The End of an Era? Trends in Abundance and Reproduction of Australian Southern Right Whales (Eubalaena australis) Suggest Failure to Re-Establish Pre-Whaling Population Size
Anne Grundlehner, Joshua N Smith, John L Bannister, Virginia Andrews-Goff, Madeleine Brasier, Micheal C Double and Stuart P Corney
aerial surveys baleen whales Bayesian statistics exploitation marine environment marine mammals population dynamics population recovery Southern Ocean whaling
The large-scale exploitation of whale populations in the whaling era led to the near extirpation of large whales all over the world. This must have had major repercussions for marine ecosystems globally. Consequent changes to those ecosystems and physical environments create uncertainty around whether present-day conditions are adequate to support full recovery of pre-whaling population sizes. Combined with potential effects of anthropogenic stressors, the future viability of exploited whale populations is questioned. This migrating species was left near extinction from whaling and has shown slow, yet steady, recovery in recent decades. Here, we collate abundance data from aerial surveys performed along the Australian coast between 1976 and 2024, covering 2250 km of coastal habitat, to study the recovery trajectory of Australian southern right whales (Eubalaena australis). We describe temporal trends in abundance, reproduction and growth of the western sub-population. Our study reveals that despite previously displaying exponential growth, and a present population size still residing far below pre-whaling levels, our annual births have started declining since 2016 and annual abundances of unaccompanied individuals have dropped by 66%. Our results suggest the end of an era of this population's recovery, highlighting that an initial period of steady recovery does not guarantee successful re-establishment of previous abundance levels.
Details
Title
The End of an Era? Trends in Abundance and Reproduction of Australian Southern Right Whales (Eubalaena australis) Suggest Failure to Re-Establish Pre-Whaling Population Size
Authors/Creators
Anne Grundlehner - University of Tasmania
Joshua N Smith - Australian Antarctic Division
John L Bannister - Australian Museum
Virginia Andrews-Goff - Australian Antarctic Division
Madeleine Brasier - University of Tasmania
Micheal C Double - Australian Antarctic Division
Stuart P Corney - University of Tasmania
Publication Details
Global change biology, Vol.31(5), e70218
Publisher
WILEY
Number of pages
16
Grant note
Commonwealth Department of Australia
Research Scholarship and John Bannister Memorial Top-Up provided through the University of Tasmania
National Environmental Science Program via the Marine Biodiversity Hub and Marine Coastal Hub
The Island Foundation