|Scientific Name:||Mesoplodon europaeus|
|Species Authority:||(Gervais, 1855)|
Mesoplodon gervaisi (Deslongchamps, 1866)
|Red List Category & Criteria:||Data Deficient ver 3.1|
|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.|
|Reviewer(s):||Hammond, P.S. & Perrin, W.F. (Cetacean Red List Authority)|
There is little information on abundance and none on 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).
|Range Description:||Although sometimes depicted as a North Atlantic endemic, this species is probably continuously distributed in deep waters across the tropical and temperate Atlantic Ocean, both north and south of the equator (Mead 1989; MacLeod et al. 2006). Most records are from the east and Gulf coasts of North America, from New York to Texas, but Gervais' beaked whales are also known from several of the Caribbean islands. This is the most commonly-stranded beaked whale in the southeastern United States. In the eastern Atlantic, they are known from Ireland to Guinea-Bissau in West Africa. There is only one record of this species entering the Mediterranean, and it is considered a vagrant (Podesta et al. 2005). There are also strandings at Ascension Island in the central South Atlantic (Mead 1989), and along the coast of Brazil (de Oliveira Santos et al. 2003). There is speculation that its Southern Hemisphere distribution could extend to Uruguay and Angola .|
Native:Bahamas; Brazil; Cape Verde; Cuba; France; Guinea-Bissau; Ireland; Jamaica; Mauritania; Saint Helena, Ascension and Tristan da Cunha (Ascension, Tristan da Cunha); Spain (Canary Is., Spain (mainland)); Trinidad and Tobago; United Kingdom; United States
|FAO Marine Fishing Areas:||
Atlantic – northwest; Atlantic – western central
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||No estimates of abundance exist for the species; however, estimates indicate that 106 (CV=41%) beaked whales of the genus Mesoplodon occur in the northern Gulf of Mexico, considered to be either M. densirostris or M. europaeus (Mullin and Fulling, 2004). Based on the frequency with which they strand, they are presumed to be relatively common in waters along the east coast of North America.|
|Habitat and Ecology:||
The favored habitat of Gervais' beaked whales appears to be warm temperate and tropical waters (Norman and Mead 2001). Like other members of the genus, the species prefers deep waters based on the presence of prey from such habitats in stomach contents and a lack of sightings near shore (Mead 1989). Strandings and the few possible sightings suggest that the species prefers tropical and subtropical waters (MacLeod et al. 2006).
Like other members of the genus, Gervais’ beaked whales are known to feed primarily on squid, although some fish may be taken as well (Norman and Mead 2001). There is also a record of a mysid shrimp found in the stomach of a stranded specimen. Stable isotope analysis has found that this species feeds at a similar trophic level to other Mesoplodon species with which it is sympatric, but at lower trophic level than Cuvier’s beaked whale which suggests that it feeds on smaller prey than this latter species (MacLeod et al. 2005).
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).
In particular, several atypical mass strandings of beaked whales, including Gervais' beaked whales, were associated with naval activities: mid to late 1980s on the Canary Islands (Waring et al. 2006), in March 2000 on the Bahamas (Rowles et al. 2000, Anonymous 2001) and again in September 2002 during a naval NATO manoeuvre involving low frequency sonar around the Canaries (Vidal pers. comm.).
Evidence from stranded individuals of several species, including Mesoplodon europaeus, indicates that they have swallowed discarded plastic items, which may eventually lead to death (e.g. Scott et al. 2001).
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.
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:||The species is listed in Appendix II of CITES. Research is needed to determine the impacts of potential threatening processes on this species.|
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Balcomb, K. C. and Claridge, D. E. 2001. A mass stranding of cetaceans caused by naval sonar in the Bahamas. Bahamas Journal of Science 8(2): 2-12.
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Learmonth, J. A., Macleod, C. D., Santos, M. B., Pierce, G. J., Crick, H. Q. P. and Robinson, R. A. 2006. Potential effects of climate change on marine mammals. Oceanography and Marine Biology: An Annual Review 44: 431-464.
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MacLeod, C. D., Santos, M. B., Lopez, A. and Pierce, G. J. 2005. Relative prey size consumption in toothed whales: implications for prey selection and level of specialization. Marine Ecology Progress Series 326: 295-307.
Malakoff, D. 2002. Suit ties whale deaths to research cruise. Science 298: 722-723.
Mead, J. G. 1989. Beaked whales of the genus Mesoplodon. In: S. H. Ridgway and R. Harrison (eds), Handbook of marine mammals, Vol. 4: River dolphins and the larger toothed whales, pp. 349-430. Academic Press.
Mullin, K. D. and Fulling, G. L. 2004. Abundance of cetaceans in the oceanic northern Gulf of Mexico, 1996-2001. Marine Mammal Science 20(4): 787-807.
Norman, S. A. and Mead, J. G. 2001. Mesoplodon europaeus. Mammalian Species 688: 1-5.
Oliveira Santos, M. C., de, Zampirolli, E., de Castro, A. F. V. and Alvarenga, F. S. 2003. A Gervais' beaked whale (Mesoplodon europaeus>) washed ashore in southeastern Brazil: extra limital record? Aquatic Mammals 29: 404-410.
Podesta, M., Cagnolaro, L. and Cozzi, B. 2005. First record of a stranded Gervais' beaked whale, Mesoplodon europaeus (Gervais, 1855), in the Mediterranean Sea. Atti della Societa Italiana di Scienze Naturali e del Museo Civico di Storia Naturele di Milano 146: 109-116.
Rowles, T., Ketten, D., Ewing, R., Whaley, J., Bater, A. and Gentry, R. 2000. Mass stranding of multiple cetacean species in the Bahamas on March 15-17, 2000. International Whaling Commission, Cambridge, UK.
Scott, M. D., Hohn, A. A., Westgate, A. J., Nicolas, J. R., Whitaker, B. R. and Campbell, W. B. 2001. A note on the release and tracking of a rehabilitated pygmy sperm whale (Kogia breviceps). Journal of Cetacean Research and Management 3(1): 87-94.
Wang, J. Y. and Yang, S. C. 2006. Unusual cetacean stranding events of Taiwan in 2004 and 2005. Journal of Cetacean Research and Management 8: 283-292.
Waring, G. T., Josephson, E., Fairfield, C. P. and Maze-Foley, K. (eds). 2006. U.S. Atlantic and Gulf of Mexico marine mammal stock assessments - 2005. NOAA Technical Memorandum NMFS-NE, pp. 346 pp..
|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 europaeus. The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 21 December 2014.|