Nitrogen isotopes of coral skeleton-bound organic matter from various sampling locations world-wide

Website: https://www.bco-dmo.org/dataset/683097
Data Type: Other Field Results
Version: 2
Version Date: 2018-09-13

Project
» Collaborative Research: Identifying the Role of Basin-scale Climate Variability in the Decline of Atlantic Corals (Coral climate effects)
ContributorsAffiliationRole
Sigman, Daniel M.Princeton UniversityPrincipal Investigator
Cohen, Anne L.Woods Hole Oceanographic Institution (WHOI)Co-Principal Investigator
de Putron, Samantha J.Bermuda Institute of Ocean Sciences (BIOS)Co-Principal Investigator
Wang, Xingchen TonyCalifornia Institute of Technology (Caltech)Contact
York, Amber D.Woods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager

Abstract
This dataset contains the average CS-d15N (nitrogen isotopes of coral skeleton-bound organic matter) values for three sampling locations. Sampling occurred in the Oman margin in 1996, Kiritimati (Christmas Island) in 1998, and Bermuda in 2014.


Coverage

Spatial Extent: N:32.45811 E:157.4 S:1.87 W:-64.83445
Temporal Extent: 1996 - 2014

Dataset Description

These data were published in Wang et al., 2016 and Wang et al., 2018.

The following table is a statistical summary of results:
Table1, Wang et al., 2016 (pdf)


Methods & Sampling

The “age” for these corals were determined by either counting growth rings on X-ray images of the coral skeleton or matching with other parameters (Sr/Ca or oxygen isotopes) in the same coral skeleton.

At each site, the core-averaged skeletal d15N was first calculated by averaging all available d15N data in each coral core. Then the site-averaged skeletal d15N was calculated by averaging the core-averaged skeletal d15N of all coral cores from the same site.

Samples from Bermuda were collected from a single brain coral (of the species Diploria labyrinthiformis) at Hog Reef, Bermuda (32.45811, -64.83445) in July of 2014 at a depth of 3m.

For more details, see Wang et al., 2016.


Data Processing Description

BCO-DMO processing notes:
* added a conventional header with dataset name, PI name, version date
* modified parameter names to conform with BCO-DMO naming conventions
* blank values replaced with no data value 'nd'
* Changed site name "Christmas Island" to "Kiritimati Island" to be consistent with publication referenced.
* added sampling depth, sampling year, approximate latitude and longitude site locations that were included in a statistical summary table.
* rounded fractional calendar year to three decimal places in Oman data
* dataset v1: 2017-02-27 replaced by dataset version v2: 2018-09-14. Data from Bermuda added to the dataset.


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Data Files

File
N_coral_toplevel.csv
(Comma Separated Values (.csv), 9.62 KB)
MD5:86142702252864b9514c1d56ad10f64c
Primary data file for dataset ID 683097

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Related Publications

Wang, X. T., A. L. Cohen, V. Luu, H. Ren, Z. Su, G. H. Haug, D. M. Sigman (2018), Natural forcing of the North Atlantic nitrogen cycle in the Anthropocene. Proceedings of the National Academy of Sciences. doi:10.1073/pnas.1801049115.
Results
Wang, X. T., Sigman, D. M., Cohen, A. L., Sinclair, D. J., Sherrell, R. M., Cobb, K. M., … Ren, H. (2016). Influence of open ocean nitrogen supply on the skeletal δ 15 N of modern shallow-water scleractinian corals. Earth and Planetary Science Letters, 441, 125–132. doi:10.1016/j.epsl.2016.02.032
Methods

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Parameters

ParameterDescriptionUnits
siteLocation of sampling unitless
collection_yearYear of collection in format yyyy unitless
lat_approxApproximate latitude of sampling site decimal degrees
lon_approxApproximate longitude of sampling site decimal degrees
site_depthDepth of sampling location meters
ageAge of coral colony sampled decimal year
depthDepth (middle interval) within sample core centimeters
CS_d15N_avgAverage Coral Skeletal d15N. d15N is the ratio of stable isotopes 15N:14N. permil (0/00) vs air
CS_d15N_1sdFirst standard deviation of Coral Skeletal d15N. d15N is the ratio of stable isotopes 15N:14N. permil (0/00) vs air


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Instruments

Dataset-specific Instrument Name
IRMS
Generic Instrument Name
Isotope-ratio Mass Spectrometer
Dataset-specific Description
Used "denitrifier method" with isotope ratio mass spectrometer (IRMS)
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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Deployments

CoralClimateProj_Kiritimati

Website
Platform
Kiritimati
Description
Sampling took place in 1998

Methods & Sampling
Sampling took place in 1998.

CoralClimateProj_Oman_margin

Website
Platform
Oman_margin
Description
Methods & Sampling
Sampled in 1996

CoralClimateProj_Bermuda

Website
Platform
shoreside Bermuda


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Project Information

Collaborative Research: Identifying the Role of Basin-scale Climate Variability in the Decline of Atlantic Corals (Coral climate effects)

Coverage: Bermuda and wider Caribbean


Text from the NSF award abstract:

Human carbon dioxide emissions are causing measureable changes in ocean conditions. Many of these changes negatively affect coral reef ecosystems, reducing their ability to provide food, arable land, tourist destinations and coastline protection for hundreds of millions of people worldwide. This project focuses on the effects of enhanced stratification, caused by ocean warming, on the growth of reef-building corals across the Caribbean and Bermuda. Enhanced stratification impacts primary productivity which generates food for corals. Initial data generated by the investigators suggest that Atlantic coral growth has declined in the last 5 decades in response to these changes. A laboratory-based experiment is designed to test this hypothesis. If verified, the projected decline in Atlantic primary productivity through the 21st century could potentially rival and will certainly exacerbate the effects of warming and ocean acidification on coral reef ecosystems across the North Atlantic. Support is provided for graduate research, and undergraduate participation is facilitated through the Woods Hole Oceanographic Institution Summer Fellowship and the Bermuda Institute of Ocean Sciences-Princeton Environmental Institute Summer Internship Programs. The results will be presented at national and international meetings and disseminated in a timely manner through peer-reviewed publications. All data produced through this program will be archived in the Biological and Chemical Oceanographic Data Management Office.

Anthropogenic climate change has emerged as a principle threat to coral reef survival in the 21st century. In addition to ocean warming and acidification, global climate models project enhanced stratification of the upper oceans through the 21st century and a consequent decline in productivity, by up to 50%, in the North Atlantic. This project employs controlled laboratory manipulation experiments to test the link between productivity and growth of the dominant reef-building corals across the Caribbean and Bermuda. Preliminary data generated by the investigators, including multi-decade long coral growth histories and nitrogen isotope ratios of coral tissue and skeleton, suggest that coral growth across the region has declined over the past 50 years in response to productivity changes already underway. If the link between ocean circulation, productivity decline, and coral growth is verified, the projected 21st century decline in productivity could rival and will certainly exacerbate the effects of warming and ocean acidification on North Atlantic coral reef ecosystems.



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Funding

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

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