Mesoplodon layardii

Taxonomy

Assessment Information

Geographic Range

Population

Habitat and Ecology

Threats

Conservation Actions

Taxonomy [top]

Kingdom	Phylum	Class	Order	Family
ANIMALIA	CHORDATA	MAMMALIA	CETARTIODACTYLA	ZIPHIIDAE

Scientific Name:

Mesoplodon layardii

Species Authority

(Gray, 1865)

Common Name/s:

English	–	Strap-toothed Whale, Layard's Beaked Whale
French	–	Mésoplodon De Layard
Spanish	–	Ballena De Pico De Layard, Zifio De Layard

Assessment Information [top]

Red List Category & Criteria:

Data Deficient ver 3.1

Year Assessed:

2008

Assessor/s

Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L.

Evaluator/s:

Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority)

Justification:
There is no information on global abundance or trends in abundance for this species. It is not believed to be uncommon but it is potentially vulnerable to low-level threats and a 30% global reduction over three generations cannot be ruled out (criterion A).

History:

1996	–	Data Deficient (Baillie and Groombridge 1996)
1994	–	Insufficiently Known (Groombridge 1994)

Geographic Range [top]

Range Description:	Strap-toothed beaked whales apparently have a continuous distribution in cold temperate waters of the Southern Hemisphere, mostly between 35° and 60°S; there have been strandings in South Africa, Australia, Tasmania, New Zealand, the Kerguelen Islands, Heard Island, Argentina, Uruguay, Brazil, and the Falkland Islands (MacLeod et al. 2006). The seasonality of strandings suggests that this species may migrate. Like all beaked whales, they occur mostly in deep waters beyond the edge of the continental shelf. There is some evidence of sexual segregation in distribution.
Countries:	Native: Argentina (Chubut, Tierra del Fuego); Australia (New South Wales, South Australia, Tasmania, Victoria, Western Australia); Brazil; Chile (Magellanes); Falkland Islands (Malvinas); French Southern Territories (the) (Kerguelen); Heard Island and McDonald Islands; New Zealand (Chatham Is., North Is., South Is.); South Africa (Western Cape Province); Uruguay Presence uncertain: Antarctica
FAO Marine Fishing Areas:	Native: Atlantic – southeast; Atlantic – southwest; Atlantic – Antarctic; Indian Ocean – western; Indian Ocean – Antarctic; Indian Ocean – eastern; Pacific – southeast; Pacific – southwest
Range Map:	(click map to view full version)

Population [top]

Population:	There is little information available on the status of the strap-toothed whale, but based on the number of strandings, it is probably not a rare species compared to its congeners. There is no information on trends in the global abundance of this species.
Population Trend:	Unknown

Habitat and Ecology [top]

Habitat and Ecology:	Like all beaked whales, these whales occur mostly in deep waters beyond the edge of the continental shelf. The diet is comprised nearly entirely of oceanic squids, some occurring to great depths (Sekiguchi et al. 1996).
Systems:	Marine

Threats [top]

Major Threat(s):	Direct hunting has never been associated with this species. Pervasive gillnet and longline fisheries throughout the species' range raises concern that some bycatch is likely. Even low levels of bycatch might cause unsustainable impacts on this group of naturally rare cetaceans. This species, like other beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006). As a cold to temperate water species, the strap-toothed whale may be vulnerable to the effects of climate change as ocean warming may result in a shift or contraction of the species range as it tracks the occurrence of its preferred water temperatures (Learmonth et al. 2006). The effect of such changes in range size or position on this species is unknown. Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001); this species may also be at risk. Predicted impacts of global climate change on the marine environment may affect this species of whale, although the nature of impacts is unclear (Learmonth et al. 2006).

Major Threat(s):

Direct hunting has never been associated with this species. Pervasive gillnet and longline fisheries throughout the species' range raises concern that some bycatch is likely. Even low levels of bycatch might cause unsustainable impacts on this group of naturally rare cetaceans.

This species, like other beaked whales, is likely to be vulnerable to loud anthropogenic sounds, such as those generated by navy sonar and seismic exploration (Cox et al. 2006).

As a cold to temperate water species, the strap-toothed whale may be vulnerable to the effects of climate change as ocean warming may result in a shift or contraction of the species range as it tracks the occurrence of its preferred water temperatures (Learmonth et al. 2006). The effect of such changes in range size or position on this species is unknown.

Evidence from stranded individuals of several similar species indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001); this species may also be at risk.

Predicted impacts of global climate change on the marine environment may affect this species of whale, although the nature of impacts is unclear (Learmonth et al. 2006).

Conservation Actions [top]

Conservation Actions:	The species is listed in Appendix II of CITES. Research is needed to determine the impacts of potential threatening processes on this species.

Conservation Actions:

The species is listed in Appendix II of CITES. Research is needed to determine the impacts of potential threatening processes on this species.

Citation:	Taylor, B.L., Baird, R., Barlow, J., Dawson, S.M., Ford, J., Mead, J.G., Notarbartolo di Sciara, G., Wade, P. & Pitman, R.L. 2008. Mesoplodon layardii. In: IUCN 2008. 2008 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 19 November 2008.
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