To continue an annual series of aerial surveys off the southern Australian coast between Cape Leeuwin WA and Ceduna SA since 1993, an aerial survey was undertaken over three days, 24-29 August 2016. Because of bad weather, and for the first time in the annual series since 1993, only ‘outward’ flying legs were possible. For comparison with previous results, counts were obtained of 628 individuals including 228 calves of the year. The 2016 counts were higher than the very low count in 2015 but still below the recent trend line.
From 4305 photographic images obtained, 323 have been selected for computer-assisted ‘matching’ with those (some 7000 images of over 2000 individuals) already available in the catalogue, and 197 data sightings sheets have been added to the sightings database, currently totalling 3741 sightings sheets.
Regression analysis of log number against year for the period 1993-2016 gives increase rates for all animals of 0.0541 (95% CI 0.0371, 0.0710) equivalent to an increase of 5.55% (95% CI 3.78, 7.36) per annum, and for cow/calf pairs 0.0584 (0.0343, 0.0824) or 6.01% (3.49, 8.59) per annum, respectively.
Current population size, for this the ‘western’ Australian subpopulation, is estimated at 2195.
A Progress Report on the 2016 survey was provided on 31 December 2016.
This is the Final Report on the 2016 survey and associated activities.
News article - Southern right whale count tallies record numbers off south coast - ABC, 29 August 2017