Is “rock snot” (Didymosphenia geminata) in Grand Teton National Park?

Once only identified in nutrient poor waters, Didymosphenia geminata, a microscopic single-celled freshwater diatom, has been expanding it's native range and is occurring more frequently in nutrient-rich streams and rivers.  The invasive tendencies of D. geminata are greatly altering physical and biological conditions in streams and rivers; the stalk material that D. geminata produces has the potential to cover up to 100% of stream substrate with a thickness of up to 20 cm.  We conducted a survey of D. geminata in Grand Teton National Park, Wyoming in summer 2008.  We found and confirmed D. geminata in 7 streams including; Phelps Lake Outlet (1.5x10⁸ cells/m²), Taggert Lake Outlet (2.4x10⁷ cells/m²), Phelps Lake Inlet (2.1x10⁶ cells/m²), Jenny Lake Outlet (8.4x10⁵ cells/m²), Flat Creek (2.9x10⁷ cells/m²), Leigh Lake Outlet (1.3x10⁴ cells/m²), and Fish Creek (9.2x10⁵ cells/m²).  We found a trend of D. geminata presence in lake outlet streams and high traffic areas; areas where people had direct access to the stream or highly traveled areas (bridges, roads, trails, etc.).  In fact, four of the seven streams where D. geminata was found are lake outlet streams, and all streams were noted as high traffic areas (no less than 10 people present at the stream).