Dataset: seal_and_prey_stable_isotopes
Deployment: Stable_Isotope_Core_seals

Isotope ratios of carbon and nitrogen from harbor seals and prey species.

Lead Principal Investigator:

Alejandro Acevedo-Gutierrez (Western Washington University, WWU)

Co-Principal Investigator:

Jeffrey F Bromaghin (United States Geological Survey, USGS)

Steven J Jeffries (Washington Department of Fish and Wildlife)

John M Kennish (University of Alaska, Anchorage, UAA)

Monique M Lance (Washington Department of Fish and Wildlife)

Philip S. Levin (National Marine Fisheries Service, NMFS)

BCO-DMO Data Manager:

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

Project:

Responses of Seals and Sea Lions to Increased Rockfish Density (Seal_response_to_prey)

Current State:

Final no updates expected

Version:

06 Dec 2012

Version Date:

2012-12-06

Data URL:

https://www.bco-dmo.org/dataset-deployment/455580/data

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Description

In April and June 2009, tissues from harbor seals and their prey (fish species) were analyzed at the Stable Isotope Core Laboratory at Washington State University. Reported results include: %C, %N, delta 13C relative to VPDB, and delta 15N relative to air.

Methods & Sampling

Dataset acquisition description

Further methodology is available in thein the lab report (PDF).

Samples for isotopic analysis were converted to N2 and CO2 with an elemental analyzer (Costech Analytical ECS 4010). The two gases were separated with a 3m GC column and analyzed with a continuous flow isotope ratio mass spectrometer (Thermo Finnigan Delta PlusXP).

The 2-sigma uncertainty of both carbon and nitrogen isotopic results is 0.5 per mill, unless otherwise indicated.

Instrument stability checks and necessary calibrations were performed prior to all analyses. A linearity check prior to analysis of these samples indicated 13C linearity of 0.045 per mil/V and 15N linearity of 0.04 per mil per volt. These are within the 0.06 per mil/V spec defined by the manufacturer. Blind reference materials (in this case, two replicates of protein standard B-2155) were also analyzed with the samples as a check of normalization.

Delta 13C and 15N values were calculated using a two point normalization by fitting a regression line through two running standards. %C and %N were calculated with a multi-point normalization using acetanilide. See the following:
Normalization information for April 2009 samples (PDF)
Normalization information for June 2009 samples (PDF)

Data Processing Description

Dataset Processing Description

Parameter names were modified to conform with BCO-DMO conventions. Data from 2 Excel files (1 for each processing date) were merged into 1 dataset.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0550443	NSF Division of Ocean Sciences

Instruments

CHN Elemental Analyzer

Supplied Description:

Samples were converted to N2 and CO2 with a Costech Analytical ECS 4010 elemental analyzer.

Instrument Type

Generic Name: CHN Elemental Analyzer

Acronym: CHN_EA

Generic Description:

A CHN Elemental Analyzer is used for the determination of carbon, hydrogen, and nitrogen content in organic and other types of materials, including solids, liquids, volatile, and viscous samples.

Isotope-ratio Mass Spectrometer

Supplied Description:

Samples were analyzed with a Thermo Finnigan Delta PlusXP continuous flow isotope ratio mass spectrometer.

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).

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
common_name	Common name of the species from which the sample was taken.	text	common_name
lab_id	Sample ID number assigned by the lab.	unitless	sample
sample_id	Sample ID number.	unitless	sample
d13C_VPDB	delta 13C relative to VPDB x 1000; the stable isotope ratio of 13C.	per mil	no_bcodmo_term
pcnt_C	Percent Carbon.	%	no_bcodmo_term
d15N_air	delta 15N relative to air x 1000; the stable isotope ratio of 15N.	per mil	no_bcodmo_term
pcnt_N	Percent Nitrogen.	%	no_bcodmo_term
date_lab	Date of results reported by the lab.	mm/dd/YYYY	date

Database

Contribute Data

Dataset: seal_and_prey_stable_isotopes
Deployment: Stable_Isotope_Core_seals

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: seal_and_prey_stable_isotopesDeployment: Stable_Isotope_Core_seals

Dataset acquisition description

Dataset Processing Description

Dataset: seal_and_prey_stable_isotopes
Deployment: Stable_Isotope_Core_seals