Australian Snubfin Dolphin
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Most information is obtained by comparing Australian Snubfin Dolphins to their close relatives who live in the same area: Irrawady Dolphin

Australian snubfin dolphins, Orcaella heinsohni, live in shallow coastal waters in northern Australia and possibly Papua New Guinea. In the Pacific Ocean off Townsville, about 200 individual snubfin dolphins were found. It is expected that the range of the species extends into Papua New Guinea, but that the majority live in Australian waters. They are not thought to be common and are being given a high conservation priority.

Unfortunately, because they live in these environments, they are susceptible to many human threats including accidental catch in shark and fishing nets as well as effects of coastal development.

Human threats on Irrawaddy dolphins in Southeast Asia are even more severe. Five Southeast Asian dolphin populations were recently classified as 'Critically Endangered' by the World Conservation Union. This means the total population is less than 50 individuals so there is a high chance of local extinction in the near future.

The maximum recorded length for males is 2.70 m and 2.30 m for females. The maximum weight is 133 kg. There appears to be some sexual dimorphism in Australian Snubfin Dolphins, with males growing larger than females (further studying needed). Schools of Australian Snubfin Dolphins vary in size from one to 15 animals, with an average of 5 individuals per school.

All cetaceans are protected within The Australian Whale Sanctuary under the EPBC Act. The Sanctuary includes all Commonwealth waters from the 3 nm state waters limit out to the boundary of the Exclusive Economic Zone (EEZ). The Australian Snubfin Dolphin is also subject to International Whaling Commission regulations and protected within the Indian Ocean Sanctuary and Southern Ocean Sanctuary.

Australian Snubfin Dolphins also occur in the Great Barrier Reef Marine Park. This species is regarded as a species of priority for management and research by the Great Barrier Reef Marine Park Authority.

Habitat
Within Australia, Australian Snubfin Dolphins have been recorded almost exclusively in coastal and estuarine waters. It is doubtful that they venture very far upstream in river systems, only occasional vagrants maybe.

Boat-based surveys along the east coast of Queensland indicate that Australian Snubfin Dolphins are primarily found in shallow waters less than 20 m deep, close to the coast, close to river and creek mouths and in the proximity of seagrass beds. Within Cleveland Bay, north-east Queensland, Australian Snubfin Dolphins tend to concentrate their activities in areas with these specific features. Within such areas, animals spend most of their time foraging and travelling, and to a lesser extent socialising. The predominance of foraging activities in these areas indicate that these areas represent important feeding habitats for these species.

The Australian Snubfin Dolphin has been found in the shallow coastal waters and estuaries along the Kimberley coast. Beagle and Pender Bays on the Dampier Peninsula and tidal creeks around Yampi Sound and between Kuri Bay and Cape Londonderry are important areas for Australian Snubfin Dolphins.

Life Cycle
The age at sexual maturity for Australian Snubfin Dolphins is unknown. The length at sexual maturity is about 2 m. Australian Snubfin Dolphins may reach an age of 28 years, and maximum lengths of 2.70 m in males and 2.30 m in females.

No causes of natural mortality are published, but individuals bearing shark bites have been observed off the east coast of Queensland. Large tiger sharks (Galeocerdo cuvier) and Bull Sharks (Carcharhinus leucas) are potential predators.

Australian Snubfin Dolphins have been observed socialising year round in Cleveland Bay, suggesting that Australian Snubfin Dolphins may mate year round. Australian Snubfin Dolphin calves are seen year round in Cleveland Bay, indicating that this species may not have a particular calving period.

Feeding
Australian Snubfin Dolphin prey includes fish of the families Engraulidae, Clupeidae, Chirocentridae, Anguillidae, Hemirhampidae, Leiognathidae, Apogonidae, Pomadasydae, Terapontidae and Sillaginidae. These fishes are typically associated with shallow coastal waters and estuaries in tropical regions.

Feeding may occur in a variety of habitats, from mangroves to sandy bottom estuaries and embayments, to rock and/or coral reefs. Feeding primarily occurs in shallow waters (less than 20 m) close to river mouths and creeks.

The taxonomic status of Orcaella in the northwest of Australia is unknown.

The following refers to the entire Orcaella genus only:
"Orcaella are declining throughout their range in Asia because of increased human activity including invasion of their habitat. In addition to habitat loss, overfishing including targeted catches, bycatch, and overfished Orcaella prey are impacting the abundance of these species. The Australian coast poses fewer threats for Orcaella, which makes conservation efforts even more important to protect this species and guide its management. Some research on the distribution, abundance and ecology of Orcaella has been conducted in Queensland in northeastern Australia, where human impact may be a problem. Little research has been conducted in northwest Australia on the Kimberley coast, which is thought to be part of Orcaella's habitat. This region is a remote coastal area that is beginning to become more heavily populated. This human presence may be resulting in habitat destruction and threats to Orcaella due to line trawling, tourism, recreational fishing, illegal fishing, petroleum exploration, and pearl farming. Studies here are urgently needed to ensure the longevity of Orcaella."

For more information: http://www.wwf.org.au/our_ work/saving_the_natural_world/ wildlife_and_habitats/ australian_priority_species/ coastal_dolphins/snubfin_ dolphins/

Videos:
http://www.youtube.com/watch?v=nm2lFwS6468 & http://www.youtube.com/watch?v=zakPeyXCUNk

Citations:
"Australian Snubfin Dolphins, Orcaella heinsohni ~ MarineBio.org." MarineBio Conservation Society. Web. Thursday, February 20, 2014. <http://marinebio.org/species.asp?id=1320>. Last update: 1/14/2013 2:22:00 PM

Department of the Environment (2014). Orcaella heinsohni in Species Profile and Threats Database, Department of the Environment, Canberra. Available from:http://www.environment.gov.au/sprat. Accessed Fri, 21 Feb 2014 04:19:20 +1100.

Hanzel, M. 2012. "Orcaella heinsohni" (On-line), Animal Diversity Web. Accessed February 21, 2014 at http://animaldiversity.ummz.umich.edu/accounts/Orcaella_heinsohni/

Paterson, RA and Van Dyck, SM 1998, Irrawaddy dolphins Orcaella brevirostris from southern Queensland. Memoirs of the Queensland Museum 42, 554.

Image Citations:
Thiele, Deborah. Sample of Kimberley Inshore Dolphin ID Card. Digital image. Kimberley Dolphin Monitoring. Roebuck Bay Working Group, 2009. Web. 14 Feb. 2014. <http://www.roebuckbay.org.au/volunteer-activities/dolphin-monitoring/>.