Ocean wanderers: satellite telemetry-derived movements and habitat use of Southern right whales (Eubalaena australis) in the western South Atlantic

ZERBINI, ALEXANDRE; FERNÁNDEZ, SANTIAGO JOSÉ; CRESPO, E. A.; COSCARELLA, M. A.; GONZÁLES, RAÚL

Honolulu

Simposio; 7TH INTERNATIONAL BIO-LOGGING SCIENCE SYMPOSIUM; 2021

NOAA

Southern right whales (SRWs, Eubalaena australis), once depleted to near extinction by whaling and now recovering and reoccupying historical habitats, are susceptible to environmental changes in their entire home range. Therefore, understanding how their large-scale movements and foraging habits change due to climate variability is critical to enhance conservation and ensure their long-term survival. Between 2014 and 2019, location-only (n=33) and archival (n=6) Argos satellite transmitters were deployed on SRWs in the northern Patagonian gulfs off Argentina, the species? main calving ground in the western South Atlantic. The goals were to assess their movements, migratory routes and destinations, and their habitat use in the feeding grounds. Instruments were deployed on solitary individuals (n=23) and mothers with calves (n=13). Movement models were used to standardize tracks and assess areas of higher use throughout the migratory cycle. Average transmission duration was 115 days (range=18-237) for location-only tags and 95 days (range=71-126) for archival tags. Satellite tracking revealed novel and unique movement patterns of SRWs at various scales. Residency times and occupancy patterns of solitary individuals and mothers with calves in the Patagonian gulfs of Argentina differ, with the mothers showing more restricted movements and longer residency. Some individual SRWs migrated close to shore along the coast of Argentina before moving offshore towards feeding habitats, suggesting the use of other coastal foraging areas within the breeding grounds. Feeding destinations were identified in the Patagonian shelf from 35 to 52oS, the western South Atlantic basin, the Scotia Sea, and the northern Weddell Sea. The use of open-ocean middle-latitude oceanographic features, presumably for feeding, was also observed. This study provides unprecedented details of the movements of SRWs in multiple potential feeding grounds in the South Atlantic within each season.