Nitrogen and oxygen availabilities control water column nitrous oxide production during seasonal anoxia in the Chesapeake Bay

Ji, Qixing; Frey, Claudia; Sun, Xingming; Jackson, Melanie; Lee, Yea‐Shine; Jayakumar, Amal; Cornwell, Jeffrey C.; Ward, Bess B.

doi:10.5194/bg-2018-113

Cited by 4 publications

(4 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We did not look for denitrifying bacteria in our site, as denitrification is not phylogenetically conserved (Zumft 1997;Bertagnolli et al 2020) and so neither taxonomic groupings nor phylogenetic placement is likely to generate reliable information about this process. However this process is common in anoxic systems, and has been measured in the Chesapeake previously (Ji et al 2018). Furthermore, new evidence suggests that many of the taxa associated with sulfur cycling in the Chesapeake also reduce nitrate (Arora-Williams et al 2022).…”

Section: Nitrogen Cyclementioning

confidence: 91%

Microbial diversity and abundance vary along salinity, oxygen and particle size gradients in the Chesapeake Bay

Cram¹,

Hollins²,

McCarty³

et al. 2023

Preprint

View full text Add to dashboard Cite

Marine snow and other particles are abundant in estuaries, where they drive biogeochemical transformations and elemental transport. Particles range in size, thereby providing a corresponding gradient of habitats for marine microorganisms. We used quantitative amplicon sequencing, verified with microscopy, to characterize taxon-specific microbial abundances, (cells per liter of water and per mg of particles), across six particle size classes, ranging from 0.2 to 500 μm, along the main stem of the Chesapeake Bay estuary. Microbial communities varied with salinity, oxygen concentrations and particle size. Many taxonomic groups were most densely packed on large particles (in cells/mg particles), yet were primarily associated with the smallest particle size class, because small particles made up a substantially larger portion of total particle mass. However, organisms potentially involved in methanotrophy, nitrite oxidation, and sulfate reduction were found primarily on intermediately sized (5 - 180 μm) particles, where species richness was also highest. All abundant ostensibly free-living organisms, including SAR11 and Synecococcus, appeared on particles, albeit at lower abundance than in the free-living fraction, suggesting that aggregation processes may incorporate them into particles. Our approach opens a door to a more quantitative understanding of the microscale and macroscale biogeography of marine microorganisms.

show abstract

Section: Nitrogen Cyclementioning

confidence: 91%

Microbial diversity and abundance vary along salinity, oxygen and particle size gradients in the Chesapeake Bay

Cram¹,

Hollins²,

McCarty³

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

“…Below 800 m, ∆N 2 O and AOU was not linearly correlated, indicating a more complex benthic N 2 O variability. Benthic N 2 O dynamics can also be affected by organic matter remineralization, deep water mixing, and sedimentwater N 2 O exchange (Ji et al, 2018;Toyoda et al, 2021). More surveys are essential to identify the benthic N 2 O sources in the northern SCS.…”

Section: Environmental Factors For N 2 O Variabilitymentioning

confidence: 99%

Dissolved Nitrous Oxide and Hydroxylamine in the Northern South China Sea in Summer

Zhang,

Yao,

et al. 2024

JGR Biogeosciences

View full text Add to dashboard Cite

Nitrous oxide (N2O) is a potent greenhouse gas and a strong ozone‐depleting substance. Ocean is an important natural source of atmospheric N2O, which has attracted increasing attention recently as to understand the biogeochemical cycles of nitrogen in marine systems. Nitrification is one of the major N2O production pathways during which N2O is produced as a side product and hydroxylamine (NH2OH) is produced as an obligate intermediate. However, few studies have reported the NH2OH variability in natural seawater and its relationship between N2O remains ambiguous. In summer 2022, spatial distribution and influencing factors of N2O and NH2OH in the northern South China Sea (SCS) were investigated. Dissolved N2O varied from 5.79 to 34.80 nmol L−1 in water column and generally increased with water depth above 800 m. N2O was correlated with dissolved oxygen and nitrate, inferring that N2O was mainly produced via nitrification. NH2OH varied from below detection limit to 3.91 nmol L−1. The adoption of multiple standard additions can largely reduce the bias in NH2OH measurement. Structural equation modeling showed that NH2OH has a potential effect favoring excessive N2O. Surface N2O saturation ranged between 102% and 278%, indicating that the northern SCS was a net source of atmospheric N2O in summer.

show abstract

“…Researchers have used genetic observations to constrain the structure of biogeochemical models relatively successfully (Coles et al 2017;Louca et al 2016a;Preheim et al 2016;Reed et al 2014), although typically this has been done in ecosystems assumed to be at or near steadystate. In some cases, there seems to be a strong relationship between the observed genes and the function they mediate, such as with the denitrification gene nirS and nitrous oxide production in the Chesapeake Bay (Ji et al 2018). In other cases, this relationship breaks down, even for the same nirS genes (Bowen et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Major trends and environmental correlates of spatiotemporal shifts in the distribution of genes compared to a biogeochemical model simulation in the Chesapeake Bay

Preheim

Morris

Zhang

et al. 2023

Preprint

View full text Add to dashboard Cite

Microorganisms mediate critical biogeochemical transformations that affect the productivity and health of aquatic ecosystems. Metagenomic sequencing can be used to identify how the taxonomic and functional potential of microbial communities change in response to environmental variables by investigating changes in microbial genes. However, few studies directly compare gene changes to biogeochemical model predictions of corresponding processes, especially in dynamic estuarine ecosystems. We aim to understand the major drivers of spatiotemporal shifts in microbial genes and genomes within the water column of the Chesapeake and highlight the largest discrepancies of these observations with model predictions. We used a previously published shotgun metagenomic dataset from multiple months, sites, and depths within Chesapeake Bay in 2017 and a metatranscriptomic dataset from 2010-2011. We compared metagenomic observations with rates predicted with a comprehensive physical-biogeochemical model of the Bay. We found the largest changes in the relative abundance of genes involved in carbon, nitrogen, and sulfur metabolism associated with variables that change with depth and season. Several genes associated with the largest changes in gene abundance are significantly correlated to corresponding modeled processes. Yet, several discrepancies in key genes were identified, such as differences between genes mediating nitrification, higher than expected abundance and expression of denitrification genes in aerobic waters, and nitrogen fixation genes in environments with relatively high ammonia but low oxygen concentrations. This study identifies processes that align with model expectations and others that require additional investigation to determine the biogeochemical consequences of these discrepancies and their impact within an important estuarine ecosystem.

show abstract

Nitrogen and oxygen availabilities control water column nitrous oxide production during seasonal anoxia in the Chesapeake Bay

Cited by 4 publications

References 36 publications

Microbial diversity and abundance vary along salinity, oxygen and particle size gradients in the Chesapeake Bay

Microbial diversity and abundance vary along salinity, oxygen and particle size gradients in the Chesapeake Bay

Dissolved Nitrous Oxide and Hydroxylamine in the Northern South China Sea in Summer

Major trends and environmental correlates of spatiotemporal shifts in the distribution of genes compared to a biogeochemical model simulation in the Chesapeake Bay

Contact Info

Product

Resources

About