Within the last several years, didymo has invaded a number of locations in the Northeast United States. I am interested in determining where didymo exists and understanding if there are biogeochemical explanations for the recent invasion. I would like to quantify the extent of the blooms (biomass accrual) and to understand the impact of the blooms on the physical template of the streams (seston quality and transport), the biogeochemical implications of the blooms (nutrient cycling) and the effects on the higher trophic communities of macroinvertebrates and fish.