Decadal Shifts in Southern Right Whale (Eubalaena australis) Recovery in South Australian Waters: Implications for Conservation and Management

Abstract

Southern right whales (Eubalaena australis) have shown population recovery since protection from commercial whaling and are considered a flagship species for successful conservation management. However, recovery remains incomplete, with recent evidence suggesting slowed growth and variability in reproductive success. This project used 30 years of count data in Australia (1992–2022) to investigate long-term trends in relative abundance at three key reproductive areas in South Australia. Varied rates of increase were observed, while recovery trends have moderated at the major aggregation area of Head of Bight (3.34%/year, 95% CI: 2.24, 4.44); higher growth rates were observed at Fowlers Bay, where recolonization has occurred (15.29%/year, 95% CI: 7.54, 24.33). Results support that recovery trends for the Australian population are dynamic and variable across decades. Drivers of variability may include saturation of certain areas, reoccupation of suitable habitats, spatio-temporal disturbance, and changes to factors driving migration, including body condition, prey availability, and climate change. Decadal shifts in relative abundance indicate an expanding habitat range, highlighting the importance of suitable habitat and connective migration corridors, which are increasingly important during critical life stages. Adaptive conservation management and effective threat mitigation are essential to secure recovery of this threatened species in Australia.