Underwater Forests and Living Seawalls

Good as Cabbage Tree Bay is, imagine it even better. Manly's favourite snorkel spot will be part of a project to restore Sydney's lost underwater forests. It involves physically attaching starter crayweed colonies to bare rocks in the bay. The crayweed - a form of seaweed which once flourished along the Sydney coastline - has the potential to  re-invigorate the marine environment literally from the bottom up.

The project has been made possible thanks to the passion and generosity of local couple Dorset Sutton and Jenny Lim Sutton, and the creativity of scientists at Sydney Institute of Marine Science (SIMS). 

Jenny Lim and Dorset Sutton at Manly Community Forum.

The couple's philanthropy has a second focus too - transforming seawalls in Little Manly Cove into complex marine communities.  

SIMS Director Professor Peter Steinberg said 50% of Sydney's shoreline is built - mostly in the form of seawalls and jetties - creating an unnatural and difficult environment for sea creatures. 

The 'Lim-Sutton Initiative' means seawalls at Little Manly will be retrofitted with 'tiles' containing ribs and protrusions to mimic rocky shoreline habitats, and turning flat vertical surfaces into three-dimensional microhabitats for creatures as diverse as crabs, mussels, sea snails, sponges and algae. 

The 'living seawalls' can form the basis of an ecological community that supports marine plants, sponges, algae, molluscs, crustaceans and eventually healthy fish communities. 

"Jenny and I are thrilled to be able to help with these two great projects,” Mr Sutton said. “Restoring crayweed and naturalising the seawalls will boost the whole marine community and be a step towards getting these areas back to how they once were."

Professor Steinberg said both projects were part of larger endeavours.  He said crayweed (Phyllospora comosa) once formed 70km of underwater forests off Sydney's coast. The thick forests were killed off by water pollution during the 1980s, in an ecological tragedy that went unnoticed for almost 30 years. Now that our water is clean again, it's possible to bring them back. For more information and to help go to www.operationcrayweed.com

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