Meanings of column headers: Mesocosm -- numeric idendifier for each mesocosm Date -- date sample was taken Day -- number of days elapsed since the experimental beginning Depth -- water depth in mesocosm in centimeters Temp -- water temperature in mesocosm in degrees Celsius Cond -- specific conductivity of water in mesocosm in microsiemens per meter ** note that gaps in water condition data indicate that mesocosm was dry during that sampling date