Impact of ocean acidification on benthic and water column ammonia oxidation
Article first published online: 2 NOV 2011
Copyright 2011 by the American Geophysical Union.
Geophysical Research Letters
Volume 38, Issue 21, November 2011
How to Cite
2011), Impact of ocean acidification on benthic and water column ammonia oxidation, Geophys. Res. Lett., 38, L21603, doi:10.1029/2011GL049095., , , , , , , and (
- Issue published online: 2 NOV 2011
- Article first published online: 2 NOV 2011
- Manuscript Accepted: 30 SEP 2011
- Manuscript Revised: 23 SEP 2011
- Manuscript Received: 1 AUG 2011
- ocean acidification;
 Ammonia oxidation is a key microbial process within the marine N-cycle. Sediment and water column samples from two contrasting sites in the English Channel (mud and sand) were incubated (up to 14 weeks) in CO2-acidified seawater ranging from pH 8.0 to pH 6.1. Additional observations were made off the island of Ischia (Mediterranean Sea), a natural analogue site, where long-term thermogenic CO2 ebullition occurs (from pH 8.2 to pH 7.6). Water column ammonia oxidation rates in English Channel samples decreased under low pH with near-complete inhibition at pH 6.5. Water column Ischia samples showed a similar though not statistically significant trend. However, sediment ammonia oxidation rates at all three locations were not affected by reduced pH. These observations may be explained by buffering within sediments or low-pH adaptation of the microbial ammonia oxidizing communities. Our observations have implications for modeling the future impact of ocean acidification on marine ecosystems.