Ecological control of nitrite in the upper ocean

Journal Article
Ecological control of nitrite in the upper ocean
Zakem, E., A. Al-Haj, M. Church, G. van Dijken, S. Dutkiewicz, S. Foster, R. Fulweiler, M. Mills and M.J. Follows (2018)
Nature Communications, 9: 1206 (doi:10.1038/s41467-018-03553-w)

Abstract/Summary:

Microorganisms oxidize organic nitrogen to nitrate in a series of steps. Nitrite, an intermediate product, accumulates at the base of the sunlit layer in the subtropical ocean, forming a primary nitrite maximum, but can accumulate throughout the sunlit layer at higher latitudes. We model nitrifying chemoautotrophs in a marine ecosystem and demonstrate that microbial community interactions can explain the nitrite distributions. Our theoretical framework proposes that nitrite can accumulate to a higher concentration than ammonium because of differences in underlying redox chemistry and cell size between ammonia- and nitrite-oxidizing chemoautotrophs. Using ocean circulation models, we demonstrate that nitrifying microorganisms are excluded in the sunlit layer when phytoplankton are nitrogen-limited, but thrive at depth when phytoplankton become light-limited, resulting in nitrite accumulation there. However, nitrifying microorganisms may coexist in the sunlit layer when phytoplankton are iron- or light-limited (often in higher latitudes). These results improve understanding of the controls on nitrification, and provide a framework for representing chemoautotrophs and their biogeochemical effects in ocean models.

Citation:

Zakem, E., A. Al-Haj, M. Church, G. van Dijken, S. Dutkiewicz, S. Foster, R. Fulweiler, M. Mills and M.J. Follows (2018): Ecological control of nitrite in the upper ocean. Nature Communications, 9: 1206 (doi:10.1038/s41467-018-03553-w) (http://doi.org/10.1038/s41467-018-03553-w)
  • Journal Article
Ecological control of nitrite in the upper ocean

Zakem, E., A. Al-Haj, M. Church, G. van Dijken, S. Dutkiewicz, S. Foster, R. Fulweiler, M. Mills and M.J. Follows

9: 1206 (doi:10.1038/s41467-018-03553-w)
2018

Abstract/Summary: 

Microorganisms oxidize organic nitrogen to nitrate in a series of steps. Nitrite, an intermediate product, accumulates at the base of the sunlit layer in the subtropical ocean, forming a primary nitrite maximum, but can accumulate throughout the sunlit layer at higher latitudes. We model nitrifying chemoautotrophs in a marine ecosystem and demonstrate that microbial community interactions can explain the nitrite distributions. Our theoretical framework proposes that nitrite can accumulate to a higher concentration than ammonium because of differences in underlying redox chemistry and cell size between ammonia- and nitrite-oxidizing chemoautotrophs. Using ocean circulation models, we demonstrate that nitrifying microorganisms are excluded in the sunlit layer when phytoplankton are nitrogen-limited, but thrive at depth when phytoplankton become light-limited, resulting in nitrite accumulation there. However, nitrifying microorganisms may coexist in the sunlit layer when phytoplankton are iron- or light-limited (often in higher latitudes). These results improve understanding of the controls on nitrification, and provide a framework for representing chemoautotrophs and their biogeochemical effects in ocean models.

Posted to public: 

Friday, July 20, 2018 - 17:48