The Wadden Sea landscape

Glacial periods, meltwater, tidal waves and, eventually, humans have shaped the area that we know today as the Wadden Sea. It's a unique landscape.

The Wadden Sea is the area between the 23 Wadden Sea islands and the mainland. It stretches 500 kilometres from Blåvands Huk in Denmark to Den Helder in the Netherlands, and is the longest unbroken stretch of sand and mudflats in the world. The area was formed through a combination of glacial deposits, tidal waters, waves, mud, plants and an incredibly large amount of animal excreta. Only late in the history of the Wadden Sea did humans begin to interfere with the landscape in their quest for new land and protection from the sea.

First there was the ice

The early history of the Wadden Sea was characterised by the two last glacial periods, when huge ice sheets covered large parts of Northern Europe and altered the landscape around and beneath the ice. The earlier of these two glacial periods (Saale) peaked at around 140,000 years ago and covered large parts of Northern Europe. When the ice melted, it revealed the area that is now the Wadden Sea as a hilly landscape much akin to the type of landscape that is characteristic of Eastern Denmark today. The remainder of the hills from that time can be seen today as the elevated sections of land along the Wadden Sea; they are known locally as geest. The last glacial period (Weichsel) ended at around 11,500 years ago. However, during this glaciation the ice only reached up to around 80 kilometres east of the Wadden Sea area. Rivers of meltwater flowed from the ice sheet and made their way around the 'hill islands' 

bringing with them sand and gravel on their journey to the sea. The large amounts of sand and gravel settled as thick, smooth, westward-sloping blankets between the 'hill islands', turning the landscape into a flat plain.

The islands emerge

The ice retreated again and the sea started to rise. Around 8,000 years ago, the water had risen so much that the sea had become what we know today as the North Sea. Since this time, the tidal waters, the wind and the waves have formed the landscape. The North Sea moved the sand from the large meltwater rivers back towards the coast, where it settled as sand flats. However, over time the sand flats reached a height at which they were only flooded occasionally and, thus, the characteristic Wadden Sea landscape - the highsands - were formed. The islands were invaded by plants that could trap the drifting sand between their stems and, thus, the first sand hills were born, and thereby the Wadden Sea islands.

Animals and plants

During high tide, around 2 km3 of water washes through the Danish Wadden Sea. The water brings large amounts of sand and clay into the lagoons between the islands and the mainland where a small amount is deposited in the calm environment.

The mudflats are home to a myriad of bottom-living animals such as mussels and snails, which filter the water and clay particles in their search for food. The fine particles pass through the animals and come out the other end as larger particles. The coarse particles are not as easily moved around by waves and currents, so the animals are instrumental in supplying material to the mudflats.

The human factor

The lush marshland areas attracted humans early on, and they settled on higher-lying geests, where they were protected from flooding. For additional protection against the sea, the first dykes were established in the Tøndermarsken salt marsh in the Middle Ages. Today, the only marshland area that has not been protected with dykes is the marshland around Ho Bugt and in the Varde Å river valley. AS a result, most of the marshland areas are no longer subject to the natural mashland developments with regular flooding and supply of new material to the land. In step with technological development, humans began in earnest to change the landscape. The Grådyb channel near Esbjerg was made deeper and dams were established at Rømø and Sild. These infrastructure projects are examples of how humans have displaced the natural balance of erosion and deposition in the Wadden Sea. 


Guided tour

Go on a guided tour with one of the National Park’s experienced tour operators.

Varde

NaturKulturVarde

Roustvej 111, 6800 Varde

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  Obfuscated Email  +45 75 22 22 50

Club Fanø

Sønderklit 4a og Kirkevejen 37, Fanø Bad, 6720 Fanø

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  Obfuscated Email  +45 42 42 25 65

Fanø

Fanø Natur

Kallebjergvej 18 F, 6720 Fanø

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  Obfuscated Email  +45 28 57 07 61

Ribe

Vadehavscentret

Okholmvej 5, Vester Vedsted, 6760 Ribe

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  Obfuscated Email  +45 75 44 61 61

Mandø

Mandøbussen

Okholmvej 5, Mandø, 6760 Ribe

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  Obfuscated Email  +45 75 44 51 07

Bredebro

Vadehavssmedjen

Bunti 18, 6261 Bredebro

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  Obfuscated Email  +45 29 72 74 26

Højer

Scanoropa Bus

Torvet 1, 6280 Højer

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  Obfuscated Email  +45 24 25 09 89

Løgumkloster

Tønder egnens guider

Dravedvej 6 B, 6240 Løgumkloster

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Rømø

Naturcenter Tønnisgård

Havnebyvej 30, 6792 Rømø

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  Obfuscated Email  +45 74 75 52 57

Møgeltønder

Sort Safari

Slotsgaden 19, 6270 Tønder

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  Obfuscated Email  +45 73 72 64 00


Visit

If you want to learn more, visit one of the National Park’s exciting exhibition venues.

Blåvand

Blåvand Naturcenter

Fyrvej 81, 6857 Blåvand

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  Obfuscated Email  tel:+45 75 22 22 50

Varde

Varde Museum

Lundvej 4, 6800 Varde

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  Obfuscated Email  +45 75 22 08 77

Marbæk

Myrthue

Myrtuevej 39, 6710 Esbjerg V

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  Obfuscated Email  +45 76 16 81 00

Esbjerg

Fiskeri- og Søfartsmuseet

Tarphagevej 2 , 6710 Esbjerg V

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  Obfuscated Email  +45 76 12 20 00

Ribe

Vadehavscentret

Okholmvej 5, Vester Vedsted, 6760 Ribe

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  Obfuscated Email  +45 75 44 61 61

Rømø

Naturcenter Tønnisgård

Havnebyvej 30, 6792 Rømø

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  Obfuscated Email  +45 74 75 52 57

Højer

Højer Mølle

Møllegade 13, 6280 Højer

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  Obfuscated Email  +45 65 37 08 04