A review of how we assess denitrification in oyster habitats and proposed guidelines for future studies

Ray, Nicholas E.; Hancock, Boze; Brush, Mark J.; Colden, Allison; Cornwell, Jeffrey C.; Labrie, Micheline S.; Maguire, Timothy J.; Maxwell, T. R. A.; Rogers, Daniel R.; Stevick, Rebecca J.; Kellogg, M. Lisa; Smyth, Ashley R.; Fulweiler, Robinson W.

doi:10.1002/lom3.10456

Cited by 20 publications

(9 citation statements)

References 106 publications

(178 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We performed an on‐board incubation experiment with sediments from 16 stations of the ISSS‐2020 expedition (Figure 1) to quantify net sediment‐water N 2 O fluxes. The approach uses intact multicores to minimize disturbance of the sediment‐water interface, and is commonly used in other systems to measure sediment‐water fluxes (see e.g., Ray et al., 2021 for general considerations). Sediment cores were taken with an Oktopus multicorer with ca.…”

Section: Methodsmentioning

confidence: 99%

Nitrous Oxide Dynamics in the Siberian Arctic Ocean and Vulnerability to Climate Change

et al. 2023

Self Cite

View full text Add to dashboard Cite

Nitrous oxide (N2O) is a strong greenhouse gas and stratospheric ozone‐depleting substance. Around 20% of global emissions stem from the ocean, but current estimates and future projections are uncertain due to poor spatial coverage over large areas and limited understanding of drivers of N2O dynamics. Here, we focus on the extensive and particularly data‐lean Arctic Ocean shelves north of Siberia that experience rapid warming and increasing input of land‐derived nitrogen with permafrost thaw. We combine water column N2O measurements from two expeditions with on‐board incubation of intact sediment cores to assess N2O dynamics and the impact of land‐derived nitrogen. Elevated nitrogen concentrations in water column and sediments were observed near large river mouths. Concentrations of N2O were only weakly correlated with dissolved nitrogen and turbidity, reflecting particulate matter from rivers and coastal erosion, and correlations varied between river plumes. Surface water N2O concentrations were on average close to equilibrium with the atmosphere, but varied widely (N2O saturation 38%–180%), indicating strong local N2O sources and sinks. Water column N2O profiles and low sediment‐water N2O fluxes do not support strong sedimentary sources or sinks. We suggest that N2O dynamics in the region are influenced by water column N2O consumption under aerobic conditions or in anoxic microsites of particles, and possibly also by water column N2O production. Changes in biogeochemical and physical conditions will likely alter N2O dynamics in the Siberian Arctic Ocean over the coming decades, in addition to reduced N2O solubility in a warmer ocean.

show abstract

Section: Methodsmentioning

confidence: 99%

Nitrous Oxide Dynamics in the Siberian Arctic Ocean and Vulnerability to Climate Change

et al. 2023

Self Cite

View full text Add to dashboard Cite

show abstract

“…Implementing oyster-mediated denitrification as a mitigation tool will require additional measurements of denitrification rates from oyster habitat and non-oyster habitat for comparison. Recently, an effort was undertaken to develop recommendations for managers on how best to measure denitrification and what environmental characteristics should simultaneously be collected to help inform future management goals . Some of these recommendations include directly measuring denitrification with the N 2 /Ar technique (determines the net N 2 production as the difference between N 2 production by denitrification and N 2 consumption by N 2 fixation), collecting rate measurements seasonally, and reporting environmental parameters such as sediment oxygen demand and inorganic nutrient concentrations (i.e., ammonium and nitrate concentrations) .…”

Section: Oysters and Denitrificationmentioning

confidence: 99%

“…Recently, an effort was undertaken to develop recommendations for managers on how best to measure denitrification and what environmental characteristics should simultaneously be collected to help inform future management goals. 52 Some of these recommendations include directly measuring denitrification with the N 2 /Ar technique (determines the net N 2 production as the difference between N 2 production by denitrification and N 2 consumption by N 2 fixation), collecting rate measurements seasonally, and reporting environmental parameters such as sediment oxygen demand and inorganic nutrient concentrations (i.e., ammonium and nitrate concentrations). 52 Additionally, there are efforts that are developing enhanced denitrification estimates using data where the sediments and the whole reef community are included in the N 2 −N flux measurements to determine the total N reduction from denitrification per reef acre.…”

Section: ■ Oysters and Denitrificationmentioning

confidence: 99%

“…52 Some of these recommendations include directly measuring denitrification with the N 2 /Ar technique (determines the net N 2 production as the difference between N 2 production by denitrification and N 2 consumption by N 2 fixation), collecting rate measurements seasonally, and reporting environmental parameters such as sediment oxygen demand and inorganic nutrient concentrations (i.e., ammonium and nitrate concentrations). 52 Additionally, there are efforts that are developing enhanced denitrification estimates using data where the sediments and the whole reef community are included in the N 2 −N flux measurements to determine the total N reduction from denitrification per reef acre. 53 ■ IMPLEMENTING OYSTER DENITRIFICATION INTO NITROGEN MANAGEMENT Many coastal areas in the United States, Asia, Australia, and Europe are required to improve water quality using nutrient reduction targets for point (e.g., wastewater) and nonpoint (e.g., stormwater runoff, agricultural runoff) sources.…”

Section: ■ Oysters and Denitrificationmentioning

confidence: 99%

See 1 more Smart Citation

Beyond Bioextraction: The Role of Oyster-Mediated Denitrification in Nutrient Management

Ayvazian

Mulvaney

Zarnoch

et al. 2021

Environ. Sci. Technol.

Self Cite

View full text Add to dashboard Cite

Recently, interest has grown in using oyster-mediated denitrification resulting from aquaculture and restoration as mechanisms for reactive nitrogen (N) removal. To date, short-term N removal through bioextraction has received the most management interest, but there is a growing body of research that has shown oysters can also mediate the long-term removal of N through denitrification (the microbial conversion of reactive N to relatively inert dinitrogen (N 2 ) gas). Oyster suspension feeding and ammonium release via waste and deposition of organic matter to the sediments can stimulate nitrification−denitrification near oyster reefs and aquaculture sites. Oysters also harbor a diverse microbial community in their tissue and shell promoting denitrification and thus enhanced N removal. Additionally, surface areas on oyster reefs provide a habitat for other filter-feeding macrofaunal communities that can further enhance denitrification. Denitrification is a complex biogeochemical process that can be difficult to convey to stakeholders. These complexities have limited consideration and inclusion of oyster-mediated denitrification within nutrient management. Although oyster-mediated denitrification will not be a standalone solution to excess N loading, it may provide an additional management tool that can leverage oyster aquaculture and habitat restoration as a N mitigation strategy. Here, we provide an overview of the biogeochemical processes involved in oyster-mediated denitrification and summarize how it could be incorporated into nutrient management efforts by various stakeholders.

show abstract

“…Underlying these changes and individual processes are various microbial guilds that may change in abundance or activity in response to the presence of oysters. For example, oyster farms are considered ‘hot spots’ for N removal via microbial denitrification (13, 14), the microbial conversion of biologically active nitrogen to unreactive di-nitrogen gas. Microbial denitrification rates are influenced by a variety of factors including the quality and quantity of organic matter (15, 16), oxygen concentrations (17), and nitrate availability (18) – all factors impacted by oyster farming (10, 19).…”

Section: Introductionmentioning

confidence: 99%

Oyster aquaculture enhances sediment microbial diversity– Insights from a multi-omics study

Stevens,

Ray,

Al-Haj

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

The global aquaculture industry has grown substantially, with consequences for coastal ecology and biogeochemistry. Oyster aquaculture can alter the availability of resources for microbes that live in sediments as oysters move large quantities of organic material to the sediments via filter feeding, possibly leading to changes in the structure and function of sediment microbial communities. Here, we use a chronosequence approach to investigate the impacts of oyster farming on sediment microbial communities over 7 years of aquaculture activity in a temperate coastal system. We detected shifts in bacterial composition (16S rRNA amplicon sequencing), changes in gene expression (meta-transcriptomics), and variations in sediment elemental concentrations (sediment geochemistry) across different durations of oyster farming. Our results indicate that both the structure and function of bacterial communities vary between control (no oysters) and farm sites, with an overall increase in diversity and a shift towards anoxic tolerance in farm sites. However, little to no variation was observed in either structure or function with respect to farming duration suggesting these sediment microbial communities are resilient to change. We also did not find any significant impact of farming on heavy metal accumulation in the sediments. The minimal influence of long-term oyster farming on sediment bacterial function and biogeochemical processes as observed here can bear important consequences for establishing best practices for sustainable farming in these areas.ImportanceSediment microbial communities drive a range of important ecosystem processes such as nutrient recycling and filtration. Oysters are well-known ecological engineers, and their presence is increasing as aquaculture expands in coastal waters globally. Determining how oyster aquaculture impacts sediment microbial processes is key to understanding current and future estuarine biogeochemical processes. Here, we use a multi-omics approach to study the effect of different durations of oyster farming on the structure and function of bacteria and elemental accumulation in the farm sediments. Our results indicate an increase in the diversity of bacterial communities in the farm sites with no such increases observed for elemental concentrations. Further, these effects persist across multiple years of farming with an increase of anoxic tolerant bacteria at farm sites. The multi-omics approach used in this study can serve as a valuable tool to facilitate understanding of the environmental impacts of oyster aquaculture.

show abstract

A review of how we assess denitrification in oyster habitats and proposed guidelines for future studies

Cited by 20 publications

References 106 publications

Nitrous Oxide Dynamics in the Siberian Arctic Ocean and Vulnerability to Climate Change

Nitrous Oxide Dynamics in the Siberian Arctic Ocean and Vulnerability to Climate Change

Beyond Bioextraction: The Role of Oyster-Mediated Denitrification in Nutrient Management

Oyster aquaculture enhances sediment microbial diversity– Insights from a multi-omics study

Contact Info

Product

Resources

About