It forms temperate seaweed forests that are important as habitat for many marine species and also for producing oxygen and capturing atmospheric carbon.

[3] The algae have a central main axis, usually up to 3 m (9.8 ft) long, which bear many branches along their length, with closely arranged, leaf-like laterals.

The strongly seasonal growth of the algae depends on the length of daylight; it occurs from apical cells and is restricted to the top 20–30 cm (7.9–11.8 in) of the branches.

[3] Crayweed forests are important as habitat for many marine species and also for producing oxygen and capturing atmospheric carbon.

[3] A conservation effort known as "Operation Crayweed" has been working to re-establish the species in the waters around Sydney.