The Case of the Mystery Mussels: Backcountry Ice Skating and a Sense of Wonder
“Where did that come from?” my six-year old daughter asked, pointing to large shell poking out of the ice. We were skating up Jim Creek on a recent, chilly and nearly snowless Sunday afternoon. We’d started our adventure from the confluence of the Jim and Knik Rivers, near Great Land Trust’s 800 acre Mud Lake conservation project.
It was the first of many freshwater mussel shells we saw that sunny afternoon, prompting questions and speculation from the kids about how certain shells came to be lodged in the ice mid-stream and how others became piled up in little caches at the river’s edge. Did a bird eat that one and then drop it’s shell from mid-air? Was the pile-up the work of river otters? Where do the otters go during these months when the river is frozen solid?
We adults had questions of our own: We knew freshwater mussels are in decline globally because they are sensitive to changes in environmental conditions and easily bio-concentrate contaminants, but how common are freshwater mussels in Alaska? How many species exist this far north? Are they easier to spot in winter when the ice holds shells at the surface and leaves are absent from the shoreline?
At home later I learned only one species of freshwater mussel occurs this far north in Alaska: Anodonta beringiana, the Yukon floater. As its Latin name suggests, A. beringiana is found on both sides of the Bering Straits. Today, its distribution provides clues to how former Pleistocene drainages were connected. These mussels are limited to lakes, ponds, sloughs, slow-moving streams, and rivers with very good or pristine water quality. I also learned that mussels have a parasitic stage, thus are totally dependent on specific fish species, which include sockeye salmon, Chinook salmon and threespine stickleback.
That Sunday afternoon on the river we’d expected to have a fun family adventure of the kind that feels unique to Alaska, with alpenglow gracing the mountains slopes and glaciers in the distance. The ice was mostly smooth with the exception of patches of fine grit blown from small bluffs at the river’s edge and other areas where leaves and alder cones lay frozen on the surface. The skating was superb and the kids were excited to be exploring the path of the winding river in their backyard wilderness.
What we had not expected was to discover the hidden treasure of mussel shells and to learn so much about this little known Alaska animal. “Where DID that come from?” There is so much to learn about the world around us; so many adventures to have; so many reasons to conserve our natural areas for present and future generations.
A partnership between the Great Land Trust and Eklutna, Inc., the Mud Lake conservation project helps keep the waters of the Jim, Mud and Swan Lake area pristine for Yukon floaters, Coho Salmon and other wildlife. It also helps ensure we have places for fun family adventures and exploration in our backyard wilderness.
Evie Witten was a founding member and the first Executive Director of Great Land Trust, from 1995-2000. She has a diverse background spanning forest and arctic ecology, work with indigenous peoples, and non-profit management. Most recently Evie served for 10 years as Deputy Director of The Nature Conservancy’s Canada Program, focused on large-scale conservation agreements, sustainable forestry, community empowerment and conservation finance. She holds a Master of Forest Science degree from the Yale School of Forestry. She lives in Anchorage with her husband, Rand Hagenstein and their six-year old daughter, Neve.