ARCUS 15th Annual Meeting and Arctic Forum 2003

Glacier Macroinvertebrates: A Mystery to be Lost

Paula L. Hartzell^1
1Biology, Clark University, 950 Main St, Worcester, MA, 01610, USA, Phone 508-421-3775, phartzell@clarku.edu

Glaciers in the Pacific Northwest of North America provide up to one third of stream flow during late summer-early fall dry months, yet the chemical and biological processes of glaciers, and their role in the larger environment is little understood. As many of this region's glaciers are extremely sensitive in response to climate change, and their biota generally limited in dispersal ability, their biota offers both an unique opportunity at monitoring climate change effects, study of ecological and evolutionary processes, as well as a dangerous loss of diversity before it has even been discovered.

The purpose of the 2002 Field Season was to increase understanding of our cryo-ecology by performing an initial baseline inventory of macroinvertebrates living in glacial snow and ice of the North Cascades, Washington. The study included collection of an initial type collection along with pertinent biological and physical contextual data; identification and inventory of specimens; and limited analysis for preliminary statements of spatial and ecological distribution of identified taxa. Dominant taxa included ice worms (Mesenchytraeus solifugus) and Collembola. Newly species of Collembola were identified belonging to Isotoma (Myopia), Agrenia, and Isotoma (Desoria). A surprisingly wide variety of other macroinvertebrate taxa were observed and collected in smaller numbers.

Distribution of Collembola species suggests that historical connections (specifically time since isolation) are more important than size of glacier in determining species composition at this scale, more reminiscent of aquatic communities than terrestrial. Species distribution poses interesting north-south differences, with greater diversity to the north. Morphological and particularly molecular (28S rDNA) differences between North Cascades and Alaskan ice worms appear to represent significant differences, although further sampling is needed. Best fit model predictors for macroinvertebrate density included time of day, weather, percent dirt cover (during daylight hours), and substrate (pool versus snow-stream versus avalanche-ice).

Long term monitoring, incorporation of native knowledge, and recognition of potential management concerns is necessary in order to capitalize and/or protect these biotically diverse resources before they are (potentially) lost. Work beginning in 2003 will include measurement of microbial communities, description of new taxa, phylogenetic description and analysis, carbon transport and cycling, and a larger regional scope for sampling (Alaska, Yukon, British Columbia, Washington).

(Note: Poster presentation will include landscape and microscopy photography, as well as computer-generated molecular illustrations.)

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