Movements and behaviour of southern right whales satellite-tracked in and beyond a subantarctic archipelago wintering ground

Abstract

The post-exploitation recovery of the south-west Atlantic southern right whale (SRW, Eubalaena australis) population has been affected by widespread calf mortalities, resulting in the development of an International Whaling Commission Conservation Management Plan (IWC-CMP). The coastal waters around the Falkland Islands (Malvinas) comprise a recently documented wintering ground for the population. In July 2022, we deployed satellite tags on 10 SRWs to better understand their occurrence around the islands and their connectivity with other geographic regions. The animals remained in the islands for 1 to 57 d following tagging. High-use habitats comprised waters <10 km off the north and north-east coasts of East Falkland, where they exhibited slow and varied movements consistent with breeding and social behaviours. Six whales, including all 3 confirmed females, subsequently continued to the major calving ground located at Peninsula Valdés (Argentina), where they remained for up to 84 d. During spring, almost all tagged whales utilised the Patagonian Shelf (70-140 m depth) as a foraging habitat. Three males travelled south-east after departing the islands and variously visited higher latitude foraging grounds including the South Orkney and South Shetland islands, Scotia Sea and Antarctic Peninsula. Telemetry provided valuable information on the spatial and temporal extent to which SRWs aggregate in Falkland Islands (Malvinas) waters during winter and supports growing evidence that the region is a high-use critical habitat supporting breeding behaviour. The region should be incorporated into future region-wide conservation efforts for the south-west Atlantic SRW population and merits recognition in the IWC-CMP.