The 11 study springs will be sampled at the spring eucrenal (source) and hypocrenal (downstream, >25m from source). BMIs will be collected as composites of five 120 cm2 quadrats in a 250μ net by roiling the substrate within each quadrat to release BMIs and allow them to drift downstream into the net. In each spring reach, BMIs will be collected in each quadrat along five transects at 3 m intervals and oriented perpendicular to the thalweg. Quadrats will be sequentially placed along transects at springbrook center, right bank, center, and left bank. Samples will be preserved in 90% ethyl alcohol and returned to the DRI Aquatic Ecology Laboratory for processing and to Rhithron Laboratory (Missoula, MT) for identification. The structure of BMI communities will be determined from a total of 300 individuals that are randomly selected, identified, and enumerated (Vinson and Hawkins, 1996). Habitat disturbance at each reach will be quantified using methods of Sada and Pohlmann (2003).

Approved