Ecomare

Grey seal

size:

Male: maximum 2.60 meters
Female: maximum 2 meters

weight:

Male: maximum 350 kilogram
Female: maximum 200 kilogram

color:

Dark grey with black spots. Females are lighter than males. Newly born have long grey hair.

age:

Maximum 50 years

food:

Particularly fish, but also shellfish and crustaceans, and occasionally a bird

movement:

Swimming and hobbling

enemies:

Humans (disturbance, hunting and by-catch in fykes and fishing nets)

reproduction:

Mature: between 3 to 8 years old
Pregnancy: 11 months
Birthing season: December/January

Dut: Grijze zeehond (kegelrob)
Eng: Grey seal
Fren: phoque gris
Ger: Kegelrobbe (Grauer Seehund)
Lat: Halichoerus grypus
Dan: Grisælen
Nor: Havert, Grisel

: Grey seal, Ecomare
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Grey seal

Grey seals are true sporters. They easily swim from the Wadden Sea to England and back again.They are less shy and much more curious than harbour seals. The pups are born in the middle of the winter on undisturbed sandbanks in the Wadden Sea. The vicious wind blows constantly in their faces but these tough young animals have a thick white winter coat during their first few weeks to protect them.

On Texel

Since 2000, a group of around 50 grey seals have been living on and around the western part of the Razende Bol (Noorderhaaks), a sandy island southwest of Texel. That's why this part of the island is now closed to the public.
Every winter, young grey seals are found along the coast of Texel. They are usually brought to Ecomare. Ecomare also has three grey seals in its permanent population.

Distribution and habitat
Distribution of the grey seal, Ecomare
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Grey seals live along the coasts of the Northern Atlantic Ocean. They can be found in the Baltic Sea, by Iceland, the Faroa Islands, Norway to Great Britain and by Northeastern Canada.

In the North Sea, most of the grey seals live around the Scottish islands, along the British coast and in Cornwall. This population represents 40% of the world population of grey seals and 95% of the European population. While there were around 30,000 grey seals in the whole of the North Sea in 1965, the population increased in the first decade of the 21st century to around 150,000. It grew particularly fast at the end of the 1970s when commercial hunting was banned.

In the Dutch Wadden Sea, there are two colonies on both sides of the sea channel to Terschelling and Vlieland. Since around 2000, there has also been a group of around 50 grey seals on the sand island Noorderhaaks, west of Texel. Grey seals are sometimes even spotted in the Zeeuws coastal area. And every once in a while, a grey seal is reported in fresh water.
Inland waters
Seals have no problem living in brackish or fresh water, as long as there is enough fish. Seals used to swim upriver more often. However, since most Dutch rivers are now shut off by sluices and dams, it's not that easy to reach inland waters anymore. Nevertheless, it still happens. Seals are regularly spotted in the closed freshwater IJsselmeer and in the major rivers. The most adventurous have even reached Maastricht. In order to achieve that, the animals must have slipped through sluices while boats were passing through or when the gates were slightly open. After a period of time, they swim back or let themselves flow back to sea when waterways are drained.

Photos and reports from eyewitnesses have shown us that grey seals have no problem finding food in inland waters. Every once in awhile, one is spotted with a large fish in its mouth. Strollers walking the 'jaagpad' trail from Middelburg to Vlissingen even witnessed a grey seal catching a swan and eating it up."The only thing remaining was a pile of feathers".

Large prey consumed above water is easy to witness. Smaller prey is more difficult, since they are swallowed under water. No one sees it happening. Up till now, it was unknown what grey seals eat in Dutch fresh water. However, a grey seal that washed ashore on the freshwater side of the Afsluitdike (Closure Dike) has helped to solve the riddle. While looking for the cause of death, scientists also looked at the stomach contents. They found seven different species of fish in the stomach and digestive system of the adult female. Perch, flounder, ruffe, zander and smelt were consumed the most. These are species were all caught in the IJsselmeer.
Population in the Netherlands
Development of the Dutch grey seal population, Ecomare
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The grey seal belongs to the original Dutch coastal fauna. Fossil finds have shown that the grey seal has lived here for a very long time. During the Middle Ages, the grey seal was annihilated in the Wadden Sea by the coastal inhabitants and until around 1980, this seal species became a rarity. Fortunately, it has recently returned. Because the grey seal started to get better protection in Great Britain, the population grew rapidly and the animals roamed to other parts of the North Sea and Wadden Sea.
In the Netherlands, the grey seal population is growing steadily. For example, in 1992 there were only 150 counted. In early 2003, there were more than 1000 adult animals. Strangely enough, scientists counted fewer grey seals in early 2007. The most plausible explanation is that they moved elsewhere, perhaps Helgoland where a new colony has developed. Growth continued in 2008 and 2009. In 2012, 3059 grey seals were counted in the Dutch wadden region.
Christmas kids
Grey seal pup., Ecomare
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Grey seals give birth during the middle of the winter. The pups have a white, long hairy pelt and weigh 10 to 20 kilograms. When they drink milk from their mother, they gain 1.5 to 2 kilograms per day! After birth, they must remain on dry land a few weeks until they shed their furry coat and build up their fat reserves. That isn't always easy. The sandbanks Richel and Noorderhaaks, where lots of Dutch grey seals are born, sometimes flood in the winter. That only happens during spring tide and flood, but during some winters the water rises so high that the young animals wash off the bank. They can be found spread out over the wadden coast and are then brought to the seal sanctuaries.

It seems that grey seals in the Wadden Sea are birthing earlier. The first pups are now often spotted in early December. Perhaps that comes from the increasing number of grey seals so that there are more older seals that begin earlier in the season. It could also come from climate change. There is still lots of research needed to establish the exact reason.
Protection
The grey seal is on the world conservation union IUCN's Red List for protected mammals. In addition, there are special reservations for grey seals. Two islands in the Orkney Archipel in the northern North Sea (Faray and Holm of Faray) were designated as Special Areas of Conservation (European Habitat Directive). This is where large well-established colonies of grey seals give birth to lots of young seals.
On 1 August 1999, the Scottish Wildlife Trust purchased the uninhabited island Linga Holm. This 56-hectare large island is home to a large colony of grey seals. The organization is hoping this island will become officially protected as well.
Flight elevations for grey seals
Because there are more and more grey seals living in the Dutch Wadden Sea, the number of pups born each season is also growing. During some years with high tides and storm, these young animals wash off of the sandbanks where they spend the first few weeks of their life. They lose track of their mother, and often end up in a seal sanctuary. Seal Sanctuary Lenie 't Hart in Pieterburen could hardly keep up with the stream of young seals that were washed away during the winter of 2006-2007. They had to build emergency accomodations and needed lots of extra funding.

Ecomare had a different plan: solve the problem at the source. Because of the need for undisturbed haul out areas, grey seals bring up their young on deserted sandbanks. The higher lying coasts in the wadden region, which are safer during storms, are often disturbed by humans. Simple regulations, such as placing screens made from reed branches, could help the sandbanks to grow higher and safer, serving as an effective flight hill for the grey seals.

The first natural flight hill has already been discovered by the seals themselves. Since the winter of 2007-2008, grey seals have been born on the island Griend. The island used to be difficult to get to for them. But now, a channel runs close to the island, which makes it easy for the seals to swim to during high tide. People are not allowed on Griend, making it an ideal dry and undisturbed flight hill for grey seals.