The Wadden Sea, the habitat of the seal

In June 2009, the Wadden Sea was officially designated as UNESCO World Heritage site. At this time, 66% of the total Wadden area falls under the World Heritage site. The Wadden area is 400 km long and covers a surface of almost 10.000 km2. It consists of 280 km2 of saltmarsh (an area of vegetation that borders directly on the sea), 4.120 km2 of tidal mudflats, 2.325 km2 of flooded mudflats and gullies, and 240 km2 of islands and sandflats.

All of these gullies, mudflats and islands make the Wadden Sea unique. Thanks to the flow of seawater, the tides, the wind, and other forces of nature, the appearance of the Wadden Sea is constantly changing. On the other side of the barrier islands, there is almost 3.000 km of North Sea coastal area which is considered part of the area – just like parts of Germany and Denmark. All of this combined makes the Wadden Sea one of the largest intertidal areas in the world.

The seal in the Wadden Sea

The Wadden Sea is one of the few places in the Netherlands where you can see seals in their natural habitat. Sometimes you will find a seal swimming amidst the waves, other times you can encounter them hauled out in the sun or nursing pups on the sandflats. Currently, there are approximately 15.000 seals in the Netherlands – 8.200 common seals and 6.800 grey seals – of which over 90% live in the Wadden Sea and the rest reside in the Zeeuwse Delta. The entirety of the Wadden sea, which includes the German and Danish parts, counts approximately 27.000 common seals. Grey seals were absent for a very long time until they reappeared in the Wadden Sea in 1983. Now, there are over 9.000 grey seals in the entire Wadden Sea.

Because the Wadden Sea changes multiple times over the course of a day, seals are forced to adapt to a rapidly changing environment. Most of the resting areas that seals use, flood during high tide. In these periods, seals go to the North Sea to hunt for fish, cephalopods and crustaceans.

Waddenzee met rustende zeehonden
Resting seals on a sandflat in the Wadden Sea. Photo: Sergio Izquierdo Bloemen