Nature's nurture to help for shore

Friday, 1 June 2018

In the small coastal town of Portarlington, an innovative approach is being trialled to combat foreshore erosion.

Traditional engineering techniques such as rock seawalls and groynes have been bypassed in favour of an exciting new 'soft' engineering solution.

Significant sand loss along Ramblers Road foreshore, near Portarlington, is being addressed by the construction of an offshore shellfish reef designed to reduce wave energy and erosion and possibly even help reclaim parts of the foreshore.

Shellfish reefs were once spread throughout Port Phillip Bay and naturally protected our coastline. Changes to environmental conditions and the impacts of intense harvesting have resulted in a dramatic decline in the number and size of shellfish reefs.

The City is managing the engineering of the reef structure and we're partnering with the University of Melbourne to monitor the project.

Initially constructed on land, the reef is a series of 1.25 metre-high steel cages filled with rock and shell that are then transported from land by barge to construct a 130-metre-long reef. Part of the reef will be 'greened' by seeding some cages with tiny young shellfish, known as mussel spat.

The reef should require minimal maintenance and marine life, including a range of macro algae, invertebrates and shell fish, are expected to colonise the structure.

The project has attracted the interest of coastal managers around Australia following recent presentations at the Australian Coastal Councils Association and the National Climate Adaptation Conference. Many coastal managers are keen to learn to more about the technique and its potential to save costs and prevent environmental damage experienced with traditional engineering erosion prevention strategies, such as building rock seawalls and groynes.

The Ramblers Road shellfish reef project is contributing to a clever and creative future.