The lug­worm

The lugworm is one of the Wadden Sea’s best known creatures, but it isn’t easy to find. Its hallmark is the piles of sand it makes.

Lugworms are similar to earthworms and have an average lifespan of five years. They live in burrows in the sand of the tidal flats. The burrows are U-shaped and about 30 centimetres deep. By eating the sand of the North Sea tidal flats, they play an important role in the Wadden Sea ecosystem. In fact, every year they eat all the sand in the North Sea tidal flats down to a depth of 25 centimetres – and excrete it again. That’s where the distinctive sand piles come from that can be seen on the seabed at low tide.

The worms’ digestive activity supplies important nutrients to the surface and oxygen to the seabed. During the winter, the lugworm adjusts its body temperature to its surroundings so it needs very little energy and food, and it stays in its burrow where it’s protected from frost and cold.