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Meiofauna increases bacterial denitrification in marine sediments
S Bonaglia1, F J A Nascimento2, M Bartoli3
1Department of Geological Sciences, Stockholm University, 106 91 Stockholm, Sweden.
Nature Communications
|October 17, 2014
Summary
Meiofauna bioturbation significantly enhances denitrification in aquatic ecosystems. However, interactions with macrofauna can alter nitrogen cycling, impacting methane production.
Area of Science:
- Ecology
- Environmental Science
- Microbiology
Background:
- Denitrification is crucial for mitigating nitrogen pollution in eutrophic aquatic environments.
- The role of meiofauna (invertebrates <1 mm) in benthic denitrification and element cycling remains poorly understood.
- Bioturbation by small invertebrates can influence microbial processes in sediments.
Purpose of the Study:
- To quantify the impact of meiofauna abundance and diversity on denitrification, carbon mineralization, and methane fluxes.
- To investigate how the presence of macrofauna modifies these meiofauna-driven processes.
- To elucidate the ecological interactions regulating nitrogen cycling in soft sediments.
Main Methods:
- Experimental manipulation of meiofauna and macrofauna populations in benthic systems.
- Measurement of denitrification rates, carbon mineralization, and methane efflux.
- Analysis of the influence of faunal abundance and diversity on microbial processes.
Main Results:
- Sediments with abundant and diverse meiofauna showed doubled denitrification rates compared to those with low meiofauna.
- Meiofauna bioturbation stimulates nitrifying and denitrifying bacteria.
- High meiofauna densities with bivalves did not enhance denitrification but increased dissimilatory nitrate reduction to ammonium and methane efflux.
Conclusions:
- Meiofauna play a significant role in stimulating denitrification through bioturbation in benthic ecosystems.
- Ecological interactions between meiofauna, macrofauna, and bacteria are critical regulators of nitrogen cycling.
- Understanding these complex interactions is essential for managing eutrophication and its consequences.
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