Research shows hope for areas such as Port Fairy to stabilise beaches
Port Fairy residents knew they were in serious trouble when discarded household items started emerging from the dunes.
In 2012, trash began appearing on the beach as coastal erosion eroded the dunes and exposed an old garbage patch that had been buried long ago.
Port Fairy resident Nick Abbott remembers old refrigerators and appliances, bits of tin and lengths of cable turning up on the beach.
“Our concern was that we were seeing the tip of the iceberg and soon the beach would be filled with ugly trash,” he said.
The following year, Abbott joined other Port Fairy residents to measure the impact of erosion on local beaches using poles, ropes and laser levels. They started using drones in 2018, hoping to better understand the problem.
Due to the power of Southern Ocean waves and strong winds battering the coastline, Port Fairy in Victoria’s south-west remains highly vulnerable to coastal erosion, a problem that is accelerating with climate change.
While Port Fairy is among the areas hardest hit by sea level rise, new research focusing on a beach in Melbourne Bay provides a glimmer of hope. It shows that human intervention can help stabilize beaches in the face of coastal erosion, especially when these efforts are compatible with the natural marine environment.
At another Port Fairy beach, known as the night soil area, erosion debris included old toilet bins, some of which were rolling down the dunes. However, vegetation covers have since been installed to stabilize and encourage vegetation growth.
Blake Allan, scientific lead for Deakin University’s national coastal drone program, said the mat helped protect the ancient night soil area. However, erosion continued to erode the sand dunes near the old tip area. A rock wall installed in front of the old end protected part of the dune but deflected energy from the waves, causing aggressive erosion on both sides of the wall.
Allan also monitors the effects of coastal erosion in Port Fairy and provides data to policymakers.
“You can’t rely on memories. And we don’t want decisions to be based on a single event, because those knee-jerk reactions are really just a Band-Aid,” he said.
Recently published research by University of Melbourne coastal geomorphologist David Kennedy found that strategies to manage erosion at Sandringham in Port Phillip Bay have been largely successful over the past 20 years.
The peer-reviewed research was published at: Frontiers in Earth Science magazine examined the impact of man-made structures at Sandringham dating back more than 140 years.
Sea walls were originally built to prevent the cliff from being eroded. Kennedy said there were wild fluctuations in erosion at Sandringham in subsequent years until the 1990s, when the sand replenishment program began and the rate of erosion slowed.
In the 2000s, the installation of structures known as rock gullies, which extend into the water perpendicular to the shore, helped to further stabilize the beach.
“What we want to do with the ribs is keep the sand on that beach for longer, because over time it moves from south to north. All of the sand goes there. It all ends up in South Melbourne for decades,” he said.
Kennedy described the movement of sand as a natural phenomenon, but protecting beaches and the man-made structures behind them was part of the response to sea level rise and climate change.
“We don’t tend to think of landforms as dynamic systems. But I like to think of them like a dog’s tail; they’re constantly wagging.”
He said more recent human interventions at Sandringham showed it was possible to save beaches by working with nature rather than building rigid structures that risk increasing erosion.
Kennedy said places like Port Fairy, exposed to the raw power of the open ocean, would require a different management strategy to Sandringham. Loch Sport in East Gippsland, Inverloch on the Bass Coast and Silverleaves on Phillip Island are other places where coastal erosion is a serious problem for communities and the authorities who manage these natural areas.
“This is a world we have created that has been changed by humans,” Kennedy said. “We have to work with what nature has to offer to preserve the parts we love. If we don’t, we’ll be left with sea walls all along the way and no beaches.”
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Benjamin Preiss is regional editor of The Age. He was previously a state tour correspondent and also covered education for The Age.Connect with: excitement or email.
