Taxonomy
Lagenorhynchus acutus | Atlantic White-sided Dolphin
Distribution
Status
Conservation status
| HABITATS DIRECTIVE ARTICLE 17 REPORTING |
| Range | Favourable |
| Population | Favourable |
| Habitat | Favourable |
| Future Prospects | Favourable |
| Overall Assessment of Conservation Status | Favourable |
| Overall Trend in Conservation Status | Favourable |
IUCN Conservation Status |
| Ireland | Not evaluated* |
| Europe (1) | Least concern |
| Global (2) | Least concern |
* There is currently no Irish Red List for Marine Mammals.
Legal status
Protected by the following legal instruments:
- Habitats Directive (92/43/EEC) Annex IV
- Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention) Appendix II
- Convention on the Conservation of Migratory Species of Wild Animals (Bonn Convention) Appendix II*
- Convention on Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II
- Council Regulation (EC) No. 812/2004
- Wildlife Act (1976)
- Wildlife (Amendment) Act (2000)
- Whale Fisheries Act 1937
Native status
The 2008 IUCN Global Red List for this species lists Ireland as one of the countries where it is native.
Source: Hammond, P.S. et al 2008.
Records would seem to imply that the Atlantic White-sided Dolphin is present in Irish waters from December to June, although this variation could be related to recording effort. Strandings data however appear to mirror records of live animal seasonal distribution.
Source: Wall D.et al 2013.
There are some indications that the species is generally more pelagic but may migrate closer to shore seasonally in response to movements of prey.
Source: Boris Culik 2010.
As there is insufficient information on seasonal distribution in Irish waters, for the purposes of this profile Lagenorhynchus acutus is considered as native.
Species Biology
Identification
- Maximum body length: Adult male 2.8m, adult female 2.5m.
- Average body length: Adult 2.4 - 2.8m
- Head shape: Gently sloping forehead.
- Beak: Beak is short, black above and white below. Teeth are sharp and conical, 58 - 80 in the upper row, 58 - 80 lower jaw.
- Dorsal fin: Tall, falcate, sharply pointed with narrow base, located mid-back.Their name derives from the Latin acutus ("sharp"), referring to the acutely pointing dorsal fin.
- Colouration: Black back, top of beak, flippers and flukes. Grey sides, white belly. White band below dorsal fin connects with yellow band on tailstock.
- Body: The body is robust, with a gently sloping forehead and the tailstock is strongly truncated. Flippers are sickle shaped and pointed.
Habitat
Habitat varies from pelagic to continental shelf and continental shelf slopes.
Source: Harris S., Yalden D.W. 2008.
In the eastern north Atlantic the species has been observed some way up the Saint Lawrence River in Canada.
Source: European Mammal Assessment team, 2007.
Habitats include but are not necessarily limited to;
- Open marine water (MW1)
Sources: Harris S., Yalden D.W. 2008.; Fossitt, J.A., 2001.
Reproduction
- Max estimated life expectancy: Female 27 years, Male 22 years.
- Female sexual maturity: 6-12 years
- Male sexual maturity: 7-11 years.
- Gestation period: Approximately 11 months
- Calving: May-August.
Threats faced
| THREAT | ARTICLE 17 THREAT CODE | RANKING | |
| Seismic exploration, explosions | H06.05 | Medium | |
| Fishing and harvesting aquatic resources* | F02 | Medium | |
| Death or injury by collision | G05.11 | Low | |
| Noise nuisance, noise pollution | H06.01 | Low | |
| Marine water pollution | H03 | Low | |
| Changes in abiotic conditions | M01 | Low | |
| Threats and pressures from outside the EU territory | XE | Low |
*This would include the threat to this species of becoming by-catch / accidental catch as well as the threat of a reduction in prey availability and also entanglement in fishing gear.
These threats accord well with threats outlined in the 2007 European Regional IUCN Red List assessment for the species which did not identify any other threats that are currently relevant in Irish waters.
Source: IUCN SSC Cetacean Specialist Group 2007.
Conservation actions
In the Article 17 Habitats Directive reporting for the period 2007-2012 no Conservation Measures in place or in the process of being implemented during the period were listed for this species.
Source: NPWS 2013.
Suggested Conservation Actions in the 2007 European Regional IUCN Red List Assessment included;
- Further observer studies of bycatch rates.
In a 2009 Cetacean Action Plan a total of 41 Actions were identified as part of the plan. The plan and the 2013 review of the plan are available from the NPWS website.
Source: DEHLG 2009.
Distribution
World distribution(GBIF)
North Atlantic species of temperate to sub-arctic areas, including the continental shelf, slope and deep canyons. Recorded to south of Greenland and off Svalbard, and as far south as the straits of Gibraltar.
Source: European Mammal Assessment team, 2007.
Accuracy of world distribution shown in the Global Biodiversity Information Facility (GBIF) map below will be constrained by, amongst other factors, data held but not shared by countries and organizations not participating in the GBIF.
Irish distribution
Highest relative abundance of records in deep waters off the northwest coast (Rockall Trugh). Less commonly recorded in inshore waters.
Source: Wall D.et al 2013.
.
Temporal change
Records submitted to Data Centre in 2024
The following map is interactive. If you would prefer to view it full screen then click here.
How can you help
The National Biodiversity Data Centre is trying to
improve our knowledge on the distribution of the Atlantic White-sided Dolphin in
Ireland. Should you observe this species, please submit
sightings to add to the database. Detailed observations will assist us
gaining a better insight into where the species
is most abundant in Ireland and we might also be able to detect
regional variations. Please submit any sightings and photographs at:
http://records.biodiversityireland.ie/index.php
All
records submitted online can be viewed on Google Maps – once checked
and validated these will be added to the database and made available for
conservation and research.
Further information
For further information contact Dr. Liam Lysaght llysaght@biodiversityireland.ie
References
Publications
Culik, B. (2010) Odontocetes. The toothed whales: "Lagenorhynchus acutus". UNEP/CMS Secretariat, Bonn, Germany.http://www.cms.int/small-cetaceans
DEHLG (2009) Conservation Plan for Cetaceans in Irish waters.
Fossitt, J.A. (2001) A Guide to Habitats in Ireland. The Heritage Council
Hammond, P.S., Bearzi, G., Bjørge, A., Forney, K., Karczmarski, L., Kasuya, T., Perrin, W.F., Scott, M.D., Wang, J.Y., Wells, R.S. & Wilson, B. 2008. Lagenorhynchus acutus. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 14 October 2014.
Harris S., Yalden D.W. (2008). Mammals of the British Isles :Handbook, 4th Edition. The Mammal Society.
Species account by IUCN SSC Cetacean Specialist Group; regional assessment by European Mammal Assessment team 2007. Lagenorhynchus acutus. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 14 October 2014.
NPWS (2013) The Status of EU Protected Habitats and Species in Ireland. Species Assessments Volume 3. Version 1.0. Unpublished Report, National Parks & Wildlife Services. Department of Arts, Heritage and the Gaeltacht, Dublin, Ireland.
NPWS (2013a) Delivery Schedule for Actions listed in the Conservation Plan for Cetaceans in Irish waters – June 2013
Wall, D., Murray, C., O’Brien, J., Kavanagh, L., Wilson, C., Ryan, C., Glanville, B., Williams, D., Enlander, I., O’Connor, I., McGrath, D., Whooley, P. & Berrow, S. (2013). Atlas of the Distribution and Relative Abundance of Marine Mammals in Irish Offshore Waters: 2005 – 2011. Irish Whale and Dolphin Group, Kilrush, Co. Clare.