago) when APU graduate student Melissa Becker and I saw worms crawling off the glacier ice, atop new, fresh snow over rocks. During our visits in October and November when the worms were out they were out at 2:00-5:00 PM, too. I expect that they were out all day.

Anyway, we’re getting some satisfying exploration each week out at near Byron Glacier, like inside this tunnel that penetrates a big avalanche cone that's actually a micro-glacier: