Project Description

Rainbow Wrack

Scientific name:  Cystoseira tamariscifolia
Size:  Up to 60cm long

Colour:  Green with characteristic blue-green iridescence
Habitat:  Found on both rocky and gravel shores, including rockpools.

  • Colourful iridescence when in the water – reflections of light that produce colours when viewed at different angles.
  • Iridescence produced by oil-based structures within the seaweed.
  • This iridescence responds to sunlight; lots of light causes the seaweed to breakdown the crystal structures, meaning less iridescence.