Data from: Fine-scale movement responses of free-ranging harbour porpoises to capture, tagging, and short-term noise pulses from a single airgun

van Beest, Floris M., Aarhus University

Teilmann, Jonas, Aarhus University

Hermannsen, Line, Aarhus University

Galatius, Anders, Aarhus University

Mikkelsen, Lonnie, Aarhus University

Sveegaard, Signe, Aarhus University

Dalgaard Balle, Jeppe, Aarhus University

Dietz, Rune, Aarhus University

Nabe-Nielsen, Jacob, Aarhus University

Published Nov 21, 2017 on Dryad. https://doi.org/10.5061/dryad.40nv6

Cite this dataset

van Beest, Floris M. et al. (2017). Data from: Fine-scale movement responses of free-ranging harbour porpoises to capture, tagging, and short-term noise pulses from a single airgun [Dataset]. Dryad. https://doi.org/10.5061/dryad.40nv6

Abstract

Knowledge about the impact of anthropogenic disturbances on the behavioural responses of cetaceans is constrained by lack of data on fine-scale movements of individuals. We equipped five free-ranging harbour porpoises (Phocoena phocoena) with high-resolution location and dive loggers and exposed them to a single 10 in3 underwater airgun producing high-intensity noise pulses (2−3 second intervals) for one minute. All five porpoises responded to capture and tagging with longer, faster and more directed movements as well as with shorter, shallower, less wiggly dives immediately after release, with natural behaviour resumed in ≤24 hours. When we exposed porpoises to airgun pulses at ranges of 420−690 m with noise level estimates of 135−147 dB re 1µPa2s (SEL), one individual displayed rapid and directed movements away from the exposure site and two individuals used shorter and shallower dives compared to natural behaviour immediately after exposure. Noise-induced movement typically lasted for ≤8 hours with an additional 24-hour recovery period until natural behaviour was resumed. The remaining individuals did not show any quantifiable responses to the noise exposure. Changes in natural behaviour following anthropogenic disturbances may reduce feeding opportunities and evaluating potential population-level consequences should be a priority research area.

Usage notes

Exposed porpoise GPS data

This is the full dataset collected by GPS tags fitted on four harbor porpoise individuals. Large positional errors were removed as described in the article. The data also contains the calculated horizontal movement parameters and distance variables to produce figure 1 in the main article and the figures in the Supplementary material. The data contains 10 variables: “id” gives the name of the harbor porpoise individual “datetime” gives the date and time of the GPS location columns “x” and “y” are the coordinates of the GPS location in the projection CRS("+proj=utm +zone=32 +ellps=intl +towgs84=-87,-98,-121,0,0,0,0 +units=m +no_defs") “steplength” is the Euclidian distance (m) between GPS locations “speed” is the speed (m/sec) between GPS locations “turing_angle” is the turning angle (degrees) between GPS locations “hour_since_release” is the time (hours) since the individual was released into the water after GPS tagging “dist_to_exposure_site” is the Euclidian distance (m) of the individual porpoise relative to the airgun exposure site “dist_to_release_site” is the Euclidian distance (m) of the individual porpoise relative to the GPS tagging and release site

raw_data_horizontal_movements_160503.txt

Exposed porpoise dive data

This is the full dataset collected by dive-loggers fitted on four harbor porpoise individuals. Impossible values were removed as described in the article. It is the underlying data used to produce figures in the Supplementary material and contains 6 variables: “id” gives the name of the harbor porpoise individual “datetime” gives the date and time of the start of each dive “dive_duration” gives the difference in time (sec) between the start and end of each dive “max_depth” provides the maximum depth (m) reached during each dive “wiggliness” provides the sum of absolute depth differences (m) while at the bottom of each dive; measure of amount of “wiggling” while at bottom “post_dive_duration” provides the time (sec) spent at the surface after each dive

raw_data_vertical_movements_160503.txt

residual_data_horizontal_movements

Contains the residuals of the GAM analyses on the horizontal movement data, which was used in the piecewise regression analyses. It is the underlying data used to produce figure 3 in the main article and contains 5 variables: “id” gives the name of the harbor porpoise individual “hour_since_release” is the time (hours) since the individual was released into the water after GPS tagging “residuals_steplength” are the residuals of the Euclidian distance (m) between GPS locations “residuals_speed” are the residuals of the speed (m/sec) between GPS locations “residuals_turing_angle” are the residuals of the turning angle (degrees) between GPS locations

residual_data_vertical_movements

Contains the residuals of the GAM analyses on the vertical movement data, which was used in the piecewise regression analyses. It is the underlying data used to produce figure 4 in the main article and contains 6 variables: “id” gives the name of the harbor porpoise individual “hour_since_release” is the time (hours) since the individual was released into the water after GPS tagging “dive_duration” are the residuals of the difference in time (sec) between the start and end of each dive “max_depth” are the residuals of the maximum depth (m) reached during each dive “wiggliness” are the residuals of the sum of absolute depth differences (m) while at the bottom of each dive “post_dive_duration” are the residuals of the time (sec) spent at the surface after each dive

R-code

The file contains the R-code for the piecewise linear regression analyses and model selection used to assess capture/tagging and airgun noise-induced movement responses in harbour porpoises

Location

Inner Danish Waters