DOI: 10.5285/72b3cdc8-60e5-4c0d-9ebe-32dff843de07
title: Stable isotope values of fish tissues (muscle and otolith) from the Barents Sea

description: The dataset contains 3 data files. Firstly, it contains one set of stable isotope compositions expressed as delta13C, d15N, d34S values recovered from fish muscle from a variety of species captured in September 2019 across the Barents Sea as part of the joint IMR-PINRO Barents Sea Ecosystem Survey. Samples were collected by Dr Matthew Cobain and Dr Kim Vane, and isotope data analysed at the university of Southampton. A second dataset contains delta13C and delta18O compositions of fish otolith carbonate recovered from a subset of the same fish. A final sheet contains the full metadata associated with each fish sampled on the survey. All samples were processed by Dr Matthew Cobain or Prof Clive Trueman and stable isotope values determined at the University of Southampton. 

Funding: 
Project was funded under the NERC Changing Arctic Ocean project, Coldifsh (NE/R012520/1).
description: All fish were collected during the 2019 IMR-PINRO Barents Sea Ecosystem Survey. Cruise report containing full details of cruise stations, together with full details of environmental conditions and ecosystem context is linked in the Related URL section.
On board ship, fish were weighed and length measured. 1 cm^3 section of while muscle was excised from the dorsal musculature above the lateral line, wrapped in pre-labelled tin foil and immediately frozen at -20 degrees. In the case of small fish, whole fish were frozen and sub-sampled in the laboratory. Jellyfish bell tissue was excised on board or whole jellyfish bells frozen and subsampled in the laboratory.

Otoliths were removed from a sub-sample of fishes onboard ship, manually cleaned and placed in cell culture trays.

Muscle tissues were not lipid extracted prior to analyses. Frozen muscle was freeze dried, crushed in an agate pestle and mortar and approximately 0.3-1mg of muscle powder accurately weighed into tin boats prior to introduction to the mass spectrometer.

Otoliths were cleaned (if necessary) by wetting and manually removing any adhering tissue.

Otoliths were mounted whole onto glass slides, sulcus side upwards and approximately 50 micrograms of powder was excised from the sulcal ridge using a Dremel hand engraving tool with a cylindrical diamond-tipped drill bit. Powders were transferred to borosilicate vials prior to analysis. Approximately 0.3-0.5 micrograms of powder was accurately weighed into analysis vials for introduction to the mass spectrometer.

Maturity was assessed by IMR Norway and is included in this dataset where known.
description: CNS isotope values were determined using an Elementar visIon Isotope ratio mass spectrometer coupled to an EA elemental analyser.

Otolith CO isotope data was determined on a Thermo Finnegan MAT253 mass spectrometer coupled to a Kiel carbonate device.
description: Isotope mass spectrometers were calibrated against international reference standards, and accuracy and precision monitored through replicated analyses of internal standard materials (homogenised cod muscle for CNS data and powdered homogenised otolith for otolith d13C, d18O values.

Long term precision assessed as standard deviation of replicate analyses of internal standards (as unknown samples) was 0.15per-mille for d15N, 0.08per-mille for d13C and 0.5per-mille for d34S, and &lt;0.1per-mille for both d13C and d18O values of otolith carbonate.