Population Estimate and Rate of Increase of Southern Right Whales, Eubalaena australis in South-eastern Australia In prep.
Stamation, K., Watson, M, Moloney, P, Charlton, C and Bannister, J.
Southern right whales, Eubalaena australis in Australian waters form two genetically distinct populations: a western population in South Australia and Western Australia; and an eastern population in south-eastern Australia (Tasmania, Victoria and New South Wales). Although delineation of the two populations is complex, due to mixing in the migratory corridor, they show contrasting patterns of recovery since whaling ceased. Here we provide an abundance estimate, derived from a superpopulation mark recapture model, for the south-eastern Australian southern right whale population of 268 individuals (68 breeding females) that is increasing at a rate of 4.7% per annum, between years 1996-2017. There was no significant change over the last three decades in the annual abundance of cow-calf pairs sighted at the only recognised calving ground in south-eastern Australia (Logans Beach in Warrnambool, Victoria). This study provides the first complete estimate of population size and rate of increase of southern right whales using the south-eastern Australian coastline and is a key step in understanding population increase of southern right whales in south-eastern Australia. This knowledge is critical for assessment of population status and recovery of southern right whales off Australia.