Seawalls

Seawalls are man made and built over rocky shores to protect the erosion of the shoreline.


  • Only 10% of Sydney Harbour's original shoreline remains.
  • Seawalls are part of our iconic landscape but compared to natural shores they are largely bare.
  • The number of seawalls built of concrete and sandstone, in coastal habitats, is increasing due to population growth and rising sea levels.
wall

Current Research

Previous research, carried out by Gee Chapman, former Director of the EICC, has shown it is possible to increase the number of plants and animals on a seawall by engineering crevices and spaces which protect organisms and retain water during low tide.

The McMahons Point shoreline is an example of a seawall that has been engineered to encourage increased plant and animal life. In this instance, the University of Sydney worked with North Sydney Council to design sandstone blocks with inlets acting as rock pools. They also drilled holes into the surface for animals and plants to find shelter in.

One such space was this man made rock carved into the wall which serves as protected area for organisms that otherwise wouldn't be able to live on the wall.

rock pool
starfish

Dr Mark Browne built on Gee's research by adding flowerpots, acting as rock pools at low tide, to seawalls at Cremorne Point and Careening Point in December 2008. One year on and he has seen a significant increase in the plant and animal life in the pots along the seawalls.

Mark is currently working with Boral and Blue Circle Cement, Antique Stone, ECS Services and North Sydney and Mosman Councils to test which concrete encourages the most animal and plant life.

inside
under

Active Researchers

  • Dr Mark Browne, EICC
  • Associate Professor Ross Coleman, EICC

*The seawalls study was initiated by Gee Chapman who has now retired from the University.

mark