Rare, Cold-water Aquatic Macroinvertebrates in Glacier National Park: Vulnerability, Resilience, Persistence and Sustainability

Collaborators: Joe Giersch (USGS), Doug Peterson (USFWS, Helena), Chris Downs (NPS, Glacier National Park), Dr. Ric Hauer (University of Montana)

Lednia tumana, Reynolds Creek spring, Logan Pass, Glacier National Park, MT, Aug. 2009.As global climate change alters water temperatures, streamflow patterns, and fire regimes, sensitive aquatic invertebrate species are likely to be adversely impacted due to their relatively narrow range of habitat requirements and high degree of specialization in high elevation habitats. Glacier National Park (GNP) has been a primary example of the impacts associated with global climate change in the conterminous United States. Regionalized climate models indicate that GNP will likely see earlier and more rapid snowmelt in the spring, and warmer and drier summers leading to late summer drought and continued loss of Glacier Park’s glaciers, snowfields and perennial streams. Glacier is home to numerous rare, cold-water-obligate, aquatic invertebrate species with limited distributions, including several species of caddisflies (Trichoptera: Rhyacophilidae and Apataniidae) and a groundwater dwelling amphipod (Stygobromus glacialis). Of particular interest is a rare stonefly known as the mist forestfly, or the Lednian meltwater stonefly (Lednia tumana), which is believed to be endemic to a very limited distribution of springs/streams in the Rocky Mountain Cordierra, particularly GNP.

The U.S. Fish and Wildlife Service is currently conducting a status review of L. tumana in response to a petition to list the species as endangered under the Endangered Species Act. The only location records available at the time of the petition for listing occur in GNP and Waterton Lakes National Park in Canada, which together form Waterton-Glacier International Peace Park. The listing cites global climate change as the primary threat to the persistence of this species. In order to assess the current status and potential risk that climate change poses to the distribution and persistence of these species, the USGS-NOROCK Aquatics Research Program in GNP and the UFWS are undertaking a broad survey of high elevation waters in GNP with the potential to support these species. Most often, these species are associated with high-elevation snow-melt or glacier-melt streams, or high elevation spring systems fed by late season snow and glacier-melt. Their density generally decreases rapidly in a downstream fashion, suggesting a remarkably restricted set of habitat requirements associated with cold water habitats.

The overall objective of this study is to evaluate the current status and changes in the distribution and abundance of L. tumana and rare and sensitive macroinvertebrates associated with alpine glacial/snowmelt habitats in GNP, and to evaluate potential impacts of climate change on these species and critical habitats. Of particular interest is the effect of climate driven shifts in thermal regime on macroinvertebrate assemblages along the stream gradients of the alpine zone, as well as potential hydrological impacts resulting from climate change (i.e., stream systems changing from perennial to ephemeral, increased winter flooding etc.).

Muhlfeld, Clint C, J. Joseph Giersch, F. Richard Hauer, Gregory T. Pederson, Gordon Luikart, Douglas P. Peterson, Christopher C. Downs, and Daniel B. Fagre. 2011. Climate change links fate of glaciers and an endemic alpine invertebrate. Climatic Change Letters. DOI 10.1007/s10584-011-0057-1

For more information contact:
Clint Muhlfeld