Seals

Seals in the Atlantic

The Gray Seal

Halichoerus grypus 


Internationally, gray seals are protected by Appendix III of the Bern Convention and Appendix II of the Bonn Convention. This species is fully protected in France by Appendix II and V of the Habitats-Fauna-Flora Directive. It is therefore of high heritage interest.

According to the IUCN, the species is classified as Least Concern, so it is not internationally threatened. However, due to these low numbers in France, this species is “said” to be vulnerable. The world population of the species of H. grypus today stands at 300,000 individuals, compared to 50,000 in 1960. Their demography has been constantly increasing for about forty years, especially since the species has benefited from legal protection. The population living in the East Atlantic is estimated at 150,000, of which between 109,000 and 125,000 are around the British Isles. This represents 40% of the world's population. The French coasts are home to around a hundred gray seals (between 100 and 150), mainly located in Brittany.
Indeed, 45 individuals live on the Molène archipelago and 20 in the Sept-Îles archipelago. In addition, groups of individuals seem to have been permanent since 1994 off Normandy, on the Ecréhous and on the Minquiers archipelago, with a maximum of 18 individuals recorded in 1981. Births amounting to between 6 and 7 per year on these islands, French gray seal populations are increasing slowly but steadily. Although few individuals live in the Gulf of Biscay, the gray seal has permanent status in this area. These are the southernmost representative individuals of populations located mainly in the Channel - North Sea region.
Common, quite common
Rare, very rare or localized
In France, a large part of the individuals are located in the English Channel, but they are also found all along the Atlantic coast in the Bay of Biscay. The estimated number of individuals in French waters is 400 - 550 individuals.
Worldwide protection status
National protection status

The Harbor Seal

Phoca veal
The harbor seal, belonging to the Phocidae family, is a so-called non-threatened species according to the IUCN red list at the global level. In effect Phoca vitulina is a medium-sized population but benefits from the protection status of the Bern International Convention of 1979 (Appendix III). The global estimate is approximately 610,000-640,000 individuals, divided into 5 different subspecies depending on their location. In the North East Atlantic, we find the subspecies Phoca vitulina vitulina .

In France, this subspecies has the status of marine mammal protected at the national level by Annex II and V of the Habitats-Fauna-Flora Directive, and is qualified as an endangered population by the criteria of the IUCN.

In the mid-1980s, there were 98,000 harbor seals in the eastern Atlantic. By then, populations had recovered after sometimes intensive hunting and population control programs. In 1988, there was a significant mortality of this species following a viral epidemic: there was a drop of up to 50% in the population within certain groups in the south-east of Great Britain.
But the populations affected by this high mortality managed to recover quickly after the epidemic. The current number of individuals is estimated at 83,000 in a study dating from 2010. The IUCN took its data, compiled them with other studies and updated this number by estimating it at 65,000 mature individuals. in the Eastern Atlantic in 2016. The current population trend is currently unknown because it is not classified as threatened by the IUCN Red List, so few studies have been carried out on this species. In France, a large part of the individuals are located in the English Channel, but they are also found all along the Atlantic coast in the Bay of Biscay. The estimated number of individuals in French waters is 400 - 550 individuals.
The size of these populations fluctuates enormously for natural but also anthropogenic reasons. In general, today's seal populations are currently protected from hunting. But at the time in the Eastern Atlantic, many population control programs in the 1980s and 1990s took place in Iceland and Scotland, which continue to some extent even today. There were even extermination programs at the beginning of the 20th century, which greatly reduced the population of Phoca vitulina vitulina , in the Baltic Sea. In Norway there are even quotas for harbor seals.

Worldwide protection status
National protection status

The threats

Since seals regularly find themselves on the coast, they are subject to anthropogenic threats from humans with whom they are forced to share their resting areas. Therefore on the coast, they are exposed to wild terrestrial carnivores, domestic animals and wild animals and waste from human populations which increase the risk of exposure to communicable diseases. Since many harbor seals live and feed close to large human populations, they are also exposed to high levels of industrial and agricultural pollutants (Organochlorines, PCBs, dioxins) which can harm reproduction, induce a deficiency in vitamin or cause immunosuppression.

These spills can have long-term impacts on the health of seals and their environment. The general problem of pollution from military, agricultural and/or industrial activities (including coastal and offshore oil and gas development) is of particular concern due to its direct and indirect effects on seals and the food they consume. Additionally major disease outbreaks may have been intensified due to suppressed immune responses caused by a variety of pollutants. The seal has to deal with other disturbances such as noise, as well as the development of offshore renewable energy such as wind farms, which can also affect the feeding behavior and physical condition of individuals. The modification of the environment of these populations also leads to inter-species competition such as between the harbor seal and the gray seal, two species found on the French coasts. We also note that many individuals find themselves trapped by human fishing techniques. Overfishing of seal prey also leads to a net decrease in available resources, directly affecting populations. Climate change also affects these populations. Development projects can alter or eliminate important habitat or displace seals by increasing disturbance near haulouts.
Study carried out by our two interns: Pauline SILORET and Eloïse DETREZ
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