Effect of storm events on benthic nitrifying activity.

Storm events resulted in a marked reduction in the benthic nitrifying activity of a stream receiving geothermal inputs of ammonium. Subsequently, nitrifying activity demonstrated a logarithmic increase until a stable activity was reached 10 to 12 days after the storm event. The rate of increase of poststorm nitrifying activity was used to calculate the nitrifier growth rate in situ (0.0075 to 0.0116 h) which was lower than the growth rates observed for laboratory cultures of nitrifying bacteria isolated from the sediments (0.0233 to 0.0990 h).