2.4.14 Whales

Approximately 15 species of whales are known to occur within the Region. The two most commonly encountered species are the humpback and the dwarf minke whale.500,501 Sightings of killer whales, false killer whales, short-finned pilot whales and various beaked whales have been recorded in the Region. Habitat use and the extent to which these species are resident within the Region remain important knowledge gaps. All species of whales within the Region are protected by legislation.502

Several Traditional Owner groups along the coast, such as the Woppaburra people of the Keppel Islands, regard whales (Mugga Mugga) as totemic species.78 Humpback and dwarf minke whales are economically important to the Region, as reliable and extremely popular tourist attractions. The only known predictable aggregation of dwarf minke whales in the world can be found in the northern Great Barrier Reef each winter.503 Due to their small size and cryptic behaviour, dwarf minke whales are difficult to study, and the size of their population is unknown.

An underwater image of two dwarf minke whales swimming underneath a group of tourist that are snorkelling while holding on to a rope.
Minke whales are a tourist attraction as they travel through the Reef each winter. © Matt Curnock 2022

Since the most recent surveys in 2015, the humpback whale population may have increased to a projected 40,000 animals, making the east Australian humpback population one of the largest humpback whale populations globally.504 This exceptional recovery of the population was one of the reasons humpback whales were removed from Australia’s threatened species list in 2022.505

Humpback whale populations have recovered strongly

Threats to individual whales include entanglement in fishing and shark-control nets, ship strikes and underwater noise.506 The risk for humpback whales of getting entangled in nets or struck by ships is projected to increase three- to five-fold over the next 10 years due to their increase in numbers.506 On a population level, the biggest threat to whales is changes in food availability in the Southern Ocean due to climate change.507 Information on disease or parasites is generally unavailable, but disease incidence in humpback whales is likely to increase as the population approaches carrying capacity.508 The extent of interactions between populations is an important knowledge gap with implications for understanding drivers and risks to the condition of whale populations in the Region.509 Populations of whale species within the Region are inferred to be stable. Humpback whales have recovered strongly. Climate change is the greatest threat to whale populations and their food sources outside the Region.

  • 78. Great Barrier Reef Marine Park Authority 2021, Woppaburra Traditional Owner heritage assessment (Document No. 100428), Great Barrier Reef Marine Park Authority.
  • 500. Rizzo, L.Y. and Schulte, D. 2009, A review of humpback whales' migration patterns worldwide and their consequences to gene flow, Journal of the Marine Biological Association of the United Kingdom 89: 995-1002.
  • 501. Meynecke, J., De Bie, J., Barraqueta, J.M., Seyboth, E., Dey, S.P., et al. 2021, The role of environmental drivers in humpback whale distribution, movement and behavior: A review, Frontiers in Marine Science 8: 720774.
  • 502. Foley, H.J., Pacifici, K., Baird, R.W., Webster, D.L., Swaim, Z.T., et al. 2021, Residency and movement patterns of Cuvier’s beaked whales Ziphius cavirostris off Cape Hatteras, North Carolina, USA, Marine Ecology Progress Series 660: 203-216.
  • 503. Arnold, P.W. 1997, Occurrence of dwarf minke whales (Balaenoptera acutorostrata) on the northern Great Barrier Reef, Australia, Report of the International Whaling Commission 47: 419–424.
  • 504. Noad, M.J., Kniest, E. and Dunlop, R.A. 2019, Boom to bust? Implications for the continued rapid growth of the eastern Australian humpback whale population despite recovery, Population Ecology 61(2): 198-209.
  • 505. Threatened Species Scientific Committee 2022, Listing advice – Megaptera novaeangliae – humpback whale, Department of Agriculture, Water and Environment, Canberra.
  • 506. Smith, J.N., Kelly, N., Childerhouse, S., Redfern, J.V., Moore, T.J., et al. 2020, Quantifying ship strike risk to breeding whales in a multiple-use marine park: the Great Barrier Reef, Frontiers in Marine Science 7: 67.
  • 507. Albouy, C., Delattre, V., Donati, G., Frölicher, T.L., Albouy-Boyer, S., et al. 2020, Global vulnerability of marine mammals to global warming, Scientific Reports 10(1): 548.
  • 508. Fowler, C.W. 1990, Density dependence in northern fur seals (Callorhinus ursinus), Marine Mammal Science 6(3): 171-195.
  • 509. Pirotta, V., Franklin, W., Mansfield, L., Lowe, J. and Peterson, O. 2023, Sighting records of “Migaloo” the white humpback whale provide evidence of Australian site fidelity and use of New Zealand waters as a migratory route, Australian Zoologist 42(4): 1014-1028.