An initiative of Earthwatch Institute

  1. Velvet1_amber-louise_burberry Up to 30cm in length by AL Burberry
  2. Velvet4_amber-louise_burberry Velvet weed floating attached to hard substrate underwater by AL Burberry

Velvet Weed

Codium fragile


  • Velvet weed is a small green seaweed. 
  • It has dark round, dark forked fronds (branches) with a fuzzy appearance.
  • It has a velvety or sponged texture. 
  • Size up to 30cm in length. 


What to Observe

Search area for 30 minutes and record under the following categories:

  • Abundant - found easily with little searching
  • Frequent - found with minimal searching
  • Rare - only 1 or 2 individuals found with intensive searching
  • Not found - not present during search

ClimateWatch Science Advisor

As a result of climate change, warm tropical ocean currents are expected to strengthen and persist for longer periods in southern coastal area normally dominated by cooler waters. The consequent increases in water temperature are likely to result in unfavourable growing conditions for cool water algae species, causing a loss of seaweed in some areas.

Where To Look

Throughout the year.

Velvet Weed distribution map - GBIF

Velvet Weed distribution map - GBIF



Edger, GJ. (2008). Australian Marine Life. The Plants and Animals of Temperate Waters [2nd Ed]. New Holland Publishers Australia Pty Ltd.


  1. Search Species

  1. What Else?

    There are several other similar Codium species resembling Codium fragile. Velvet weed can usually be distinguished from these by having a dark green, rather than light green appearance, a tubular rather than flat cross section and furry appearance.  

  1. Did You Know?

    A sub species, Codium fragile tomentosoides, is highly invasive.