More about bladder wrack

Close to the water surface

Bladder wrack is found along most coasts of the north Atlantic. The plants survive very well close to mean water level, where they are periodically covered by high water and left stranded at low. Bladder wrack is often found deeper than spiral wrack, but shallower than toothed wrack.
Where the difference between high and low water is great, bladder wrack can dominate an area that covers several metres on both sides of the mean water level. Along the Swedish west coast, where the difference between low and high tide is max. 20 cm, bladder wracks distribution vertically is very small. In the Baltic it is able to build wide belts, but these usually form downwards to deeper water from the mean water level. Possibly, it is the shortage of light that inhibits their distribution vertically in the Baltic, while it is competition from other algae that inhibits vertical distribution in Bohuslän on the Swedish west coast.

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Close to the water surface

Endures drought and cold

Home for many

Thread-like algae take over

Protect themselves with poison and mucus

Eggs and sperm at the top

Bladder wrack without bladders

Bladder wrack More facts Other names

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Bo Johannesson | Martin Larsvik | Lars-Ove Loo | Helena Samuelsson