The Wadden Sea is the largest unbroken system of intertidal sand and mud flats in the world.

The Zuiderzee was a shallow bay of the North Sea in the northwest of the Netherlands.

The North Sea is a marginal sea of the Atlantic Ocean.

The English Channel is a part of the Atlantic Ocean separating England from northern France and linking to the southern part of the North Sea.

The Irish Sea separates the islands of Ireland and Great Britain.

The Baltic Sea is home to more than 200 species of fish.