Carbon, nitrogen and their isotope composition of eelgrass from Virginia Coastal Lagoons and turtlegrass from St George Sound FL

Website: https://www.bco-dmo.org/dataset/746307
Data Type: Other Field Results
Version: 1
Version Date: 2018-10-10

Project
» Toward an Improved Understanding of Blue Carbon: The Role of Seagrasses in Sequestering CO2 (Seagrass Blue Carbon)
ContributorsAffiliationRole
Zimmerman, Richard C.Old Dominion University (ODU)Principal Investigator
Burdige, David J.Old Dominion University (ODU)Co-Principal Investigator
Copley, NancyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Abstract
This dataset includes results of carbon and nitrogen analyses on seagrasses collected in the Virginia Coastal Lagoons and from St. George Sound FL in May, 2017.


Coverage

Spatial Extent: N:37.343211 E:-75.732307 S:29.853211 W:-84.551509
Temporal Extent: 2017-05 - 2017-07

Dataset Description

This dataset includes results of carbon and nitrogen analyses on seagrasses collected in the Virginia Coastal Lagoons and from St. George Sound FL.


Methods & Sampling

Seagrass samples were collected randomly from each site by hand using 6" diameter PVC cores pounded into the sediment. Intact plants, including roots and rhizomes, were separated from the sediment and organic debris. The green shoots were separated from roots & rhizomes, rinsed in fresh water and dried separately at -60° C. Dried samples were ground in a mortar and pestle using liquid nitrogen and re-dried. The dry powder was analyzed for percent Carbon, percent Nitrogen, delta-13C, and delta-15N by the Stable Isotope Facility, U.C. Davis.

Samples were collected by hand, using hand tools.  Chemical and isotope analyses were performed by the Stable Isotope Facility, UC Davis using a PDZ Europa ANCA-GSL elemental analyzer interfaced to a PDZ Europa 20-20 isotope ratio mass spectrometer (Sercon Ltd., Cheshire, UK).

Data were segregated by location, tissue type, and species.  Means and errors were calculated from 10 to 90 replicate samples (separate plants).


Data Processing Description

BCO-DMO Processing Notes:
- added conventional header with dataset name, PI name, version date
- modified parameter names to conform with BCO-DMO naming conventions
- added columns for site, lat, and lon


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Data Files

File
seagrass_CN.csv
(Comma Separated Values (.csv), 61.58 KB)
MD5:a3639cf38133405082c71df33f74f582
Primary data file for dataset ID 746307

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Parameters

ParameterDescriptionUnits
Location

Location of sample collection

unitless
lat

latitude; north is positive

decimal degrees
lon

longitude; east is postive

decimal degrees
Sample_ID

sample identifier

unitless
d13C

the ratio of stable isotopes 13C:12C

unitless
C_Amount_ug

mass of Carbon in the sample

micrograms
d13C_Comment

comments pertaining to delta 13C analysis

unitless
d15N

the ratio of stable isotopes 15N:14N

unitless
N_Amount_ug

mass of Nitrogen in the sample

micrograms
Dry_Mass_mg

dry mass of sample

milligrams
pcnt_C_g_per_gDW

percent Carbon in sample dry weight

unitless (grams/grams)
pcnt_N_g_per_gDW

percent Nitrogen in sample dry weight

unitless (grams/grams)
C_to_N

Carbon to Nitrogen ratio

unitless (mol/mol)
d15N_Comment

comments pertaining to delta 15N analysis

unitless
Tray_Name

sample tray identifier

unitless
Well_Id

well identifier

unitless
Type_of_Material

type of plant material; leaf or root/rhyzome

unitless
Analysis

type of analyses performed on sample

unitless
OurLabID

intermal sample identifier assigned by researcher's laborator

unitless
Analysis_Number

sample identifier assigned by Stable Isotope Facility

unitless


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Instruments

Dataset-specific Instrument Name
PDZ Europa ANCA-GSL elemental analyzer
Generic Instrument Name
Elemental Analyzer
Dataset-specific Description
Used for chemical and isotope analyses.
Generic Instrument Description
Instruments that quantify carbon, nitrogen and sometimes other elements by combusting the sample at very high temperature and assaying the resulting gaseous oxides. Usually used for samples including organic material.

Dataset-specific Instrument Name
PDZ Europa 20-20 isotope ratio mass spectrometer (Sercon Ltd., Cheshire, UK)
Generic Instrument Name
Isotope-ratio Mass Spectrometer
Dataset-specific Description
Used for chemical and isotope analyses.
Generic Instrument Description
The Isotope-ratio Mass Spectrometer is a particular type of mass spectrometer used to measure the relative abundance of isotopes in a given sample (e.g. VG Prism II Isotope Ratio Mass-Spectrometer).


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Project Information

Toward an Improved Understanding of Blue Carbon: The Role of Seagrasses in Sequestering CO2 (Seagrass Blue Carbon)

Coverage: Chesapeake Bay, Northern Gulf of Mexico, and Bahamas Banks


NSF abstract:

This research will develop a quantitative understanding of the factors controlling carbon cycling in seagrass meadows that will improve our ability to quantify their potential as blue carbon sinks and predict their future response to climate change, including sea level rise, ocean warming and ocean acidification. This project will advance a new generation of bio-optical-geochemical models and tools (ECHOES) that have the potential to be transform our ability to measure and predict carbon dynamics in shallow water systems.

This study will utilize cutting-edge methods for evaluating oxygen and carbon exchange (Eulerian and eddy covariance techniques) combined with biomass, sedimentary, and water column measurements to develop and test numerical models that can be scaled up to quantify the dynamics of carbon cycling and sequestration in seagrass meadows in temperate and tropical environments of the West Atlantic continental margin that encompass both siliciclastic and carbonate sediments. The comparative analysis across latitudinal and geochemical gradients will address the relative contributions of different species and geochemical processes to better constrain the role of seagrass carbon sequestration to global biogeochemical cycles. Specifically the research will quantify: (i) the relationship between C stocks and standing biomass for different species with different life histories and structural complexity, (ii) the influence of above- and below-ground metabolism on carbon exchange, and (iii) the influence of sediment type (siliciclastic vs. carbonate) on Blue Carbon storage. Seagrass biomass, growth rates, carbon content and isotope composition (above- and below-ground), organic carbon deposition and export will be measured. Sedimentation rates and isotopic composition of PIC, POC, and iron sulfide precipitates, as well as porewater concentrations of dissolved sulfide, CO2, alkalinity and salinity will be determined in order to develop a bio-optical-geochemical model that will predict the impact of seagrass metabolism on sediment geochemical processes that control carbon cycling in shallow waters. Model predictions will be validated against direct measurements of DIC and O2 exchange in seagrass meadows, enabling us to scale-up the density-dependent processes to predict the impacts of seagrass distribution and density on carbon cycling and sequestration across the submarine landscape.

Status, as of 09 June 2016: This project has been recommended for funding by NSF's Division of Ocean Sciences.



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Funding

Funding SourceAward
NSF Division of Ocean Sciences (NSF OCE)
NSF Division of Ocean Sciences (NSF OCE)

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