Taxonomy
Phoca vitulina | Common Seal
Distribution
Status
Conservation status
| Range | Favourable |
| Population | Favourable |
| Habitat | Favourable |
| Future Prospects | Favourable |
| Overall Assessment of Conservation Status | Favourable |
| Overall Trend in Conservation Status | N/A |
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 II, Annex V
- Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention) Appendix III
- Wildlife Act (1976)
- Wildlife (Amendment) Act (2000)
- Wildlife (N.I.) Order of 1985.
Native status
Native.
Species Biology
Identification
The Common, or Harbour Seal (Phoca vitulina) is overall smaller than the Grey Seal (Halichoerus grypus) which also occurs around Irish coasts, and the very pronounced sexual dimorphism found in the Grey Seal is not seen in the Common Seal.
Average length for adult males is c.1.5 metres total length, for adult females c. 1.4 metres.
Average weight for adult males c. 90 kgs and for females c. 70 kgs.
Colouration is variable but generally consists of darker spots on a lighter ground colour.
Spots are smaller and more numerous than in the Grey Seal.
Spots may blend into larger patches dorsally, and individuals are paler ventrally.
When approaching moult, when coat is dry it can look brown or fawn.
Pups are only rarely born with a pure white coat unlike the Grey Seal.
The shape of the head and the shape and position of nostrils are perhaps best for distinguishing between the Common Seal (Phoca vitulina) and the Grey Seal (Halichoerus grypus) .
The Grey Seal has no major differentiation between a muzzle and forehead whereas in the Common Seal there is a noticable bridge between forehead and muzzle.
In the Grey Seal the nostrils are well separated and sub-parallel whereas in the Common Seal the nostrils form a vee shape, almost touching each other above the mouth.
Source: Harris S., Yalden D.W. 2008.
Habitat
This species forages at sea, but likely at closer proximity to 'haul-out' sites than is the case with the Grey Seal.
Particularly in the breeding season, but also at other times individuals of the species 'haul-out' onto land. Haul-out sites in the breeding season will most often be onto shores of islands or onto remote mainland shores.
'Haul-out' sites may be on rocky, shingle or sandy shores and even on grassland if it is within c.300ms of the sea.
This species is more likely than the Grey Seal to be found hauling-out onto inter-tidal habitats as even from only a few days old pups can dive for up to 2 minutes .When not breeding this species can be found close to centres of human activity if it is protected from human disturbance.
Source: Harris S., Yalden D.W. 2008.Habitats may include but are not necessarily limited to;
- Marine water body (M)
- Littoral (L)
- Salt marshes (CM)
- Brackish waters (CW)
- Shingle and gravel banks (CB)
Sources: Harris S.,Yalden D.W., 2008; Fossitt, J.A., 2001.
Reproduction
In Ireland, during the breeding season, the highest numbers of pups are born between June and July, and can swim and dive at just a few hours old.
Source: Lyons D. O. 2004
Typically, once a pup has been born (almost always females give birth to a single pup each year), the mother will mate once the pup has been weaned.
Implantation may be delayed for between five and twelve weeks and gestation lasts between eight and ten months.
Pups are weaned at after 3 to 4 weeks.
Males reach sexual maturity anywhere between four and six years, females between three and four years.
Females may live to 36 years males to 31 years.
Source: Harris S., Yalden D.W. 2008.
Threats faced
| THREAT | ARTICLE 17 THREAT CODE | RANKING |
| Fishing and harvesting aquatic resources* | F02 | Medium |
| Seismic exploration, explosions | H06.05 | Medium |
| Illegal taking / removal of marine fauna | F05 | Low |
| Marine water pollution | H03 | Low |
| Noise nuisance, noise pollution | H06.01 | Low |
| Changes in abiotic conditions | M01 | Low |
| Marine and Freshwater Aquaculture | F01 | Low |
| Outdoor sports and leisure activities, recreational activities | G01 | Low |
*This would include the threat to this species of becoming by-catch / accidental catch.
These threats accord well with the threats, relevant to the Irish population of this species, outlined in the 2007 European Regional IUCN Red List assessment for the species.
Source: European Mammal Assessment team 2007.
Conservation actions
In the Article 17 Habitats Directive reporting for the period 2007-2012, Conservation Measures implemented or being implemented were;
- Establishment of protected areas / sites (6.1)
- Legal protection of habitats and species (6.3)
- Regulation / Managment of fishery in marine and brackish systems (7.3)
- Regulating managing exploitation of natural resources on sea (9.2)
- Regulation / Management of hunting and taking (7.1)
There are no Conservation Actions in the 2007 European Regional, or 2008 Global, IUCN Red List assessment for this species that are not covered by the Habitats Directive Conservation Measures listed above.
Sources: European Mammal Assessment team 2007; Thompson, D. & Härkönen, T. (IUCN SSC Pinniped Specialist Group) 2008.
Distribution
World distribution(GBIF)
A northern hemisphere species. Populations known in coastal areas of eastern and western Pacific as well as coastal areas of eastern and western Atlantic.
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
Records from around the entire island but more records from western than eastern coasts.
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 BiodiversityData Centre is trying to improve our knowledge on the distribution of the Common, or Harbour Seal 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
European Mammal Assessment team 2007. Phoca vitulina. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 09 October 2014.
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.
Lyons D. O. (2004) Summary of National Parks & Wildlife Service surveys for common (harbour) seals (Phoca vitulina) and grey seals (Halichoerus grypus),1978 to 2003.Irish Wildlife Manuals, No. 13. National Parks & Wildlife Service,Department of Environment, Heritage and Local Governement. Dublin, Ireland
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.
Thompson, D. & Härkönen, T. (IUCN SSC Pinniped Specialist Group) 2008. Phoca vitulina. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 09 October 2014.