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|
|Policy Statements and Guidelines||
Industry Guidelines on the Interaction between offshore seismic exploration and whales (Department of the Environment and Water Resources (DEW), 2007h) [Admin Guideline].
Australian National Guidelines for Whale and Dolphin Watching (Department of the Environment and Heritage, 2005e) [Information Sheet].
|Scientific name||Tasmacetus shepherdi |
This is an indicative distribution map of the present distribution of the species based on best available knowledge. See map caveat for more information.
Scientific name: Tasmacetus shepherdi
Common name: Shepherds' Beaked Whale
Other names: Tasman Beaked Whale
Shepherds' Beaked Whale was originally described by Oliver in 1937, and is a well recognised taxon. No subspecies are currently recognised (Bannister et al. 1996; Rice 1998).
Shepherd's Beaked Whales display many of the standard features of beaked whales, including a distinct beak protruding from a relatively steep forehead. However, their dentition is unique. Both the upper and lower jaws are lined with many (17-29) small conical teeth, while two larger teeth at the tip of the lower jaw remain un-erupted in females. The line of the mouth is straight. The flippers are small and rounded, while the short, falcate (sickle-shaped) dorsal fin is set far back. Generally, the notch between the tail flukes (present in most cetaceans) is absent (Jefferson et al. 1993; Leatherwood & Reeves 1983). The throat has the usual pair of V-shaped creases. The crescent-shaped blow-hole on top of the head is asymmetric, with the right margin extending further forward than the left (Leatherwood & Reeves 1983).
Most morphological descriptions are based on examination of carcasses of stranded whales that are often partly decomposed. Hence, the colour pattern is not well described. The body appears to be largely countershaded dark grey above and lighter below. There are often several dark diagonal bands on the sides (Jefferson et al. 1993).
The maximum weight is about 2.0-2.5 tonnes, while the maximum lengths reported for males and females are 7.10 m and 6.60 m respectively. It is possible that males reach even larger sizes however, and MacLeod and D'Amico (2006) state that a putative Shepherd's Beaked Whale measured 9.1 m.
There are two unconfirmed near-shore sightings, of a lone individual in New Zealand and a group of three Shepherd's Beaked Whales in Western Australia. These animals showed their beak when breathing, but the blow was inconspicuous (Ross 2006).
In Australia, Shepherd's Beaked Whales are known from only three stranded specimens (South Australia and Western Australia) and an unconfirmed sighting of a group of three in Western Australia (Baker 1990; Bannister et al. 1996; Ross 2006). This species apparently prefers subantarctic (18 °C) and adjacent temperate (1020 °C) deep oceanic waters and is therefore only likely to be present in the offshore Australian Exclusive Economic Zone (EEZ) waters between 33° S and 50° S (Ross 2006). No key localities are known in Australian waters (Bannister et al. 1996).
The current extent of occurrence for Shepherd's Beaked Whale is estimated to be greater than 20 000 km² (based on the Australian EEZ (200 nm, between 33º S and 50° S and generally deeper than 200 m)) (V.M. Peddemors & R. Harcourt 2006, pers. comm.). Increasing ocean temperatures predicted by climate change scenarios could potentially decrease the extent of occurrence, with warmer water extending southwards beyond 33° S.
Shepherd's Beaked Whales are considered to occur in one location as deep water is not a barrier to movement in this species, and there are no known unsurpassable pelagic boundaries in the region.
No distribution fragmentation is anticipated for Shepherd's Beaked Whale in Australian oceanic subantarctic and cold temperate waters.
Shepherd's Beaked Whales have a circumpolar distribution in mid-latitudes of the Southern Hemisphere from 33° to 50° S. They are known from only 19 stranded specimens and two unconfirmed sightings, mostly from New Zealand (12), but also from Australia (three: South Australia and Western Australia), Tristan da Cunha (two), Argentina (three) and Chile (one) (Baker 1990; Bannister et al. 1996; Goodall 1978; Mead 1989b; Ross 2006). This species apparently prefers subantarctic (18 °C) and adjacent temperate (1020 °C) deep oceanic waters. It is possible that there is a northward movement of Shepherd's Beaked Whales in summer, approaching continental seas.
There are no estimates of Shepherd's Beaked Whale population size, either globally or for Australia, so the proportion of the global population in Australian waters is unknown. It is unlikely that Australian Shepherd's Beaked Whales are a distinct population, as no subspecies are recognized. As a deep water species primarily living off the continental shelf, incidental bycatch of animals in neighbouring countries and/or international waters may affect the Australian population.
Worldwide, Shepherd's Beaked Whale is not well surveyed. Their distribution is primarily assumed from stranded specimens, plus occasional sightings.
The population size of Shepherd's Beaked Whale in Australian waters is unknown. Shepherd's Beaked Whales are not considered abundant as sightings and strandings are rare. The species therefore potentially includes less than 10 000 mature individuals within Australian waters (V.M. Peddemors & R. Harcourt 2006, pers. comm.).
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). Shepherd's Beaked Whales are also subject to International Whaling Commision (IWC) regulations and protected within the Indian Ocean Sanctuary and Southern Ocean Sanctuary.
Shepherd's Beaked Whales are probably exclusively oceanic, deep water animals. The unconfirmed sighting of three individuals off Western Australia is possibly related to the deep trenches/canyons in the region, allowing deep water species to come closer to land.
There is no known life history data for Shepherd's Beaked Whale (Mead 1989b; Ross 2006). Life expectancy of other beaked whale species ranges from 27 to 84 years (Baird's Beaked Whale, Berardius bairdii) (Mead 1989b; MacLeod & D'Amico 2006). Natural causes of mortality are poorly understood, but are thought to include predation, disease and effects associated with 'old age' (MacLeod & D'Amico 2006).
While no data have been recorded for any breeding parameter (Ross 2006), a suspected calving interval of two to three years leads to a slow reproductive capacity.
The diet of Shepherd's Beaked Whale is poorly known. The presence of rows of sturdy functional teeth in both jaws suggests that Shepherd's Beaked Whale may consume more fish than other ziphiids (beaked whales). The bulk of the stomach contents of one Argentinean specimen consisted of otoliths of an unidentified brotulid fish, an un-identified serranid and Merluccius hubbsi. Other remains included a small crab (Peltarion spinulosum, which occurs in near-shore waters to 77 fathoms), and one small squid beak. However, these two latter species were possibly the prey of ingested fish (Bannister et al. 1996).
A powerful and active predator, Shepherd's Beaked Whale is presumed to be able to dive deeply in pursuit of prey. The precise function of the pair of V-shaped throat grooves (a feature of ziphiids) is unknown, but their arrangement suggests a capacity for suck-feeding, where prey is sucked into the mouth and swallowed whole (Ross 2006). This suck-feeding habit may increase the likelihood of plastic or debris ingestion.
The presence of small conical teeth along both the upper and lower jaw is a distinctive feature of Shepherd's Beaked Whale, and should allow discrimination from the other beaked whales.
Beaked whales are notoriously difficult to identify at sea due to their propensity to spend little time at the surface, breathing only a few times before submerging for extensive periods. Whilst at the surface they are slow moving and inconspicuous, and generally do not 'blow'.
During the two unconfirmed near-shore sightings of live Shepherd's Beaked Whales, the animals showed their beak when breathing and had an inconspicuous blow. As no good descriptions of colouration exist, it would be difficult to distinguish Shepherd's Beaked Whale from other ziphiids at sea.
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.
Surveys for oceanic cetaceans have primarily been boat-based transects, although some aerial surveys have been conducted in the eastern tropical Pacific. There are almost no dedicated cetacean surveys conducted in Australian waters, but surveys associated with petro-chemical exploration may be used as platforms of opportunity. During such non-dedicated surveys, a minimum requirement is to record all cetacean sightings encountered with corresponding GPS position, environmental data (sea conditions and habitat) and behavioural observations. From fishing vessels, all incidentally caught animals should be recorded with corresponding GPS position, plus attempts should be made to obtain basic biological information from dead animals (V.M. Peddemors 2006, pers. comm.).
No past threats to Shepherd's Beaked Whale are known. The current threats posed to Shepherd's Beaked Whales include possible entanglement in drift nets and other nets set, lost or discarded in international waters.
Recently, there have been a number of studies investigating the impacts of anthropogenic noise on beaked whales, particularly activities that transmit sounds into the water column. These studies have, in part, been driven by mass strandings of beaked whales coinciding temporally and spatially with naval manoeuvres (MacLeod & D'Amico 2006). For example, necropsies (autopsies) of stranded Blainville and Cuvier's Beaked Whales following low frequency acoustic sonar tests have revealed tissue trauma associated with an acoustic or impulse injury that caused the animals to strand (Frantzis 1998). It has been noted that beaked whales with average group sizes of less than 20, and particularly groups composed primarily of immature, juvenile or cow-calf pairs, may be more susceptible to strandings associated with anthropogenic noise, although it is not known why this might be the case. Anthropogenic sounds may disrupt or interfere with the sounds produced by beaked whales, including disruption of navigation, and/or interfere with social communication. While data is limited, where there is data beaked whales appear to use relatively high frequency echolocation (up to 120 kHz or more) and non-echolocation sounds in the region of one to 16 kHz (MacLeod & D'Amico 2006).
Other potential threats to Shepherd's Beaked Whale include competition from expanding commercial fisheries in higher latitudes and pollution leading to accumulation of toxic substances in body tissues.
Although little is known about reproduction in beaked whales, it is likely that Shepherd's Beaked Whale have a low reproductive rate, producing one offspring every two to three years. This means that population recovery is a slow process.
Bannister and colleagues (1996) and Ross (2006) recommended the following actions be taken to better understand the threats to Shepherd's Beaked Whale:
- Determine the distribution and monitor abundance of Shepherd's Beaked Whale in Australian waters to assess the possible impact of threats, particularly the effect of direct and indirect fishing activities. This should be done via a sighting program to monitor numbers, particularly in southern waters.
- Obtain information on Shepherd's Beaked Whale diet to determine their trophic level and assess any possible impact of the fishing industry on beaked whale food resources.
- Obtain basic biological information (including diet and pollutant levels) from incidentally-caught and stranded Shepherd's Beaked Whale specimens, and ensure specimens are made available to appropriate scientific museums to enable collection of life history data and tissue samples for genetic analysis.
Current projects initiated to address these threats include a requirement to report all incidental catches made within the Australian EEZ; the development of suitable action plans; and conducting disentanglement workshops, targeted particularly at offshore fishers (Bannister et al. 1996).
The Action Plan for Australian Cetaceans (Bannister et al. 1996) and the Review of the Conservation Status of Australia's Smaller Whales and Dolphins (Ross 2006) provide brief biological overviews and management recommendations of this species. In addition, Industry Guidelines on the interaction between offshore seismic exploration and whales (DEW 2007h), and Australian National Guidelines for Whale and Dolphin Watching (Department of the Environment and Heritage 2005e) have been published.
No threats data available.
Baker, A. (1990). Whales and Dolphins of Australia and New Zealand: An Identification Guide. Page(s) 133 pp. Wellington, New Zealand: Victoria University Press.
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/coasts/publications/cetaceans-action-plan/pubs/whaleplan.pdf.
Department of the Environment and Heritage (2005e). Australian National Guidelines for Whale and Dolphin Watching. [Online]. Available from: http://www.environment.gov.au/coasts/publications/whale-watching-guidelines-2005.html.
Department of the Environment and Water Resources (DEW) (2007h). Industry Guidelines on the Interaction between offshore seismic exploration and whales. [Online]. Available from: http://www.environment.gov.au/epbc/publications/seismic.html.
Frantzis, A. (1998). Does acoustic testing strand whales?. Nature. 392:29.
Goodall, R.N.P. (1978). Report on small cetaceans stranded on the coasts of Tierra del Fuego. Scientific Reports of the Whale Research Institute Toyko. 30:197-230.
Jefferson, T.A., S. Leatherwood & M.A. Webber (1993). FAO species identification guide. Marine Mammals of the World. [Online]. Rome: United Nations Environment Programme, Food and Agricultural Organization. Available from: ftp://ftp.fao.org/docrep/fao/009/t0725e/t0725e00.pdf. [Accessed: 15-Aug-2007].
Leatherwood, S. & R.R. Reeves (1983). The Sierra Club Handbook of Whales and Dolphins. San Francisco: Sierra Club Books.
MacLeod, C.D. & A. D'Amico (2006). A review of beaked whale behaviour and ecology in relation to assessing and mitigating impacts of anthropogenic noise. Journal of Cetacean Research and Management. 7(3):211-221.
Mead, J.G. (1989b). Shepherd's beaked whale Tasmacetus shepherdi Oliver, 1937. In: Ridgway, S H and R. Harrison, eds. In: Handbook of Marine Mammals Vol. 4: River Dolphins and the Larger Toothed Whales. Page(s) 309-320.
Peddemors, V.M. (2006). Personal Communications. Sydney: Graduate School of the Environment, Macquarie University.
Peddemors, V.M. & R. Harcourt (2006). Personal Communication. Sydney: Graduate School of the Environment, Macquarie University.
Rice, D.W. (1998). Marine mammals of the world. Systematics and distribution. Special publication number 4. Kansas: Society for Marine Mammalogy.
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/coasts/publications/pubs/conservation-smaller-whales-dolphins.pdf.
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 (2013). Tasmacetus shepherdi in Species Profile and Threats Database, Department of the Environment, Canberra. Available from: http://www.environment.gov.au/sprat. Accessed Sat, 21 Dec 2013 13:06:05 +1100.