Animation of tagged southern right whale and vessel traffic

Brief description

This animation, embedded in the html, shows the satellite tag derived movements of the southern right whale (black track) and the Automatic Identification System (AIS) derived movements of vessels in the region (red tracks; Australian Marine Safety Authority Craft Tracking System). The whale track was interpolated to match the hourly time stamp of the AIS data (see Methods and Materials: Satellite sensor, track and ship movement analysis). The date and time for each frame (top, centre) is 'year-month-day hour:min:sec' in UTC. As part of a multi-year study of inshore movements and offshore foraging ground locations, we biopsied and satellite tagged southern right whales in Flinders Bay, Augusta, Western Australia in September 2022. Here we focus on a female with calf tagged on 9 September 2022. A transdermal Wildlife Computer SPOT-372 satellite tag that provides data on location and water temperature was deployed. To account for the spatial error associated with satellite tag derived Argos locations, we fitted a correlated random walk model using the fit_ssm function from the R package aniMotum (Jonsen et al., 2023) and estimated new locations at each of the original observed Argos location times. Travel speed was calculated using the distance (distanceTrack function from the argosfilter package; Freitas et al., 2008) and the time difference (difftime function in base R) between two consecutive locations. Vessel tracking data were downloaded from the Australian Marine Safety Authority (AMSA) Craft Tracking System (CTS). CTS collects vessel traffic data from a variety of sources, including terrestrial and satellite shipborne Automatic Identification System (AIS) data sources. We extracted vessel traffic data for the months from May to November 2022. The dataset covers the extent of Australia’s Search and Rescue Region. The southern right whale track was interpolated to match the hourly time stamp of the AIS data using the align_move function (package: moveVis (version: 0.10.5; Schwalb-Willmann et al., 2020)) and the distance between the whale and vessel locations calculated using the pointDistance function (package: raster (Hijmans R, 2023)) in R. Jonsen, I.D., Grecian, W.J., Phillips, L., Carroll, G., McMahon, C., Harcourt, R.G., Hindell, M.A., and Patterson, T.A. (2023). aniMotum, an R package for animal movement data: Rapid quality control, behavioural estimation and simulation. Methods Ecol. Evol. 14(3): 806-816. [Available at: https://doi.org/10.1111/2041-210X.14060] Freitas, C., Lydersen, C., Fedak, M., and Kovacs, K.M. (2008). A simple new algorithm to filter marine mammal Argos locations. Mar. Mammal Sci. 24: 315-325. [Available at: https://doi.org/10.1111/j.1748-7692.2007.00180.x] Schwalb-Willmann, J., Remelgado, R., Safi, K., and Wegmann, M. (2020). moveVis: Animating movement trajectories in synchronicity with static or temporally dynamic environmental data in R. Methods. Ecol. Evol. 11: 664-669. [Available at: https://doi.org/10.1111/2041-210X.13374] Hijmans, R.J. (2023). raster: Geographic Data Analysis and Modeling. R package version 3.6-26. Also see 'Harcourt, R., Sprogis, K., Gales, N.J., Andrews-Goff, V., Double, M., Besier, S., Riekkola, L., and Carrol, E.L. (2025). Stranding of a satellite-tagged southern right whale off southwest Australia. J. Cetacean Res. Manage. Special Issue 5: 45-64' for further detail.

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Notes

Purpose
This animation is described in: Harcourt, R., Sprogis, K., Gales, N.J., Andrews-Goff, V., Double, M., Besier, S., Riekkola, L., and Carrol, E.L. (2025). Stranding of a satellite-tagged southern right whale off southwest Australia. J. Cetacean Res. Manage. Special Issue 5: 45-64.