Aerial surveys of southern right whales (Eubalaena australis) were undertaken off the southern Australian coast to monitor the recovery of this endangered species following extreme 19th and 20th Century commercial whaling. The aerial survey was undertaken in the coastal waters from Perth (Western Australia) to Ceduna (South Australia) between the 12th and 17th August 2021, to maintain the annual series of surveys and inform the long-term population trend. The maximum whale counts for each leg of the survey flights between Cape Leeuwin and Ceduna, and consisted of a total 643 southern right whales sighted across the survey area (270 cow-calf pairs and 103 unaccompanied whales). The subsequent population estimate for the Australian ‘south-western’ population is 2,549 whales, which represents the majority of the Australian population given the very low numbers in the ‘south-eastern’ subpopulation. The population long-term trend data is indicating recent years (from 2007) are showing greater inter-annual variation in whale counts. To evaluate the recovery of the southern right whale population, it will be critical to collect long-term data on the annual variability in whale numbers related to the non-annual female breeding cycle and identify possible impacts on this by short-term climate dynamics, longer-term climate change and/or anthropogenic threats.

Annual aerial surveys of southern right whales have been conducted off the southern Australian coast, between Cape Leeuwin (W.A.) and Ceduna (S.A.) over a 28 year period between 1993 and 2020, to monitor the recovery of this species following commercial whaling. We conducted an aerial survey of southern right whales between the 20th and 24th August 2020, to continue these annual series of surveys and inform the long-term population trend. The comparable count for the 2020 survey utilised the maximum count for each leg and incorporated a correction for the unsurveyed area between Head of the Bight to Ceduna due to the inability to cover whole survey as a result of COVID-19 restrictions between State borders. This resulted in 384 individuals, consisting of 156 cows accompanied by calves of the year and 72 unaccompanied adults. Of these, 126 images of individual whales have been selected for photo-identification matching. This is a significant decrease in overall sightings that has not been observed for over 13 years when compared to long term trend data for the population; last seen in 2007 (N = 286 individuals). The subsequent population estimate for the Australian ‘western’ subpopulation is 2,585 whales, which is also a significant decrease in estimated population size from 3,164 in 2019 to 2,585 in 2020. The extremely low number of unaccompanied adults (N = 68) had the greatest impact on the overall number of sightings in 2020, and is the lowest number sighted since 1993 (N = 47). Previous surveys in 2007 and 2015 have been noted as years of low whale counts that had been deemed anomalous years, although the low numbers from this survey questions this and may suggest the 3-year female breeding cycle is becoming more unpredictable. Considerable inter-annual variation in whale numbers, and cycles in population growth, makes it difficult to detect consistent and reliable changes in abundance from one year to the next, or even over longer periods of time. This severely inhibits our ability to identify immediate threats to the population and strongly supports continued annual population surveys.

This dataset is a collection of dedicated humpback whale sightings and effort from a double platform line transect aerial survey program conducted in the Great Barrier Reef. The survey was undertaken 3-10 August 2012 using a Partenavia Observer P-68B six-seater, twin engine, high-wing aircraft at a ground speed of 100 knots in passing mode at an altitude of 1000 ft. The survey was undertaken to coincide with peak humpback whale abundance within the breeding season, when it is assumed whales are utilising habitat important to their breeding behaviour and not engaging in migratory behaviour. For more details of the survey see: Smith, J. N., N. Kelly, and I. W. Renner. 2020. Validation of presence-only models for management applications: humpback whale breeding grounds in the Great Barrier Reef World Heritage Area. Ecological Applications. Accepted. Smith, J. N., Kelly, N., Childerhouse, S., Redfern, J. V., Moore, T. J. and Peel, D. (2020) Quantifying ship strike risk to breeding whales in a multiple-use marine park: the Great Barrier Reef. Frontiers in Marine Science 7:1-15. doi: 10.3389/fmars.2020.00067 Data were collected under the Australian Marine Mammal Grant Program for project 11/15 ‘Identification of humpback whale breeding grounds in the Great Barrier Reef: validation of a spatial habitat model’.

This dataset is a collection of aerial images taken from a camera mounted in the fuselage of the CASA-212 400 aircraft used to survey for pygmy blue whales. Line transect data from that survey are also available (but see Gill, P.C., Pirzl, R., Morrice, M.G. and Lawton, K. (2015). "Cetacean diversity of the continental shelf and slope off southern australia." The Journal of Wildlife Management 79(4): 672-681 for more details). The digital images were taken with a Nikon D200 camera, using a 35mm lens. The survey altitude was approximately 1500 ft. Images have full EXIF data attached. Image footprints are approximately 204 m along-track by 306 m across track, with some image overlap. Aerial images; downward facing images along track from a line transect survey. There are ~41K jpeg images. Images taken with Nikon D200 camera, with 35 mm lens. Aerial survey altitude was approximately 1500 ft. Each image has a water-surface footprint of 204 m along-track by 306 m across track; there is some image overlap along-track. The EXIF data for each image is populated. Images taken in January 2012 along the Bonney Upwelling, along the south-east coast of Australia, an area known to be a summer (Nov-May) feeding ground for pygmy blue whales; the surveys focussed on the area bounded by 138.0-145.0ºE and 36.6-40.3ºS.