Southern Australian Coastal and Shelf Region IMMA

Size in Square Kilometres

258,364 km2

Qualifying Species and Criteria

Australian Sea Lion – Neophoca cinerea

Criterion A; B (2); C (1, 2); D(1)

Australian fur seal –Arctocephalus pusillus doriferus

Criterion C(2)

New Zealand fur seal – Arctocephalus forsteri

Criterion B(2) ; C(1,2)

Southern right whale – Eubalaena australis

Criterion B(2) ; C(1,3)

Antarctic blue whale – Balaenoptera musculus intermedia

Criterion B(2) ; C(2)

Pygmy blue whale – Balaenoptera musculus brevicauda

Criterion A ; B(2) ; C(2)

Marine Mammal Diversity 

Megaptera novaeangliae, Tursiops aduncus, Tursiops truncatus, Delphinus delphis, Tasmacetus shepherdi, Mesoplodon layardii, Orcinus orca, Caperea marginata, Mirounga leonina, Hydrurga leptonyx, Arctocephalus tropicalis, Balaenoptera borealis

Download factsheet


The Southern Australian coastal and shelf region IMMA is home to the largest density of marine mammals, seabirds, sharks and large pelagic fish species of any other shelf ecosystem in Australia. The region is of national and international significance for marine mammals and provides important habitat for critical activities such as breeding and foraging. Seasonal coastal upwelling along the Bonney Coast and off Kangaroo Island and lower Eyre Peninsula creates zones of high productivity, supporting plankton, pelagic fish and squid, and thus important prey for marine mammals within these regions. The IMMA is critical for Australian pinnipeds, hosting over 80% of the global population of Australian sea lions, over 80% of Australia’s New Zealand fur seal population, and important breeding sites for Australian fur seals.

The IMMA also serves as habitat for up to 40% of the Australian population of southern right whales, or ~10% of global abundance, as well as Australia’s largest feeding aggregation of pygmy blue whales, which occurs in mid-shelf and slope waters off Kangaroo Island, South Australia and in the Bonney Upwelling off Portland, Victoria during summer and autumn.

Description of Qualifying Criteria

Criterion A – Species or Population Vulnerability

The IMMA contains habitat important for the survival and recovery of the Critically Endangered Antarctic blue whale, the Endangered pygmy blue whale and Endangered Australian sea lion. The IMMA also provides critical habitat for a globally significant proportion of southern right whales.

Criterion B: Distribution and Abundance

Sub-criterion B2: Aggregations

The IMMA includes Australia’s largest feeding aggregation of Antarctic blue whales and pygmy blue whales, that occur in mid-shelf and slope waters of the eastern GAB, that occur during summer and autumn off Kangaroo Island and in the Bonney Upwelling  primarily between the 50-150m depth contour (Gill et al. 2015). The current global population of blue whales is uncertain but is plausibly in the range of 5-15,000 (Cooke 2018). For the pygmy blue whale there is uncertainty in population numbers pre-exploitation, and their current numbers are not known. Pygmy and Antarctic blue whales were acoustically detected in the Bonney Upwelling (McCauley et al. 2018). Calls from Antarctic blue whales are typically recorded between November and May, though calls have been recorded as late as June.

The Australian sea lion is the only endemic pinniped that breeds in Australia, and the least abundant. The IMMA is exceptionally important to the Australian sea lion population, supporting 50% of the species that breed on offshore islands and forage in coastal waters between Kangaroo Island and Bunda Cliffs, South Australia (Goldsworthy et al. 2015). Regional trends in aggregated abundance between 2005–2015 show a decline of 2.9% per year or 4.3% per breeding season for the Bunda Cliff area (Goldsworthy et al. 2015). The IMMA also includes >80% of the New Zealand fur seal (Arctocephalus forsteri) population in Australia that breeds on the south coast of Kangaroo Island and on islands off lower Eyre Peninsula.

The established aggregation area at the Head of Bight is the largest calving and nursery area for southern right whales in Australia (Charlton et al. 2019b, DSEWPAC 2012). In Australia, the south western sub-population comprises most of the Australian population and was estimated at around 3,200 individuals in 2018, increasing at an annual rate of approximately 6% per annum (Bannister 2017, Smith et al. 2019). Head of Bight represents up to 40% of the Australian total population (Burnell 2001, Charlton et al. 2019a) or ~10% of global abundance (IWC 2013). Annual abundance at the Head of the Bight frequently exceeds 200 unique individuals photo identified between July and September (Charlton et al. 2019a). The area is occupied by 80% female and calf pairs and 20% unaccompanied whales and mean residency times include 65 days for females with a calf and 15 days for unaccompanied whales (Charlton 2017). Recent studies demonstrated that the primary calving ground has reached saturation capacity due to density dependence, resulting in increased abundance and habitat shifts into adjacent habitat, such as Fowlers Bay (170 km to the south east) (Charlton et al. 2019b).

Southern right whales in the IMMA belong to the south eastern and south western Australian sub-populations, for which there is some evidence of genetic differentiation (Carroll et al. 2011). Warrnambool is a small established aggregation area and Portland, Port Fairy, Port Campbell and Peterborough are emerging breeding aggregation areas for southern right whales in the south eastern sub-population. Systematic aerial surveys and opportunistic photo identification studies have been completed in the area since the 1990s. The population is currently estimated at less than 300, with no signs of increase in these emerging aggregation areas (DSEWPaC 2012; Watson et al. 2015). Photo identification studies have recorded thirteen breeding females with site fidelity to the Logans Beach, Warrnambool, though no significant change has been seen in the annual abundance of mother-calf pairs over the last three decades (Stamation et al. 2020). The high marine traffic and oil and gas industry in the area, and the vulnerability of the south eastern sub-population makes the protection of the area encompassed in this IMMA critical to the sub-population’s survival.

Threatened marine mammals occur regularly in this area and are concentrated to an such extent that a single large-scale event could significantly affect the long-term survival of Australian sea lions as well as pygmy blue whales and southern right whales within the southwestern Pacific region.

Criterion C: Key Life Cycle Activities

Sub-criterion C1: Reproductive Areas

The IMMA includes haulout sites and foraging grounds used by more than one pinniped population for breeding, nursing and mating. Australian sea lions breed on offshore islands and forage in coastal waters between Kangaroo Island and Bunda Cliffs. Long-nosed fur seals breed on the south coast of Kangaroo Island and on islands off lower Eyre Peninsula (Goldsworthy 2015).

The major calving and nursery aggregation areas for southern right whales at the Head of Bight and Fowlers Bay in the cIMMA provide specific sites for giving birth and caring for young and are of national and global significance. Annual calf numbers in the Head of Bight, Fowlers Bay area regularly exceed 100 calves (Charlton et al. 2019a; Charlton et al. 2019b). Logans Beach, Warrnambool is the only established calving aggregation area for southern right whales in the south east of Australia and was described as critical to survival of the what? in the Conservation Management Plan for the Southern Right Whale (DSEWPAC 2012). Small emerging aggregation areas occur in Port Fairy, Portland, Port Campbell and Peterborough in Victoria.

Sub-criterion C2: Feeding Areas

Australia’s largest feeding aggregation of pygmy blue whales and Antarctic blue whales occurs in mid-shelf and slope waters off Kangaroo Island and in the Bonney Upwelling during summer and autumn. The Bonney Coast Upwelling is one of only two identified seasonal feeding areas for blue whales in Australian coastal waters and is one of 12 known blue whale feeding aggregation areas globally.

The time and location of the appearance of blue whales in the east generally coincides with the upwelling of cold water in summer and autumn along this coast (the Bonney Upwelling) and the associated aggregations of krill that they feed on (Gill and Morrice, 2003). Gill et al. (2011) also reported that 80% of blue whale sightings were encountered in water depths between 50 and 150 m, 93% in water depths <200 m and 10% within 5 km of the 200 m isobath in the eastern and central zones.

The IMMA includes critical foraging habitat for Australian sea lions, which forage in coastal waters between Kangaroo Island and the Bunda Cliffs. These sea lions use a variety of shoreline types, but prefer the more sheltered sides of islands and typically avoid rocky exposed coasts (Shaughnessy, 1999). They are considered to be specialised benthic foragers, i.e. they feed primarily on the shelf sea floor (DSEWPaC, 2013c). Australian sea lions feed on the continental shelf, most commonly in depths of 20–100 m, with adult males foraging further offshore and into deeper waters (DSEWPaC, 2013). They typically forage up to 60 km from their colony,but can travel up to 190 km when over shelf waters (Shaughnessy, 1999).

New Zealand fur seals in South Australia feed on a wide variety of fish, cephalopods and crustaceans. Adult males forage at the edge of the continental shelf, adult females typically use continental shelf or near-shelf waters in summer and autumn, and pelagic waters associated with the subtropical front much further south during winter, the same region that is favored by juveniles. During summer, females and juveniles forage closer to their breeding colony while moulting and, in the case of females, while feeding small pups. (Page et al. 2006, Baylis et al. 2008, Foo et al. 2019).

Sub-criterion C3: Migration Areas

The coastal zone from 0-2km from shore along the entire south coast of Australia represents important coastal movement zones and corridors for southern right whales. The movement of southern right whales between coastal aggregation areas within and across seasons, shows that the corridor between the aggregation areas is important connective habitat (Burnell, 2001; Pirzl et al. 2009).  Results support the view that greater abundance promotes increased linkage via connective corridors between aggregation areas (Charlton et al. 2019b). Within year movements averaged 730 km, over 34 days. The maximum reported within-season movement of an individual southern right whale across coastal southern Australia is 1,490 km.

Sub-criterion D1: Distinctiveness

Australian sea lions are endemic to Australia, occurring in coastal habitats within Western Australia and South Australia. They are unique in having large numbers of small breeding colonies, low reproductive rates, an unusually long breeding cycle (17-18 months), high site fidelity, and poor dispersal (Campbell et al. 2008).

Sub-criterion D2: Diversity

Diversity of habitats and oceanographic conditions in the IMMA provide for one of the most biodiverse regions in Australia for marine mammals. A minimum of eleven marine mammal species are known to occur in the IMMA, including cetaceans: southern right, humpback, pygmy and Antarctic blue, sei, pygmy right and killer whales, common, Indo-pacific and common bottlenose dolphins, Shepard’s and strapped-toothed beaked whales; and pinnipeds: Australian fur and New Zealand fur seals; and Australian sea lions.

The area is also important for humpback whales moving through the area or migrating to northern breeding grounds on the east or the west coast. Sightings and beach-washed carcasses are widely distributed throughout southern Australia from the Victorian border to the Head of the Bight, suggesting they are presence not infrequently (Kemper 2005). Ward et al. (2019) recorded humpback whale song in nearshore waters off Fowlers Bay annually during acoustic monitoring program during 2014-2017.

The coastal area and bays also represent important habitat for large populations of coastal common and bottlenose dolphins. There is some evidence for genetic differentiation of bottlenose dolphins in the southeast of Australia; the Burrunan dolphin, Tursiops cf. australis, represents a lineage of bottlenose dolphins that may eventually be recognized as a different species endemic to southern Australian coastal waters (Charlton-Robb et al. 2011).

Supporting Information

Attard, C. R. M., L. B. Beheregaray, J. Sandoval‐Castillo, C. S. Jenner, P. C. Gill, M. N. M. Jenner, M. G. Morrice, and L. M. Moller. (2018). From conservation genetics to conservation genomics: a genome‐ wide assessment of blue whales (Balaenoptera musculus) in Australian feeding aggregations. Royal Society Open Science 5(1):170925.

Bailleul, F., Goldsworthy, S.D., Rogers, P.J., Mackay, A.I., Jonsen, I., Hindell, M. And Patterson, T. (2017). Identifying Biologically Important Areas For Iconic Species And Apex Predators In The Great Australian Bight. Final Report Gabrp Project 4.2. Great Australian Bight Research Program, GABRP Research Report Series Number 23, 116pp.

Bannister, J. L., (2017). Project A7- Monitoring Population Dynamics of ‘Western’ Right Whales off Southern Australia 2015-2018. Final report to National Environment Science Program, Australian Commonwealth Government.

Bilgmann, K., Parra, G.J., Holmes, L., Peters, K. J., Jonsen, I. D. And Möller, L.M (2019) Abundance Estimates And Habitat Preferences Of Bottlenose Dolphins Reveal The Importance Of Two Gulfs In South Australia. Scientific Reports 9:8044

Bilgmann, Kerstin, Guido J. Parra, And Luciana M. Möller. “Occurrence, Distribution And Abundance Of Cetaceans Off The Western Eyre Peninsula In The Great Australian Bight.” Deep Sea Research Part Ii: Topical Studies In Oceanography 157 (2018): 134-145.

Burnell, S. R. (2001). Aspects of the reproductive biology, movements and site fidelity of right whales off Australia. 2, 89-102.

Campbell, R. A., Gales, N. J., Lento, G. M. & Baker, C. S. (2008). Islands in the sea: extreme female natal site fidelity in the Australian sea lion, Neophoca cinerea. Biology Letters, 4, 139-142.

Carroll, E., N. Patenaude, A. Alexander, D. Steel, R. Harcourt, S. Childerhouse, S. Smith, J. Bannister, R. Constantine & C. Scott Baker (2011). Population structure and individual movement of southern right whales around New Zealand and Australia. Marine Ecology Progress Series. 432:257-68.

Charlton, C., Ward, R., McCauley, R. D., Brownell Jr., R. L., Salgado Kent, S., & Burnell, S. (2019a). Southern right whale (Eubalaena australis), seasonal abundance and distribution at Head of Bight, South Australia. Aquatic Conservation: Marine and Freshwater Ecosystems 29, 576–588.

Charlton, C., Ward, R., McCauley, R. D., Brownell Jr., R. L., Guggenheimer, S., Salgado Kent S., & Bannister, J. L. (2019b). Southern right whales (Eubalaena australis) return to a former wintering calving ground: Fowlers Bay South Australia. Marine Mammal Science, 35(4), 1438-1462.

Charlton, C. M. (2017). Population demographics of southern right whales (Eubalaena australis) in southern Australia. Ph.D. thesis. Curtin University, Centre for Marine Science and Technology, Perth, Australia. 171 pp.

Charlton-Robb, K., Gershwin, L.A., Thompson, R., Austin, J., Owen, K. and McKechnie, S., 2011. A new dolphin species, the Burrunan dolphin Tursiops australis sp. nov., endemic to southern Australian coastal waters. Plos one, 6(9).

Commonwealth of Australia (CoA) (2015). Conservation Management Plan for the Blue Whale – A Recovery Plan under the Environment Protection and Biodiversity Conservation Act 1999 Available from: -4e5d-abff-11cac2ebc486/files/blue-whale-conservation-management-plan.pdf.

Cooke, J.G. 2018. Balaenoptera musculus . The IUCN Red List of Threatened Species 2018: e.T2477A50226195. Downloaded on 14 February 2020.

Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC) (2012). Conservation Management Plan for the Southern Right Whale: A Recovery Plan under the Environment Protection and Biodiversity Conservation Act. 1999 (2011–2021), Available at:

Expert Panel On A Declared Commercial Fishing Activity (2014) Report Of The Expert Panel On A Declared Commercial Fishing Activity (Small Pelagic Fishery) Declaration 2012. Department Of The Environment: Canberra. 292pp.

Gill, P.C., M.G. Morrice, B. Page, R. Pirzl, A.H. Levings and M. Coyne (2011). Blue whale habitat selection and within-season distribution in a regional upwelling system off southern Australia. Marine Ecology Progress Series, 421: 243–263. Available from:

Gill, P. and M. Morrice (2003). Cetacean Observations. Blue Whale Compliance Aerial Surveys. Santos Ltd Seismic Survey Program Vic/P51 and P52. November – December 2002. Report to Santos Ltd.

Groom, C.J. And Coughran, D.K. (2012). Three Decades Of Cetacean Strandings In Western Australia: 1981 To 2010. Journal Of The Royal Society Of Western Australia 95: 63-76

Groom, C.J., Coughran, D.K. And Smith, H.C. (2014). Records Of Beaked Whales (Family Ziphiidae) In Western Australian Waters. Marine Biodiversity Records, 7. Doi: 10.1017/S1755267214000475.

Goldsworthy, S. D., Page, B., Shaughnessy, P. D., & Linnane, A. (2010). Mitigating Seal Interactions In The SRLF And The Gillnet Sector SESSF In South Australia. Report to The

Fisheries Research And Development Institute. South Australian Research And Development Institute (Aquatic Sciences), Adelaide. Sardi Publication No. F2009/000613-1, SARDI Research Report Series No. 405.

Goldsworthy Sd, Bulman C, He X, Larcombe J, Littnan C (2003) Trophic Interactions Between Marine Mammals And Australian Fisheries: An Ecosystem Approach. In: Gales N, Hindell M, and Kirkwood R. (Eds) Marine Mammals And Humans: Fisheries, Tourism And Management. CSIRO Publications. Pp. 62-99

Goldsworthy, S. D., Mackay, A. I., Bilgmann, K., Möller, L., Parra, G., Gill, P., Bailleul, F., Shaughnessy, P. D., Reinhold, S.-L. and Rogers, P. J. (2017). Status, distribution, and abundance of iconic species and apex predators in the Great Australian Bight. Great Australian Bight Research Program, Great Australian Bight Research Report Number 15, 229pp.

Kemper, C. (2005) Records of humpback whales (Megaptera novaeangliae) in South Australia. Transactions of the Royal Society of South Australia 129:53-58.

McCauley, R. D., A. N. Gavrilov, C. D. Jolliffe, R. Ward and P. C. Gill. (2018). Pygmy blue and Antarctic blue whale presence, distribution and population parameters in southern Australia based on passive acoustics. Deep-Sea Research Part II 157–158:154–168pp.

Passadore, C., L. Möller, F. Diaz-Aguirre, and G. J. Parra. (2018). High site fidelity and restricted ranging patterns in southern Australian bottlenose dolphins. Ecology and Evolution 8:242-256.

Passadore, C., L. Möller, F. Diaz‐Aguirre, and G. J. Parra. (2017). Demography of southern Australian bottlenose dolphins living in a protected inverse estuary. Aquatic Conservation: Marine and Freshwater Ecosystems 27:1186-1197.

Passadore, C., L. M. Möller, F. Diaz-Aguirre, and G. J. Parra. (2018). Modelling Dolphin Distribution to Inform Future Spatial Conservation Decisions in a Marine Protected Area. Scientific Reports 8:15659.

Pirzl, R., Patenaude, N. J., Burnell, S. and Bannister, J. (2009). Movements of southern right whales (Eubalaena australis) between Australian and subantarctic New Zealand populations. Marine Mammal Science 25: 455-461

Segawa, T. And Kemper, C. (2015). Cetacean Strandings In South Australia (1881-2008). Australian Mammalogy 37:51-66

Rogers et al. (2013). Physical processes, biodiversity and ecology of the Great Australian Bight region: a literature review. CSIRO report.

Shaughnessy, P. D. (1999) The Action Plan for Australian Seals. Environment Australia, Canberra.

Shaughnessy P. D., Goldsworthy S. D., Mackay A. I. (2015) The long-nosed fur seal (Arctocephalus forsteri) in South Australia in 2013–14: abundance, status and trends. Australian Journal of Zoology 63, 101-110.

Smith. J., Jones. D., Travouillon. K., Kelly. N., Double. M. (2019). Project A7 – Monitoring Population Dynamics of ‘Western’ Right Whales off Southern Australia 2018-2021 – Final Report on activities for 2018.

Stamation, K., Watson, M., Moloney, P., Charlton, C., and Bannister, J. 2020. Population estimate and rate of increase of southern right whales Eubalaena australis in southeastern Australia. Endangered Species Research, Vol 41 pp 375-385.

Watson M, Westhorpe I, Bannister J, Hedley S, Harcourt R. (2015) Final report on the assessment of numbers and distribution of southern right whales in Southeast Australia. Report to the Australian Marine Mammal Centre.

Ward. R. R. McCauley, A.N. Gavrilov,·C.M. Charlton. (2019). Underwater Sound Sources and Ambient Noise in Fowlers Bay, South Australia, during the Austral Winter. Acoustics Australia


Download the full account of the Southern Australian Coastal and Shelf Region IMMA using the Fact Sheet button below:

To make a request to download the GIS Layer (shapefile) for the Southern Australian Coastal and Shelf Region IMMA please complete the following Contact Form:

    * Required fields

    Please read the User Licence Agreement and IMMA Layer Metadata Description