Taxonomy
Balaenoptera musculus | Blue Whale
Distribution
Status
Conservation status
| HABITATS DIRECTIVE ARTICLE 17 REPORTING |
| Range | Favourable |
| Population | Unknown |
| Habitat | Favourable |
| Future Prospects | Unknown |
| Overall Assessment of Conservation Status | Unknown |
| Overall Trend in Conservation Status | N / A |
IUCN Conservation Status |
| Ireland | Not Evaluated* |
| Europe (1) | Endangered (D) |
| Global (2) | Endangered (A1abd) |
* 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 I
- Convention on Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix I
- The Convention for the Protection of the marine Environment of the North-East Atlantic (OSPAR)
- International Convention for the Regulation of Whaling 1946 (as amended)
- Council Regulation (EC) No. 812/2004
- Wildlife Act (1976)
- Wildlife (Amendment) Act (2000)
- Whale Fisheries Act 1937
Native status
It is thought that Blue Whales in Irish waters are, for the most part, migrating between Icelandic feeding grounds and tropical breeding grounds.
Source: Irish Whale and Dolphin Group
The 2008 IUCN Global Red List for this species lists Ireland as one of
the countries where it is native, however it probably better described
as a migrant in an Irish context.
Sources: Reilly, S.B. et al 2008.; de Klem, 1994
Species Biology
Identification
- Max. adult body length: 31-33m
- Max. adult weight: 178 tonnnes
- Average adult body lengtht: 25m
- Average adult weight: 80-130 tonnes
- Average length of calf at birth: 7m
- Average weight of calf at birth: 2.5 - 4 tonnes
- Blow: Very strong blow, rising in a single thick column, 6-12m height.
- Head: Forms less than a quarter of total length. Broad, flattened rostrum forming a U-shape. A single raised ridge runs from almost the tip of the rostrum to the splash-guard around the blowhole. This splashguard is very prominent.
- Dorsal Fin: Tiny, low triangular fin. About 30cm high, set three quarters of the way back along the body (may not be visible from a distance).
- Colouration: Blue-grey, mottled with grey, white or silvery patches. Flipper tips and undersides lighter. The blue colour varies among individuals but may also darken with age.
- Blue Whales break the surface with a massive blow of c10 metres high. The rostrum (flat area in front of the splash guard) is flat and rarely breaks the surface. The enormous splash- guard protrudes high out of the water. The small dorsal fin is not always visible on surfacing, as some individuals are so long that they are below the surface by the time the dorsal fin passes. The region behind the head is extraordinarily wide and the spine appears like a massive muscular column down a broad rotund back. Their sleek bodies may give rise to under-estimation of their huge size. Tail flukes are wide and triangular, with a slight caudal notch in the centre.
Source: Irish Whale and Dolphin Group
Habitat
Generally a species of water depths between 100 and 1000 meters.
Source: Harris S., Yalden D.W. 2008.
Habitats;
- Marine water body (M)
Sources: Harris S.,Yalden D.W., 2008; Fossitt, J.A., 2001.
Reproduction
- Estimated average lifespan:30 years
- Estimated age at sexual maturity: 8-10 years.
- Mating: Autumn-Winter (possiby off north West coast of Africa for North Atlantic population).
- Gestation: 11-12 months.
- Calving: Autumn-Winter
Threats faced
| THREAT | ARTICLE 17 THREAT CODE | RANKING |
| Seismic exploration, explosions | H06.05 | Medium |
| Fishing and harvesting aquatic resources* | F02 | Low |
| Death or injury by collision | G05.11 | Low |
| Noise nuisance, noise pollution | H06.01 | Low |
| Changes in abiotic conditions | M01 | Low |
*This would include the threat to this species of a reduction in prey availability as well as the threat of becoming by-catch / accidental catch 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 may be relevant in Irish waters.
Source: Source: IUCN SSC Cetacean Specialist Group 2007.
The 2008 Global IUCN Red List assessment for the species includes as a threat;
- Habitat shift as a result of Climate Change.
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.
Apart from an acknowledgement of the existence of legislative protection, there are no suggested Conservation Actions in the 2007 European Regional IUCN Red List assessment or the 2008 Global IUCN Red List assessment for this species that may be relevant in Irish waters.
Source: IUCN SSC Cetacean Specialist Group2007.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)
Worldwide in warm temperate to tropical waters with seasonal forays into cold temperate and polar waters.
Source: Harris S., Yalden D.W. 2008.
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
Once relatively common in Irish waters, 98 animals were landed between 1908-1914 and 27 between 1920-1922 at the Blacksod Whaling Station in Co. Mayo. Although much rarer now, there have been a number of sighting off the Irish west coast in recent years. Research, using US Navy underwater recording equipment has detected Blue Whale mating calls off the west and north-west coasts. This indicates that an estimated 30-50 may pass through Irish waters each year.
A single animal was sighted by researchers from UCC in the Rockall Trough in 2001. More recently two animals were recorded feeding among Fin Whales along the shelf slopes, off the Southwest coast in September 2008. Another Blue Whale pair was observed in Sept 2012 off the Porcupine Seabight in the Southwest in September 2012.
Source: Irish Whale and Dolphin Group.
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 Blue Whale 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
DEHLG 2009 Conservation Plan for Cetaceans in Irish waters.
de Klem, Cyrille, 1994. ‘The Problem of Migratory Species in International Law’, in Helge Ole Bergesen and Georg Parmann (eds.), Green Globe Yearbook ofInternational Co-operation on Environment and Development 1994(Oxford: Oxford University Press), 67–77.
Fossitt, J.A. (2001) A Guide to Habitats in Ireland. The Heritage Council
Harris S., Yalden D.W. (2008). Mammals of the British Isles :Handbook, 4th Edition. The Mammal Society.
IUCN SSC Cetacean Specialist Group; regional assessment by European Mammal Assessment team 2007. Balaenoptera musculus. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 15 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
Reilly, S.B., Bannister, J.L., Best, P.B., Brown, M., Brownell Jr., R.L., Butterworth, D.S., Clapham, P.J., Cooke, J., Donovan, G.P., Urbán, J. & Zerbini, A.N. 2008. Balaenoptera musculus. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 15 October 2014.
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.