Atlantic cod individual spatial behaviour and stable isotope associations in a no-take marine reserve
Cite this dataset
Monk, Christopher et al. (2023). Atlantic cod individual spatial behaviour and stable isotope associations in a no-take marine reserve [Dataset]. Dryad. https://doi.org/10.5061/dryad.pk0p2ngv6
Abstract
- Foraging is a behavioural process and, therefore, individual behaviour and diet are theorized to covary. However, few comparisons of individual behaviour type and diet exist in the wild.
- We tested whether behaviour type and diet covary in a protected population of Atlantic cod, Gadus morhua.
- Working in a no-take marine reserve, we could collect data on natural behavioural variation and diet choice with minimal anthropogenic disturbance. We inferred behaviour using acoustic telemetry and diet from stable isotope compositions (expressed as δ13C and δ15N values). We further investigated whether behaviour and diet could have survival costs.
- We found cod with shorter diel vertical migration distances fed at higher trophic levels. Cod δ13C and δ15N values scaled positively with body size. Neither behaviour nor diet predicted survival, indicating phenotypic diversity is maintained without survival costs for cod in a protected ecosystem.
- The links between diet and diel vertical migration highlight that future work is needed to understand whether the shifts in this behaviour during environmental change (e.g. fishing or climate), could lead to trophic cascades.
README: Atlantic cod individual spatial behaviour and stable isotope associations in a no-take marine reserve
https://doi.org/10.5061/dryad.pk0p2ngv6
This dataset contains all data used in the analysis for the associated manuscript, as well as an R script which can be used to replicate the analysis. There are six files, including multispecies stable isotope data, cod sampling data, cod specific stable isotope data, cod meta data, cod positions and an R script for analysis.
Description of the data and file structure
file: cod_stable_isotopes.rdata
description: Cod specific stable isotopes data in the .rdata format
columns:
TRIP - sampling event
Lcm - Fork length (in cm) of the cod measured during sampling
d13C - δ13C values in ‰
d15N - δ15N values in ‰
X.C - %C
X.N - %N
C.N.Ratio - C:N ratio
serial - transmitter ID of the cod (connected to positioning dataset)
samplingDate - date of sampling
x - UTM x (m) location of cod capture
y - UTM y (m) location of cod capture
month - month the sampling event took place
year - year the sampling event took place
quarter - quarter of the year the sampling event took place
file: TVE2011Effort.csv
description: Sampling effort and locations in the Tvedestrand fjord
columns:
Trip: The sampling event
Pos: The specific sampling location, encoded numerically
Lat: The latitude of the sampling site in decimal degrees
Lon: The longitude of the sampling site in decimal degrees
Gear: The sampling gear used
file: SI.rdata
description: stable isotope samples collected throughout the Tvedestrand foodweb.
columns:
Trip: The sampling event corresponding to the Effort.Rdata encoding
Pos: The sampling location corresponding to the Effort.Rdata encoding
Species: The binomial name of the sampled organism
Lcm: The length of the sampled organism when measured
MuBiop: Unique biopsy ID
MB.Number: Secondary biopsy ID
SIA.ID: Unique stable isotope sample ID
SIA.Num: secondard stable isotope ID
d13C: The delta 13C stable isotope value in ‰
d15N: The delta 15N stable isotope value in ‰
X.C: %C
X.N: %N
C.N.Ratio: C:N ratio
Comment: Notes related to the sample
file: telem.rdata
description: Data collected during each cod sampling event, including recaptures
columns:
scientific_name - species sampled
ReleaseDate - date sampled
tag_expected_life_time_days - expected battery life of the acoustic transmitter in days
MinDelaySec - minimum burst interval of the acoustic transmitter in seconds
MaxDelaySec - maximum burst interval of the acoustic transmitter in seconds
TagFamily - transmitter model
Trip - sampling event
Year tagged - year behavioural measurements began
TripHaul - capture event within the sampling event
Haul - unique capture event ID
time - sampling time
Lcm - fork length (cm) measured during the sampling event
Wg - body weight (g) measured during the sampling event
fate - determined fate of the individual
D = dispersal
F = fishing mortality
P = predated
NM = natural mortality
S = survived through tracking period
T = tagging mortality
N = undedetermined
fate_date - date of mortality, or end of tracking.
sure_date - conservative evaluation with higher certainty of the date of mortality
file: Allcodpositions.rdata
description: dataset "pos" contains a list of all cod positions used in the stable isotope anaylsis
columns:
X - location in m
Y - location in m
D - depth under the surface (m), based on the pressure sensor in the transmitter
LAT - latitude for the position
LON - longitude for the position
HPE - InnovaSea/VEMCO horizontal position error
TEMP - water temperature in degrees Celcius as measured by the transmitter
Depth - repeat of column D
ID - unique identity for each cod
time - date and time of the detection, in POSIXct format, time zone UTC
day - day of detection in POSIXct format
week - week of detection in POSIXct format
hour - hour of detection in POSIXct format
min - minute of detection in POSIXct format
x - x coordinate of detection in UTM projection (m)
y - y coordinate of detection in UTM projection (m)
fate_date - the calendar date in which the assigned fate occurred.
Sharing/Access information
All data is included in this dryad upload.
Code/Software
One script including the code used to perfom the analysis and create the figures is included.
Funding
The Research Council of Norway, Award: CODSIZE 294926
Natural Sciences and Engineering Research Council
European Commission, Award: 793627
Spanish National Research Council, IF_ERC
Academy of Finland, Award: 317495
European Research Council, Award: 770884