Effect of storm events on benthic nitrifying activity.

Area of Science:

• Environmental microbiology
• Aquatic ecosystem dynamics
• Biogeochemical cycling

Background:

• Geothermal streams receive ammonium inputs, influencing microbial communities.
• Benthic nitrifying activity is crucial for nitrogen cycling in aquatic ecosystems.
• Storm events can disrupt microbial processes in streams.

Purpose of the Study:

• To investigate the impact of storm events on benthic nitrifying activity in a geothermal stream.
• To determine the recovery rate and in situ growth of nitrifying bacteria post-storm.
• To compare in situ nitrifier growth rates with laboratory-derived rates.

Main Methods:

• Monitoring benthic nitrifying activity before and after a storm event.
• Measuring ammonium levels and other relevant water quality parameters.
• Calculating nitrifier growth rates based on the logarithmic increase in activity.

Main Results:

• Storm events caused a significant reduction in benthic nitrifying activity.
• Nitrifying activity recovered logarithmically over 10-12 days, reaching a stable state.
• In situ nitrifier growth rates (0.0075–0.0116 h⁻¹) were lower than laboratory-observed rates (0.0233–0.0990 h⁻¹).

Conclusions:

• Storm disturbances temporarily impair stream nitrification.
• Nitrifying bacteria exhibit a measurable in situ growth response following disturbance.
• In situ growth conditions in the stream environment limit nitrifier proliferation compared to laboratory settings.