Dataset: Southern Ocean zooplankton N isotopes
Deployment: VOY019

Size-fractionated zooplankton δ15N from net tows in the African sector

Principal Investigator:

Contact:

Sandi M. Smart (Stellenbosch University)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

High-resolution, Assemblage-specific Records of Diatom-bound N Isotopes from the Indian Sector of the Antarctic Ocean (Diatom-bound_N_Isotopes)

MRI: Acquisition of Stable Isotope Instrumentation for the Biogeosciences at Princeton University (stable isotope instrumentation)

Understanding the nitrogen isotopes of planktonic foraminifera: A modern Sargasso Sea study (N Isotopes Foraminifera)

Current State:

Final no updates expected

Data URL:

https://www.bco-dmo.org/dataset-deployment/805819/data

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Description

This dataset contains N isotope measurements of the different size-fractions of zooplankton collected by net tows.

Methods & Sampling

Dataset acquisition description

Zooplankton were collected by towing a 200-μm-mesh plankton net for 90 min at a target depth within the mixed layer. Tow material was then sieved into the following size fractions: <150, 150-250, 250-500, 500-1000, 1000-2000, 2000-5000 and >5000 µm. Each size-fraction was then filtered down onto a pre-combusted 0.7-μm-pore-size GF/F and frozen at −20°C for elemental and isotopic analysis.

The N isotope composition of size-fractionated zooplankton samples were measured at the University of Cape Town using a Thermo Scientific FLASH 2000 elemental analyzer coupled to a Thermo Scientific Delta V Plus mass spectrometer.

See methods section of Smart et al. (2020) for more detail.

Data Processing Description

Dataset Processing Description

N isotope measurements were referenced to atmospheric N₂ using three in-house organic standards: Choc, Merck Gel and Valine. Samples that contained GF/F material were additionally corrected for the contribution of the N blank associated with the filter paper.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0922345	NSF Division of Ocean Sciences
OCE-1060947	NSF Division of Ocean Sciences
PLR-1401489	NSF Division of Polar Programs

Instruments

Elemental Analyzer

Supplied Name: Thermo Scientific FLASH 2000 elemental analyzer

Supplied Description:

Instrument Type

Generic Name: Elemental Analyzer

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB01/

Generic 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.

Isotope-ratio Mass Spectrometer

Supplied Name: Thermo Scientific Delta V Plus

Supplied Description:

Instrument Type

Generic Name: Isotope-ratio Mass Spectrometer

Acronym: IR Mass Spec; IRMS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic 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).

Isotope-ratio Mass Spectrometer

Supplied Name: Thermo Scientific Delta V Plus

Supplied Description:

Instrument Type

Generic Name: Isotope-ratio Mass Spectrometer

Acronym: IR Mass Spec; IRMS

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/LAB16/

Generic 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).

Plankton Net

Supplied Name: 200-um-mesh plankton net

Supplied Description:

Instrument Type

Generic Name: Plankton Net

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/22/

Generic Description:

A Plankton Net is a generic term for a sampling net that is used to collect plankton. It is used only when detailed instrument documentation is not available.

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
cruise	Cruise identifier	unitless	cruise_id
ship	Ship name	unitless	ship
tow	Tow number	unitless	tow
date	Date; format: yyyy-mm-dd	unitless	date
time_starttow	Time at start of tow (UTC); format: HH:MM	unitless	time
time_endtow	Time at end of tow (UTC); format: HH:MM	unitless	time
size_fraction	Sample size fraction. Tow material was sieved into the following size fractions: <150, 150-250, 250-500, 500-1000, 1000-2000, 2000-5000 and >5000 um.	micrometers (um)	net_mesh
notes	Indicates if a particular organism was measured (e.g., copepod) or not (in which case the sample is labelled ‘bulk’)	unitless	comment
latitude	Latitude; positive values = North	decimal degrees	lat
longitude	Longitude; positive values = East	decimal degrees	lon
depth_tow	Depth of the tow	meters (m)	depth
d15Nzoop_avg	Average d15N. d15N is the nitrogen isotopic composition of a sample expressed in delta notation (d15N in units of per mil, ‰) relative to atmospheric N2, where d15N = {[(15N/14N)sample/(15N/14N)atmN2] – 1} × 1000	per mil vs AIR	d15N_bio
d15Nzoop_sd	Standard deviation of d15Nzoop_avg	per mil vs AIR	d15N_bio
d15Nzoop_n	Number of replicate measurements of d15Nzoop_avg	unitless	num_reps
ISO_DateTime_UTC_starttow	Date and time (UTC) of start of tow formatted to ISO 8601 standard; format: yyyy-mm-ddTHH:MM:SSZ	unitless	ISO_DateTime_UTC
ISO_DateTime_UTC_endtow	Date and time (UTC) of end of tow formatted to ISO 8601 standard; format: yyyy-mm-ddTHH:MM:SSZ	unitless	ISO_DateTime_UTC

Database

Contribute Data

Dataset: Southern Ocean zooplankton N isotopes
Deployment: VOY019

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: Southern Ocean zooplankton N isotopesDeployment: VOY019

Dataset acquisition description

Dataset Processing Description

Dataset: Southern Ocean zooplankton N isotopes
Deployment: VOY019