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|
|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-west Marine Region (Department of Sustainability, Environment, Water, Population and Communities (DSEWPaC), 2012y) [Admin Guideline].
Australian National Guidelines for Whale and Dolphin Watching (Department of the Environment and Heritage, 2005e) [Information Sheet].
|Non-statutory Listing Status||
|Scientific name||Lagenodelphis hosei |
This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.
The current conservation status of Fraser's Dolphin, Lagenodelphis hosei, under Australian legislation and international conventions, is as follows:
National: Listed as Cetacean under the Environment Protection and Biodiversity Conservation Act 1999.
The SE Asian population of Lagenodelphis hosei is also listed as Migratory under the Environment Protection and Biodiversity Conservation Act 1999.
Scientific name: Lagenodelphis hosei
Common name: Fraser's Dolphin
Other names: Sarawak Dolphin
Fraser's Dolphin was described relatively recently (1956) from a single skull specimen collected in Borneo (Perrin et al. 1973). The affinities of this species to other delphinids (dolphins) is uncertain. Morphologically, the skull most closely resembles that of the Common Dolphin, Delphinus delphis. Genetic analysis of the DNA (mitochondrial cytochrome b) indicates a relationship with the genera Stenella, Tursiops, Delphinus and Sousa (LeDuc et al. 1999).
Fraser's Dolphin is a stocky dolphin with a short beak and thick tail stock. Flippers, dorsal fin and tail flukes are all relatively small and pointed. The body is bluish grey on the back and white on the belly, with longitudinal stripes along the flanks. A cream band begins above and forward of the eye, extending along the flank until it becomes indistinct above the anus. A parallel black stripe begins around the eye (below the cream band) and also extends to the anus.
Males and females are known to reach maximum lengths of 2.7 m and 2.6 m respectively (Louella & Dolar 2002). Adult males (more than ten years old) are significantly larger than females, and may weigh up to 210 kg (Louella & Dolar 2002).
Fraser's Dolphins may school into groups consisting of less than 10 to about 1000 individuals. This species is considered highly gregarious, with the school bond apparently tight. They have been observed with Striped and Spotted Dolphins, False Killer Whales and Sperm Whales and often with Melon-headed Whales (Peddemors & Harcourt 2006, pers. comm.).
In Australia, Fraser's Dolphin is found in oceanic waters north of 30° S and deeper than 1000 m. Strandings have been recorded in Western Australia (2), Queensland (1), northern NSW (3) and Victoria (1 in Corio Bay at 38° S) (Bannister et al. 1996).
The current extent of occurrence of Fraser's Dolphin is estimated to be greater than 20 000 km² (based on the Australian Exclusive Economic Zone (EEZ) (200 nm, north of 30º S and deeper than 1000 m) (Peddemors & Harcourt 2006, pers. comm.). Increasing ocean temperatures predicted by climate change scenarios could potentially increase the extent of occurrence of Fraser's Dolphin, with warmer water extending southwards along both coasts.
The current area of occupancy of Fraser's Dolphin is estimated to be greater than 2000 km² (Peddemors & Harcourt 2006, pers. comm.).
Fraser's Dolphin is thought to occur across a single continuous location as there are no known unsurpassable fixed pelagic boundaries, and deep water does not appear to be a barrier to this species (Peddemors & Harcourt 2006, pers. comm.).
The first live Fraser's Dolphins were recorded in 1971, when they were found in three areas:
- the eastern tropical Pacific
- off the coast of NSW, Australia
- off Durban, KwaZulu-Natal South Africa.
Fraser's Dolphin is now considered to have a pan-tropical distribution, and is expected to occur between 30° N and 30° S in all three major ocean basins. Recorded sightings outside of these latitudes may represent vagrants influenced by temporary oceanographic events (Louella & Dolar 2002).
Fraser's Dolphin typically occurs in pelagic or oceanic habitat, and may be found along the outer continental shelf or slope, in deep oceanic waters (Mörzer Bruyns 1971), or nearshore in areas where deep water approaches the coast, such as the Philippines, Indonesia and the Lesser Antilles (Louella & Dolar 2002). In southern Africa, Fraser's Dolphins are recorded in strong association with the sub-tropical component of the Agulhas Current. Off Australia, they are found year-round off the shelf edge in waters deeper than 500 m. The distribution of Fraser's Dolphin in the south-western Indian Ocean may be localised (Bannister et al. 1996).
Fraser's Dolphin is not considered to be rare. The population in the eastern tropical Pacific has been estimated at a maximum of 289 000 animals. No estimates are available for other areas in its range (Bannister et al. 1996).
Fraser's Dolphin has not been well surveyed in Australia. The distribution of this species has primarily been assumed from beach-cast animals. However, this method is believed to result in reliable distributional information for the species (Peddemores & Harcourt 2006, pers. comm.).
While the size of the Australian population is unknown, the species is potentially abundant in Australian waters, and is considered likely to exceed 10 000 mature individuals (Peddemores & Harcourt 2006, pers. comm.). Seven strandings have been recorded in Australia (Bannister et al. 1996; Ross 2006).
Based on information from elsewhere in their range, it is thought that Fraser's Dolphin is likely to occur in one population within Australian waters.
The population of Fraser's Dolphins can be assumed to have been reduced due to human-induced mortalities such as capture in fishing nets. However, as no detailed population assessments have been conducted it is not possible to estimate the extent of decline. Ongoing incidental captures are the most likely cause of potential future population declines (Bannister et al. 1996).
Although some seasonal variation in population numbers have been recorded elsewhere (Findlay et al. 1992; Louella & Dolar 2002) no extreme population fluctuations are known for Fraser's Dolphin within Australian waters.
The generation length in Fraser's Dolphin is considered to be around 15 years, based on an age at sexual maturity of seven years and a likely calving interval of 3 years (as per other small cetaceans) (Ross 2006).
Attempts have been made to establish captive animals in the past. However, these are unlikely to be continued as Fraser's Dolphin becomes very distressed in shallow water, possibly because it is unaccustomed to this environment (Ross 2006).
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 EEZ (i.e. out to 200 nm and further in some places).
Fraser's Dolphin inhabits pelagic and oceanic habitats in subtropical, tropical and, occasionally, temperate waters. All sightings off South Africa were over depths exceeding 1000 m and associated with the warm Agulhas Current. This species is often found in waters characterised by a stable, shallow mixed layer and thermocline ridging, as well as upwelling areas (Ross 2006).
Male Fraser's Dolphins reach sexual maturity between seven to ten years and at 220230 cm, while females mature earlier at five to eight years and 210220 cm (Louella & Dola 2002). Life expectancy exceeds 16 years, and an individual captured in Japan was estimated to be 17.5 years old (Louella & Dola 2002). Most biological information is based on limited, non-Australian information (Ross 2006).
The limited data available for Fraser's Dolphin suggest that calving and conception may occur during the summer months. Calves are born about 1 m in length after an inferred gestation period of 1012 months. There are no known calving areas in Australian waters (Bannister et al. 1996).
Fraser's Dolphin feeds on mesopelagic fish, squid and crustaceans. Fish appear to form the most important component (Robison & Craddock 1983), even in areas apparently out of its normal range (van Bree et al. 1986). Fraser's Dolphin may selectively feed on larger prey (Bannister et al. 1996; Ross 1984).
Some recorded prey are deep-sea or benthic species, suggesting that Fraser's Dolphin either feeds at depth (250500 m) or when prey surface at night. Vertical or daily movement could increase the susceptibility to incidental capture in high-seas driftnets.
The unique body shape of Fraser's Dolphin should rule out confusion with other dolphins. In particular, the stocky body and extremely small appendages make this species distinctive. The short dorsal fin is triangular or slightly falcate, and the beak is a very stubby, but well defined. At a distance, Fraser's Dolphin may be confused with the Striped Dolphin as both species exhibit an eye-to-anus stripe.
Schools of Fraser's Dolphins tend to be large, often consisting of between hundreds and thousands of individuals. This species may also occur in mixed schools with other cetaceans, particularly Melon-headed Whales (eastern tropical Pacific, Philippines and Gulf of Mexico), Risso's or Spinner Dolphins (Philippines). This schooling behaviour makes them reasonably easy to detect.
The swimming style of Fraser's Dolphin is aggressive, often creating a spray as they charge to the surface to breathe. They are known to leap clear of the water, but are less acrobatic than many other pelagic dolphins.
The swimming style of Fraser's Dolphin is aggressive, often creating a spray as they charge to the surface to breathe. They are known to leap clear of the water, but are less acrobatic than many other pelagic dolphins.
Recommended Survey 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 or deep feeding), and the type of craft used for the survey.
Surveys for pelagic dolphins have primarily been boat-based transects, although some aerial surveys have been conducted in the eastern tropical Pacific. Almost no dedicated cetacean surveys have been conducted in Australia's northern waters. Surveys associated with petro-chemical exploration could potentially be used as platforms of survey opportunity (Bannister et al. 1996).
It has been recommended that basic biological information be obtained from incidentally-caught animals from fishing vessels: one biologist on fishing vessels for one year is recommended. A minimum requirement for sighting survey programs operating from existing cruises is two observers on two vessels for one year. It may also be possible to link observation information with incidental catch biology as outlined above (Peddemores 2006, pers. comm.).
This species was subject to sporadic catches by whalers (for meat) in the 19th century, but has never been the target of a directed fishery. However, harpoon fisheries in Indonesia, Sri Lanka, Taiwan and Japan, along with incidental capture in gill-net fisheries in the Philippines (second most frequently caught species) and Sri Lanka, and purse-seine deaths in the eastern tropical Pacific, continue to threaten this species (Bannister et al. 1996; Ross 2006). Fraser's Dolphin is also at risk of entanglement in driftnets set outside Australian Territorial Waters and in lost or discarded netting. Incidental and illegal captures within Australian waters off the northern coast may also be a threat.
Pollution, including increasing amounts of plastic debris at sea, oil spills and dumping of industrial wastes into waterways and seas, are leading to bio-accumulation of toxic substances in body tissues of marine species (Bannister et al. 1996) and may therefore threaten populations of Fraser's Dolphin.
Disease, such as lung lesions caused by nematodes (McColl & Obendorf 1982), severe bronchopneumonia associated with lungworm, and trematode ova found in blowholes may also threaten survival.
Schooling marine mammals, such as Fraser's Dolphin, are very susceptible to pathogen-induced mass mortalities, including epizootics (Bannister et al. 1996) because of their gregarious, highly social nature.
The low reproductive rate (one offspring every 23 years) of Fraser's Dolphin means that population recovery is a slow process (Ross 2006).
Bannister and colleagues (1996) recommend the following measures to be taken to better understand the threats to Fraser's Dolphin:
- Determine the distribution and abundance of Fraser's Dolphin in Australian waters to better assess the possible impact of threats, particularly the effect of direct and indirect fishing activities.
- Obtain information on the diet of Fraser's Dolphins to determine their trophic level and assess any possible impact of the fishing industry on food resources.
- Determine taxonomic relationships between Fraser's Dolphins within and outside the Indo-Pacific region to assess the likely impact of threats on possible individual populations.
Projects initiated to address these threats include a requirement to report all incidental catches made within the Australian EEZ, and a review of incidental catch from fisheries operating in the Arafura and Timor seas (19811985) commissioned by the Australian National Parks and Wildlife Service (Bannister et al. 1996).
Additional conservation action suggested for Fraser's Dolphin includes:
- Conduct a sighting program to monitor abundance, especially in offshore waters.
- Report and salvage of specimens incidentally caught or stranded.
- Ensure specimens are made available to appropriate scientific museums to enable collection of life history data and tissue samples for genetic analysis.
- Ensure adequate protection of species and resources in Australian and nearby waters.
- Conduct disentanglement workshops, particularly for offshore fishers, and develop suitable action plans (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.
Fraser's dolphin has been identified as a conservation value in the North-west (DSEWPaC 2012y) Marine Region. The "species group report card - cetaceans" for the North-west (DSEWPaC 2012y) Marine Region provides additional information.
The following documents may inform protection and management:
- The Action Plan for Australian Cetaceans (Bannister et al. 1996).
- Review of the Conservation Status of Australia's Smaller Whales and Dolphins (Ross 2006).
- Australian National Guidelines for Whale and Dolphin Watching (Department of the Environment and Heritage 2005e).
- The North Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North Marine Region (DEWHA 2008).
- North-West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North-West Marine Region (DEWHA 2008b).
- Threat abatement plan for the impacts of marine debris on vertebrate marine life (DEWHA 2009t).
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:Harvest by gill netting|
|Biological Resource Use:Fishing and Harvesting Aquatic Resources:Mortality due to capture, entanglement/drowning in nets and fishing lines|
|Biological Resource Use:Fishing and Harvesting Aquatic Resources:Overfishing, competition with fishing operations and overfishing of prey fishing|
|Pollution:Garbage and Solid Waste:Ingestion and entanglement with marine debris|
|Pollution:Industrial and Military Effluents:Leakage of industrial waste|
|Pollution:Pollution:Deterioration of water and soil quality (contamination and pollution)|
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.
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.
Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008). The North Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North Marine Region. [Online]. Canberra: DEWHA. Available from: http://www.environment.gov.au/resource/north-marine-bioregional-plan-bioregional-profile-description-ecosystems-conservation.
Department of the Environment, Water, Heritage and the Arts (DEWHA) (2008b). North-West Marine Bioregional Plan: Bioregional Profile: A Description of the Ecosystems, Conservation Values and Uses of the North-West Marine Region. [Online]. Canberra: DEWHA. Available from: http://www.environment.gov.au/coasts/mbp/publications/north-west/bioregional-profile.html.
Department of the Environment, Water, Heritage and the Arts (DEWHA) (2009t). Threat abatement plan for the impacts of marine debris on vertebrate marine life. [Online]. Available from: http://www.environment.gov.au/biodiversity/threatened/publications/tap/marine-debris.html.
Findlay, K.P., P.B. Best, G.J.B Ross & V.G. Cockcroft (1992). Distribution of Small Odontocete Cetaceans off the Coasts of South Africa and Namibia. South African Journal of Marine Science. 12:237-270.
LeDuc, R.G., W.F. Perrin & A.E. Dizon (1999). Phylogenetic relationships among the delphinid cetaceans based on full cytochrome b sequences. Marine Mammal Science. 15:619-648.
Louella, M. & L. Dolar (2002). Fraser's Dolphin Lagenodelphis hosei. In: Perrin, W.F., Wursig, B., & Thewissen, J.G.M., eds. Encyclopedia of Marine Mammals. Page(s) 485-487. London, Academic Press.
Mörzer Bruyns, W.F.J. (1971). Field Guide of Whales and Dolphins. Mees, Amsterdam.
McColl, K.A. & D.L. Obendorf (1984). Helminth parasites and associated pathology in stranded Fraser's dolphins, Lagenodelphis hosei (Fraser, 1956). Aquatic Mammals. 9:30-34.
Peddemors, V.M. & R. Harcourt (2006). Personal Communication. Sydney: Graduate School of the Environment, Macquarie University.
Perrin, W.F, P.B. Best, W.H. Dawbin, K.C. Balcomb, R. Gambell & G.J.B. Ross (1973). Rediscovery of Fraser's Dolphin Lagenodelphis hosei. Nature. 241:345-350.
Ross, G.J.B. (1984). The smaller cetaceans of the south-east coast of southern Africa. Annals of the Cape Provincial Museums (Natural History). 15:173-411.
Ross, G.J.B. (2006). Review of the Conservation Status of Australia's Smaller Whales and Dolphins. Page(s) 124. [Online]. Report to the Australian Department of the Environment and Heritage, Canberra. Available from: http://www.environment.gov.au/resource/review-conservation-status-australias-smaller-whales-and-dolphins.
van Bree, P.J.H., A. Collet, G. Desportes, E. Hussenote & J.A. Raga (1986). Le dauphin de Fraser, Lagenodelphis hosei (Cetacea, Odontoceti), espèce nouvelle pour la faune d'Europe. Mammalia. 50:57-86. Paris, France: Muséum national d'Histoire naturelle, Publications Scientifiques.
This database is designed to provide statutory, biological and ecological information on species and ecological communities, migratory species, marine species, and species and species products subject to international trade and commercial use protected under the Environment Protection and Biodiversity Conservation Act 1999 (the EPBC Act). It has been compiled from a range of sources including listing advice, recovery plans, published literature and individual experts. While reasonable efforts have been made to ensure the accuracy of the information, no guarantee is given, nor responsibility taken, by the Commonwealth for its accuracy, currency or completeness. The Commonwealth does not accept any responsibility for any loss or damage that may be occasioned directly or indirectly through the use of, or reliance on, the information contained in this database. The information contained in this database does not necessarily represent the views of the Commonwealth. This database is not intended to be a complete source of information on the matters it deals with. Individuals and organisations should consider all the available information, including that available from other sources, in deciding whether there is a need to make a referral or apply for a permit or exemption under the EPBC Act.
Citation: Department of the Environment (2014). Lagenodelphis hosei in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Sun, 24 Aug 2014 01:12:09 +1000.