MACROINVERTEBRATE RECOVERY RATES FROM SIMULATED STREAMBED DISTURBANCE ACROSS A GRADIENT OF ACID MINE DRAINAGE IMPAIRMENT
In Appalachia, acid mine drainage (AMD) causes stressful conditions for stream biota, including elevated dissolved metal concentration and low pH. Macroinvertebrates in AMD impaired streams are strongly structured by the conditions, which result in low diversity and mostly tolerant taxa; these impaired streams may respond differently to additional stressors such as large flooding events which cause streambed disturbance. We hypothesize that impaired streams will respond differently to disturbance compared to recovered and unimpaired streams. Riffles were physically disturbed with rakes in AMD impaired streams (N=2), recovered streams (N=3), and unimpaired streams (N=2); macroinvertebrates were sampled immediately before disturbance and 5, 10, 15, and 30 days afterwards. Macroinvertebrates were identified to family and by functional feeding group. Taxonomic richness was higher in recovered and unimpaired sites before disturbance, 10 days, and 15 days after disturbance (p= 0.0522, 0.074, 0.0425, respectively). There was no significant difference 5 days or 30 days after. This indicates all sites responded similarly shortly after disturbance, but unimpaired and recovered sites returned to pre-disturbance richness, while impaired sites remained below pre-disturbance richness.
Mariah Thrush Hood (Primary Presenter/Author), Ohio University, email@example.com;
Kelly Johnson ( Co-Presenter/Co-Author), Ohio University, firstname.lastname@example.org;