Responses of a polar predator to a glacier calving event

In this study, we tried to document the behavioural response of a polar marine predator to a glacier calving event in Antarctica.
We focused on Weddell seals’ (Leptonychotes weddellii) response to the calving of the Mertz Glacier Tongue in 2010, by:
i) providing a detailed description of fine-scale changes in the sea-ice landscape following the calving event;
ii) examining how these changes influenced the movement and diving behaviour of Weddell seals.

Two types of data are available in this dataset:
i) Conductivity Temperature Depth Satellite Relayed Data Loggers (CTD-SRDLs) were deployed on female Weddell seals in Terre Adélie (East Antarctica) at Dumont d'Urville Station (−66.66◦, 140.00◦) between 2006 and 2024, to study animals’ distribution and dives. The tags transmit information on their behaviour and location using the Argos satellite system. The data presented here includes the raw data transmitted by the tag, and the filtered data for analysis.
ii) Antarctic landfast ice data were obtained from NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) satellite visible and thermal infrared imagery with a spatial resolution of 1 km and a fifteen-day time stamp. Prior to March 2018, landfast ice data were taken from the dataset of Fraser et al. (2020, Earth Syst. Sci. Data, doi: 10.5194/essd-12-2987-2020). After March 2018, landfast ice maps were produced ad hoc for the Dumont d'Urville region using individual cloud-free MODIS visible and thermal infrared imagery.

Following the calving of the Mertz Glacier Tongue in February 2010, seals spent more time in Commonwealth Bay, consistent with earlier formation of landfast ice and its persistence post-calving (February 2019–2024). Landfast ice persisted in Commonwealth Bay from May onwards, although it was absent before the calving event (2006-2009). In Commonwealth Bay and west of Pointe Géologie Archipelago, seals also dived deeper after calving than before, suggesting changes in foraging strategies.

Further details on the data are presented in the Metadata file.