End of experiment flume water chemistry Costello, Kulacki, McCarthy, Tiegs, and Cardinale. 2018. Ranking stressor impacts on periphyton structure and function with mesocosm experiments and environmental-change forecasts. PLOS One. doi: xxx Contact information: David Costello Kent State University dcostel3@kent.edu Context: Water chemistry (pH, nitrate, ammonium, and soluble reactive phosphorus) at the end of the flume mesocosm experiment. Flume mesocosms were either under control conditions or exposed to one of six stressors along a concentration gradient (elevated temperature, extinction, sediment, nitrogen, phosphorus, or salt). Temporal coverage: The experiment was initiated on October 24, 2011 and ended on December 20, 2011. Data are from samples taken December 19 and 20. Geographic coverage: Experiment was completed in the Cardinale Lab experimental flume facility at the University of Michigan (Dana Building, University of Michigan, Ann Arbor, MI, USA). Stream water and algal inoculum for the streams was collected from the Huron River at the University of Michigan Nichols Arboretum in Ann Arbor, MI, USA (42°16′59.32″ N, 83°43′27.89″ W). Data codes: Temp - treatments with elevated temperature Ext - treatments with altered algal inoculum to simulate extinction. Inoculum in control streams had 43 total taxa Sed - treatments with elevated sedidment Nitrogen - treatments with elevated nitrogen Phosphorus - treatments with elevated phosphorus Cl - treatments with elevated salinity (NaCl) Control - flumes with no stressors added SRP - Soluble reactive phosphorus Attributes: Name Definition Type Units FLUME Unique flume ID Discrete TREAT Stressor treatment of flume Discrete pH Flume water pH Continuous Standard pH units NO3 Nitrate nitrogen concentration Continuous µg/L NO3-N NH4 Ammonium nitrogen concentration Continuous µg/L NH4-N SRP SRP concentration Continuous µg/L P Detection limits: NO3 - 20 µg/L NH4 - 20 µg/L SRP - 5 µg/L