Biodiversity

Species Profile and Threats Database


For information to assist proponents in referral, environmental assessments and compliance issues, refer to the Policy Statements and Guidelines (where available), the Conservation Advice (where available) or the Listing Advice (where available).
 
In addition, proponents and land managers should refer to the Recovery Plan (where available) or the Conservation Advice (where available) for recovery, mitigation and conservation information.

EPBC Act Listing Status Cetacean as Orcaella brevirostris
Listed migratory - Bonn as Orcaella brevirostris
Adopted/Made Recovery Plans
Other EPBC Act Plans Threat abatement plan for the impacts of marine debris on vertebrate marine life (Department of the Environment, Water, Heritage and the Arts (DEWHA), 2009t) [Threat Abatement Plan].
 
Policy Statements and Guidelines Marine bioregional plan for the North Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012x) [Admin Guideline].
 
Marine bioregional plan for the North-west Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012y) [Admin Guideline].
 
Indo-Pacific humpback and Australian snubfin dolphins - A Vulnerability Assessment for the Great Barrier Reef (Great Barrier Reef Marine Park Authority (GBRMPA), 2011b) [Admin Guideline].
 
Seagrass - A Vulnerability Assessment for the Great Barrier Reef (Great Barrier Reef Marine Park Authority (GBRMPA), 2011k) [Admin Guideline].
 
Information Sheets Australian National Guidelines for Whale and Dolphin Watching (Department of the Environment and Heritage, 2005e) [Information Sheet].
 
Federal Register of
    Legislative Instruments
List of Migratory Species (13/07/2000) (Commonwealth of Australia, 2000b) [Legislative Instrument] as Orcaella brevirostris.
 
State Listing Status
QLD: Listed as Rare (Nature Conservation Act 1992 (Queensland): Near Threatened species: May 2014 list ) as Orcaella heinsohni
Non-statutory Listing Status
IUCN: Listed as Near Threatened (Global Status: IUCN Red List of Threatened Species: 2013.1 list)
WA: Listed as P4 (Priority Flora and Priority Fauna List (Western Australia): April 2014 list)
Scientific name Orcaella heinsohni [81322]
Family Delphinidae:Cetacea:Mammalia:Chordata:Animalia
Species author Beasley, Robertson and Arnold (2005)
Infraspecies author  
Reference Beasley, Kelly M. Robertson, and Peter Arnold (2005) Description of a new dolphin, the Australian Snubfin Dolphin Orcaella Heinsohni sp. n. (Cetacea, Delphinidae). Marine Mammal Science: Vol. 21, No. 3, pp. 365-400.
Other names Orcaella brevirostris [45]
Distribution map Species Distribution Map

This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.

Illustrations Google Images

Scientific name: Orcaella heinsohni (previously O. brevirostris)

Common name: Australian Snubfin Dolphin

Other names: Formerly known as the Irrawaddy Dolphin

The Irrawaddy Dolphin was described by Gray (1866) as a redescription of the dolphin described by Owen the previous year. Historically, only one species is recognised, Orcaella brevirostris (Rice 1998). However, the phylogenetic status of the species has been uncertain, with both molecular and morphologic evidence suggesting that the closest affinities lie with the delphinids, rather than among the externally similar Monodontidae (Arnold & Heinsohn 1996; Grétarsdóttir & Árnason 1992; LeDuc 1999; Lint et al. 1990; see also Rice 1998 for discussion). Recent research has shown that the Australia/New Guinea population of Irrawaddy Dolphin differs from the Asian populations genetically, morphologically and in their habitat preferences (Beasley et al. 2002) prompting a new species, the Australian Snubfin Dolphin, Orcaella heinsohni, to be suggested (Beasley et al. 2005). The new scientific name is tentatively used by Ross (2006), with the recommendation that additional morphological and genetic work be undertaken before being accepted formally. A similar approach has been taken here.

Australian Snubfin Dolphins are characterised by a broadly rounded head that is extremely mobile and usually has a visible neck crease (Beasley et al. 2005). There is no sign of a beak and the mouth line is straight. The teeth in Orcaella are peg-like and number less than 20 on each side of the jaws (Martin 1990). In the reverse situation to most dolphins, the u-shaped blowhole of Orcaella is open to the front (Leatherwood & Reeves 1983). A distinctive feature of Australian Snubfin Dolphins appears to be a lack of a dorsal groove between the snout and the dorsal fin (Beasley et al. 2005). The dorsal fin of the Australian Snubfin Dolphin is small and situated in the latter half of the body (Beasley et al. 2005), while the flippers are broad, paddle-like and highly mobile. The colour pattern for Australian Snubfin Dolphins is characteristic, with a subtle three-tone consisting of a dark cape, white abdomen and intermediate light grey to brownish grey side (Arnold & Heinsohn 1996; Beasley et al. 2005).

Australian Snubfin Dolphins are longer than the closely related Irrawaddy Dolphin (O. brevirostris); the maximum recorded length for males is 2.70 m and 2.30 m for females (Beasley et al. 2005). The maximum weight is 133 kg (Arnold & Heinsohn 1996). There appears to be some sexual dimorphism in Australian Snubfin Dolphins, with males growing larger than females, but further specimens are required for examination before this can be verified (Beasley et al. 2005). Schools of Australian Snubfin Dolphins vary in size from one to 15 animals, with an average of 5 individuals per school (Parra 2005).

Stranding and museum specimen records indicate that Australian Snubfin Dolphins occur only in waters off the northern half of Australia, from approximately Broome (17° 57´ S) on the west coast to the Brisbane River (27° 32´ S) on the east coast (Parra et al. 2002a). Aerial and boat-based surveys indicate that Australian Snubfin Dolphins occur mostly in protected shallow waters close to the coast, and close to river and creek mouths (Parra 2006; Parra & Corkeron 2001; Parra et al. 2002a).

The large area of shallow water on the northern Sahul Shelf, plus records of Australian Snubfin Dolphins out to 23 km offshore, suggests that even though the known distribution is limited, its occurrence probably exceeds 20 000 km² (Peddemors & Harcourt 2006, pers. comm.). There are no data to estimate any past or potential future declines of occurrence of Snubfin Dolphins in Australia.

The area of occupancy of Australian Snubfin Dolphins cannot be calculated due to the paucity of sighting records for a large proportion of the range. However, the area of occupancy is likely to be greater than 2000 km² (Peddemors & Harcourt 2006, pers. comm.). There are no data to estimate any past or potential future declines in the area of occupancy for Snubfin Dolphins in Australia, however incidental catches in gillnets (albeit at unknown levels), plus habitat degradation, may lead to a reduction of area of occupancy over the next three generations for Australian Snubfin Dolphins.

All available data on the distribution and habitat preferences of Australian Snubfin Dolphins indicate that they mainly occur in one location: shallow coastal and estuarine waters of Queensland, Northern Territory and north Western Australia (Beasley et al. 2002). The population in Australian waters is thought to be continuous with Papua New Guinea, but separate (putatively a different species) from populations in Asia (Ross 2006).

There appears to be 'hotspots' of higher Australian Snubfin Dolphin densities along the Queensland coast (Parra et al. 2002a) and preliminary data suggest that they occur in small, localized populations (Stacey & Arnold 1999). However, available data is currently too limited to examine the likelihood for fragmentation.

Only a single record for the Australian Snubfin Dolphin exists outside Australia, and comes from Daru, Papua New Guinea (Beasley et al. 2002). Most recorded sightings come from protected and shallow coastal waters, especially in close vicinity to river mouths, which implies that their expected range is the northern Sahul Shelf including the coastal waters of northern Australia and Papua New Guinea (Beasley et al. 2005).

No global population size is known. In Australian waters, population sizes are estimated to be low, thus making population changes extremely difficult to detect within the space of a few years unless changes are severe (e.g. >20% p.a) (Parra 2006). If populations elsewhere throughout their range (Papua New Guinea) are also small, trends will likewise be difficult to detect.

The limited range outside of Australia for this species suggests that there could be significant threat to the security of Australian Snubfin Dolphins living beyond Australian territorial waters. This threat would primarily consist of incidental capture in gillnets. Organochlorines, especially DDTs, may also be compromising the health of Australian Snubfin Dolphin populations, while habitat destruction is likely to be a substantial, albeit unquantified, threat to the species throughout its range.

The large expanses of shallow water (<50 m depth) on the Sahul Shelf suggests that it may be possible for Australian Snubfin Dolphins to range between northern Australia and the Sahul Islands of eastern Indonesia and Papua New Guinea. Considering the small range of distribution for this species, it is very possible that threats operating outside Australian waters may affect the Australian population.

This species is not well surveyed across its range. The knowledge about the distribution of Australian Snubfin Dolphins is primarily from stranding records, and opportunistic sightings during aerial surveys for Dugongs (Dugong dugon) (Parra et al. 2002a). Systematic boat-based surveys have been conducted in Cleveland Bay, Hinchinbrook, Princess Charlotte Bay, Ninian Bay and Bathurts Bay, north-east Queensland (Parra 2005; Parra 2006). Based on the available data the distribution of Australian Snubfin Dolphins covers the coastal waters of Queensland, Northern Territory and north-western Australia.

The only attempt to estimate abundance of Australian Snubfin Dolphins in Australian waters was through an aerial survey in the western Gulf of Carpentaria that estimated a population of about 1000 individuals (Freeland & Bayliss 1989). However, this estimate has been questioned due to the known difficulty of identifying dolphin species in turbid waters from the air, particularly since Australian Snubfin Dolphins are inconspicuous, have low surfacing profiles and are elusive (Parra et al. 2002a).

The only reliable local estimate of population size of Australian Snubfin Dolphins is for Cleveland Bay, north-east Queensland, where a population of less than a 100 individuals inhabits this area (Parra et al. 2002a). Based on the low numbers of Australian Snubfin Dolphins sighted during aerial and boat based surveys of the east coast of Queensland (Parra et al. 2002a; Parra 2006) the population at a regional level (Queensland) is likely to be in the thousands rather than tens of thousands (Parra 2006). Considering the length of coastline and area of suitable shallow habitat and the apparent occurrence of Snubfin Dolphins in small localised groups, it is likely that mature Australian Snubfin Dolphins do not number more than 10 000 individuals (Peddemors & Harcourt 2006, pers. comm.).

At present the distribution of the Australian Snubfin Dolphin is considered to be contiguous with occasional preferred areas exhibiting apparent higher Snubfin Dolphin densities. However, the lack of abundance and distribution data does not allow definitive assessment.

It is likely that the population has been reduced off Queensland and the Gulf of Carpentaria, primarily related to continued incidental capture in gillnets, including shark nets, and continued habitat degradation. However, the number of Australian Snubfin Dolphins taken in gillnets and shark nets at a national level is unknown (Parra et al. 2002a). Additionally the small population sizes estimated for Australian Snubfin Dolphins makes detection of population trends extremely difficult (Parra et al. 2002a). Future decreases in the Australian Snubfin Dolphin population size is likely to continue due to degradation of the species' habitat, plus some incidental mortality in gillnets (Parra 2006). Other anthropogenic activities may also impact negatively on Australian Snubnose Dolphins, including increased boat traffic, pollution of the coastal habitat, and overfishing of potential prey stocks (Parra et al. 2002a).

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) (i.e. out to 200 nm and further in some places). The Australian Snubfin Dolphin is also subject to International Whaling Commission regulations and protected within the Indian Ocean Sanctuary and Southern Ocean Sanctuary (Ross 2006).

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 (GBRMPA 2000; Parra 2006).

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, although occasional vagrants may venture upstream (Parra et al. 2002a).


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 (Parra 2006; Parra et al. 2002a). 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 (Parra 2006).

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 (DEWHA 2008b).

Australian Snubfin Dolphins share similar habitat preferences with Indo-Pacific Humpback Dolphins, with these two species potentially sympatric (occurring in the same areas) throughout most of their Australian range (Parra 2006).

The age at sexual maturity for Australian Snubfin Dolphins is unknown. The length at sexual maturity is about 2 m (Ross 2006). 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 (based on 37 Australian dolphins: Arnold, pers. comm. in Ross 2006). No causes of natural mortality are published, but individuals bearing shark bites have been observed off the east coast of Queensland (Parra, pers. obs. in Ross 2006). Large tiger sharks (Galeocerdo cuvier) and Bull Sharks (Carcharhinus leucas) are potential predators.

Limited data is available for the Australian Snubfin Dolphin, resulting in reproductive parameters being estimated from the closely related Irrawaddy Dolphin. The Irrawaddy Dolphin's mating season is from March to June (at 11°–12° N), and April to June (at 0°–1° S) (Ross 2006). However, Australian Snubfin Dolphins have been observed socialising year round in Cleveland Bay, suggesting that Australian Snubfin Dolphins may mate year round. Gestation for Irrawaddy Dolphins lasts 14 months (captive animal) and calves are born in August or September. It is thought that this calving period may either be extended at low latitudes, or that there may be significant geographical variation, as newborns have been recorded from near Calcutta in June, in Laos from April to May, and in the Townsville region in August (Ross 2006). Australian Snubfin Dolphin calves are seen year round in Cleveland Bay, indicating that this species may not have a particular calving period (Parra 2006).

The weight and length at birth of a captive Irrawaddy Dolphin was 12.3 kg and 0.96 m, respectively, while weaning occurred at two years old (Ross 2006). No calving areas are known in Australian waters, but a near-term foetus and a neonate are recorded from Townsville (Bannister et al. 1996).

Australian Snubfin Dolphin prey includes fish of the families Engraulidae, Clupeidae, Chirocentridae, Anguillidae, Hemirhampidae, Leiognathidae, Apogonidae, Pomadasydae, Terapontidae and Sillaginidae (Heinsohn 1979; Marsh et al. 1989). These fishes are typically associated with shallow coastal waters and estuaries in tropical regions (Parra et al. 2002a).

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 information available for Cleveland Bay indicates that Australian Snubfin Dolphins are not permanent residents in the Bay, but use the area regularly from year to year following a model of emigration and re-immigration. Individuals spend periods of days to a month or more in coastal waters of Cleveland Bay before leaving, and periods of over a month outside the study area before re-entering the Bay again.

Home ranges and/or territories for this species appear to be large, as many of the identified individuals spent less than 30 days within the 310 km² Cleveland Bay study area (Parra 2006).

Distinctiveness
Once detected, the Australian Snubfin Dolphin is easy to identify by their distinctive bulbous head with no beak and the presence of a very small dorsal fin.

Detectability
Australian Snubfin Dolphins are, however, difficult to detect due to their inconspicuous behaviour, unpredictable surfacing patterns, low surfacing profile, their tendency to live in turbid coastal waters, and their occurrence in relatively small groups. Typical surfacing characteristics when animals are travelling are short dives of 30–60 seconds, increasing to two to three minutes when animals are foraging.

Recommended methods
Cetacean surveys are constrained by several important factors including weather (e.g. sea state and light conditions), area to be covered, aim of the survey (abundance estimate versus ecological studies), the activities of the animals themselves (e.g. travelling, resting, surface versus deep feeding), and the type of craft used for the survey. For species such as the Snubfin Dolphin, the water clarity and the inconspicuous behaviour of the animals are major constraints on the suitability of survey techniques.

Surveys for Australian Snubfin Dolphins have included land-based observations, boat-based line transects, aerial surveys, and photo-identification (Freeland & Bayliss 1989; Parra & Corkeron 2001; Parra et al. 2002a; Parra 2006). Methods used for the respective surveys have been described by their authors.

The past and current threats to Australian Snubfin Dolphins include habitat destruction and degradation; incidental capture in gillnets; traditional hunting by Indigenous Australian communities; and live capture for oceanariums (Bannister et al. 1996). In addition, competition with fisheries for prey species is also expected to have become a threat in recent years as fishers turned their attention to estuarine-associated fish that have previously not been targeted.

Habitat destruction and degradation
Habitat degradation and loss is primarily a concern along the Queensland coast with its high level of construction, dredging, mining, land reclamation, resource extraction, agricultural development, commerce, tourism and recreational activities that are currently present and are likely to continue.

In the Northern Territory, the development of a liquefied natural gas plant in waters at Wickham Point, Darwin, and dredging for the port of the McArthur River mine, western Gulf of Carpentaria, have also been highlighted as potential impacts on the species.

Off the Kimberley, Western Australia, the development of infrastructure mostly associated with the petroleum industry and iron ore activities, and seismic surveys and petroleum explorations are of concern and are suspected to have an impact at the local level at all affected sites. This threat to Australian Snubfin Dolphins is considered likely to continue into the future, with the potential to increase its impact as habitat degradation and loss increase with increased human population requirements (Bannister et al. 1996; Parra et al. 2002a).

Incidental capture in nets
Incidental captures have occurred in nets set across creeks, rivers and shallow estuaries for barramundi (Lates calcarifer) and Threadfin Salmon (Polynemus sheridani and Eleutheronema tatradactylum) (DEW 2007a; Hale 1997), and in shark nets set for bather protection (Gribble et al. 1998; Paterson 1990). Captures have occurred primarily in the northern part of the species' range, but the magnitude is unknown. Between 1967 and 1987, 520 dolphins were caught in mesh along the Queensland coast, with the Australian Snubfin Dolphin being the most common species caught in nets north of Mackay. From 1993 to 2003, eight Australian Snubfin Dolphins were caught in nets, of which five died (DEW 2007a). Regulations to reduce incidental non-target mortalities, such as net attendance rules and gear modifications, have been introduced but enforcement is lacking in remote areas (Hale 1997). The impact on Australian Snubfin Dolphins is expected to reduce as mitigation measures become more common and better policed.

Shark nets set for the protection of swimmers capture Australian Snubfin Dolphins, and kill an estimated 1.3 individuals per annum along the Queensland coast (Gribble et al. 1998). Most captures in shark nets occur in the Townsville area, suggesting there may be potential for local stock depletion (Parra et al. 2002a). Although trawl nets and driftnets have not reported incidental bycatch, they may occasionally capture this species.

Competition with fisheries
Fishing of prey species is an unquantified impact as no quantitative studies on the feeding habits of Australian Snubfin Dolphins have been made. However, based on the distribution and habitat preferences of this dolphin species, plus studies of stomach contents (Heinsohn 1979; Marsh et al. 1989), it appears that this species feeds mainly on estuarine-associated fish species. These prey species constitute a component of the shrimp trawl fishery bycatch, plus are targeted in some areas by estuarine fishers (e.g. barramundi and threadfin salmon). This potential anthropogenic impact can be expected throughout the Australian range of this species. Additional threats may come through targeted fishing of these potential Australian Snubfin Dolphin prey-fish. This is expected to become an increasing threat as fishers turn their attention to estuarine-associated fish that have previously not been targeted. This suspected threat may increase in future years as fishers target historically less desirable fish due to collapse of preferred fish stocks.

Pollution of habitat
The northern and north-western coastlines are relatively unpopulated compared to other areas within the Australian Snubfin Dolphin's range. However, pollutants still enter coastal and estuarine waters along Australia's northern coastline, and can be of many types (e.g. heavy metals, pesticides, herbicides, nutrients and sediments) and from many different sources (e.g. industrial and sewage discharges, catchment runoff and groundwater infiltration) (Cosser 1997). The concentration and rapid growth, especially along the urban coast of Queensland has placed increased pressure on coastal resources. Although the ecological significance of existing contaminants within the range of Australian Snubfin Dolphins is not known, recent studies on contaminant levels and water quality along the urban Queensland coastline indicate that there is a significant risk that some areas might be damaged in the future. Organohalogen pollutant levels in marine mammals from north-east Queensland were higher than expected, and may therefore affect this species. Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) levels off Queensland were also found to be high (Gaus et al. 2001), potentially threatening species such as Australian Snubfin Dolphins that prefer sheltered shallow waters. The adverse effects of complex mixtures of organohalogen compounds and PCDD/Fs on marine mammal health are not fully understood, but their toxic properties and high concentration in Bottlenose Dolphins and Dugongs along the Queensland coast suggests they may also be a threat to Australian Snubfin Dolphins in Australia. This threat is likely to escalate as industrial and agricultural activities along the coastline increase (Bannister et al. 1996).

The Australian Snubfin Dolphin depends on coastal and riverine habitats that may be affected by developments and pollution. Higher levels of polychlorinated biphenyls (PCBs) have been found in dolphins from the Gold Coast than anywhere else in Australia. High levels of PCBs have been linked to severely impaired reproductive capacity in dolphins. Some dolphins are thought to feed regularly around sewage outlets and port facilities and could be vulnerable to contamination from poor water quality. Some studies have found significant levels of mercury in the respiratory tracts of dolphins, raising the possibility that air quality adjacent to major centres may affect dolphins (DEW 2007a)

Interaction with vessels
The coastal near-shore distribution of Australian Snubfin Dolphins leads to the high probability of interactions with vessels. Boat traffic in densely populated areas of the Queensland coast has increased dramatically in the past decade, with predictions that this will increase even further in future years. Australian Snubfin Dolphins can be expected to exhibit vessel avoidance behaviour, potentially negatively affecting their extent of occupancy and life history, as per other nearshore dolphins (Bedjer et al. 2006). Additionally, the frequencies of whistles produced by Australian Snubfin Dolphins are likely to fall within the range often emanating from boat traffic, suggesting that noise pollution may a problem for this species.

Pathogens
Marine mammals are very susceptible to pathogen-induced mass mortalities (Bannister et al. 1996), suggesting that an epizootic event could threaten a species like the Australian Snubfin Dolphin with its apparently small population size and restricted coastal range. Recent studies have shown that three Humpback Dolphins recovered in the Townsville region between 2000 and 2001 were infected with Toxoplasmosis gondii (Bowater et al. 2003), a terrestrial parasite that can be fatal or have deleterious effects on the health of marine mammals (e.g., infection with T. gondii is one of the leading causes of mortality of southern sea otters along the California coast: Kreuder et al. 2003). Given their small population size and the fact that they occupy similar habitats to Humpback Dolphins, the incidence of this pathogen is of serious concern for the conservation of Snubfin Dolphins (Parra 2006).

Slow reproductive rate
The calving interval of Australian Snubfin Dolphins is unknown, however, as per most Delphinidae, it is expected to be approximately one calf born per two to three years. This low reproductive rate could result in a slow population recovery from any threatening processes.

Bannister and colleagues (1996) and Ross (2006) recommend the following actions be taken to better understand the threats to Australian Snubfin Dolphins:

  • Determine the distribution and monitor abundance of Australian Snubfin Dolphins in Australian waters to assess the possible impact of threats, particularly the effect of direct and indirect fishing activities. This should be done via boat-based surveys and line transect techniques, particularly in northern waters.
  • Obtain information on Australian Snubfin Dolphin diet to determine their trophic level and assess any possible impact of the fishing industry on dolphin food resources.
  • Determine the taxonomic relationships within and outside the Sahul Shelf region to assess the likely impact of threats on possible individual populations of Australian Snubfin Dolphins.
  • Obtain basic biological information (including diet, pollutant levels, and genetic samples) from incidentally-caught and stranded Australian Snubfin Dolphin specimens, especially from the Arafura and Timor Seas. This should include ensuring specimens are made available to appropriate scientific museums to enable collection of life history data and tissue samples for genetic analysis.
  • Develop an education program and information material about Australian Snubfin Dolphins, and distribute to the general public.
  • Develop a community sighting program throughout their range to monitor distribution.

Past projects initiated to address these threats include:

  • a study of incidental catch in Arafura and Timor seas, 1981–1985, by the Australian National Parks and Wildlife Service
  • surveys of the Queensland coast by researchers at the James Cook University.

Current projects include:

  • Spatial modelling of habitat suitability for snubfin dolphins within the Great Barrier Reef Marine Park by the University of Queensland.
  • Conservation genetics of Snubfin Dolphins in Australian waters by the University of Queensland.
  • Boat-based surveys off Broome Western Australia.
  • Photo-identification surveys off the south-east coast of Queensland by the Southern Cross University.

  • Since these recommendations were made the impact of the gillnet fishery on this species in the Arafura and Timor Seas is likely to have eased, with available information indicating that such activities have all but ceased in these regions (Ross 2006). Additionally, there is now a requirement to report all incidental catches made within the Australian EEZ (Bannister et al. 1996).

    Marine bioregional plans have been developed for four of Australia's marine regions - South-west, North-west, North and Temperate East. Marine Bioregional Plans will help improve the way decisions are made under the EPBC Act, particularly in relation to the protection of marine biodiversity and the sustainable use of our oceans and their resources by our marine-based industries. Marine Bioregional Plans improve our understanding of Australia's oceans by presenting a consolidated picture of the biophysical characteristics and diversity of marine life. They describe the marine environment and conservation values of each marine region, set out broad biodiversity objectives, identify regional priorities and outline strategies and actions to address these priorities. Click here for more information about marine bioregional plans.

    The Australian snubfin dolphin has been identified as a conservation value in the North (DSEWPaC 2012x) and North-west (DSEWPaC 2012y) marine regions. See Schedule 2 of the North-west Marine Bioregional Plan (DSEWPaC 2012y) and the North Marine Bioregional Plan (DSEWPaC 2012x) for regional advice. Maps of Biologically Important Areas have also been developed for Australian snubfin in the North-west (DSEWPaC 2012y) and North (DSEWPaC 2012x) marine regions and may provide additional relevant information. Go to the conservation values atlas to view the location of these Biologically Important Areas. The "species group report card - cetaceans" for the North-west (DSEWPaC 2012y) and North (DSEWPaC 2012x) marine regions provide additional information.

    The following table lists known and perceived threats to this species. Threats are based on the International Union for Conservation of Nature and Natural Resources (IUCN) threat classification version 1.1.

    Threat Class Threatening Species References
    Biological Resource Use:Fishing and Harvesting Aquatic Resources:Commercial harvest Orcaella brevirostris in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006ry) [Internet].
    Biological Resource Use:Fishing and Harvesting Aquatic Resources:Illegal fishing practices and entanglement in set nets Orcaella brevirostris in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006ry) [Internet].
    Biological Resource Use:Fishing and Harvesting Aquatic Resources:Indigenous hunting and harvesting Orcaella brevirostris in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006ry) [Internet].
    Biological Resource Use:Fishing and Harvesting Aquatic Resources:Overfishing, competition with fishing operations and overfishing of prey fishing Orcaella brevirostris in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006ry) [Internet].
    Invasive and Other Problematic Species and Genes:Invasive and Other Problematic Species and Genes:Presence of pathogens and resulting disease Orcaella brevirostris in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006ry) [Internet].
    Natural System Modifications:Natural System Modifications:Indirect and direct habitat loss due to human activities Orcaella brevirostris in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006ry) [Internet].
    Pollution:Excess Energy:noise Orcaella brevirostris in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006ry) [Internet].
    Pollution:Pollution:Pollution due to oil spills and other chemical pollutants Orcaella brevirostris in Species Profile and Threats (SPRAT) database (Department of the Environment and Heritage, 2006ry) [Internet].

    Arnold, P. & G. Heinsohn (1996). Phylogenetic status of the Irrawaddy dolphin Orcaella brevirostris (Owen in Gray): a cladistic analysis. Memoirs of the Queensland Museum. 39:141-204.

    Bannister, J.L., C.M. Kemper & R.M. Warneke (1996). The Action Plan for Australian Cetaceans. [Online]. Canberra: Australian Nature Conservation Agency. Available from: http://www.environment.gov.au/resource/action-plan-australian-cetaceans.

    Beasley I., K.M. Robertson & P. Arnold (2005). Description of a new dolphin: The Australian snubfin dolphin Orcaella heinsohni sp.n. (Cetacea, Delphinidae). Marine Mammal Science. 21(3):365-400.

    Beasley, I.L., P.W. Arnold & G.E. Heinsohn (2002). Geographical variation in skull morphology of the Irrawaddy dolphin, Orcaella brevirostris. Raffles Bulletin of Zoology. 10:15-24.

    Bedjer, L., A. Samuels, H. Whitehead, N. Gales, J. Mann, R. Conner, M. Heithaus, J. Watson-Capps, C. Flaherty, & M. Krützen (2006). Decline in relative abundance of bottlenose dolphins exposed to long-term disturbance. Conservation Biology. 20 (6).

    Bowater, R.O., J. Norton, S. Johnson, B. Hill, P. O'Donoghue & and H. Prior (2003). Toxoplasmosis in Indo-Pacific humpbacked dolphins (Sousa chinensis), from Queensland. Australian Veterinary Journal. 81:627-632.

    Cosser, P., ed. (1997). Nutrients in Marine and Estuarine Environments. Australia: State of the Environment Technical Paper Series (Estuaries and the Sea). Canberra, Department of the Environment.

    Department of the Environment and Heritage (2005e). Australian National Guidelines for Whale and Dolphin Watching. [Online]. Available from: http://www.environment.gov.au/resource/australian-national-guidelines-whale-and-dolphin-watching-2005.

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    Citation: 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 Tue, 15 Jul 2014 00:07:20 +1000.