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Dieren en planten

Mens en Milieu

Bladder wrack


5-15 centimeters long


round stem, flat branched side branches with bladders

  • Dut: Blaaswier
  • Lat: Fucus vesiculosus
  • Eng: Bladder wrack
  • Ger: Gemeiner Blasentang
  • Dan: Blæretang
Bladder wrack, Ecomare

Bladder wrack

Some seaweeds can have a greenish color, but yet are not green seaweeds. Bladder wrack is a good example. It can vary from olive-green to brown. Like all brown seaweeds, it is much sturdier than green seaweeds, which easily tear apart. Bladder wrack is easy to recognize by its bladders along the fronds. The floating bladders help the plant to stand straight up in the water. Bladder wrack grows along dikes, on wooden poles and on mud flats. It attaches itself to mussels, stones or other objects. It can grow up to 0.5 meters long. In earlier days, bladder wrack was used as a fertilizer as well as for a remedy for pain in the joints, swellings and skin diseases. Sometimes, there are no floating bladders and then it is easily confused with spiral wrack.

On Texel

, Ecomare, Salko de Wolf

Bladder wrack grows here in many places along the wadden dike and in the harbors. On the beach, there is almost always bladder wrack lying together with knotted wrack, but both of these come from plants growing in France or southern England. They are carried here with the dominating southwesterly sea currents. Should seaweed growing here break away, it would probably strand somewhere around Denmark.