Old Dunsborough Beach
The original Safe Swimming Enclosure.
Working with the City of Busselton, we designed, supplied, and installed a shark barrier at Old Dunsborough Beach as a part of a state government trial.
The Brief
The City of Busselton is a popular holiday location in WA, and the council was looking to try a solution to keep swimmers safe from shark interactions at popular beaches. Initial quotes were outside the financial reach of the council, and they were looking for a solution that was both effective and within their budget.
The Solution
Paul and his team drew on their deep marine experience, and network of contacts within the marine industry to design a netted enclosure that would give the level of protection that the public deserved; be robust and resilient enough to withstand prevailing ocean conditions; and fit within the financial expectations of the council.
Installation Process
Whilst this was the first installation that Paul and his team had carried out, careful planning deemed it a success. The design of the 100m x 300m netted barrier, as well as the components chosen, made sure that the process was straightforward.
The Council had contracted the installation of the pilings out separately, and with these in place, it meant that the team of four was able to complete the installation of the barrier within two days.
Marine Environment Considerations
The ocean is constantly moving, and any structure installed within it needs to be both robust and flexible enough to withstand tidal movements, wave action, and storm surges. Additionally, the structure needs to allow for & accommodate the movement of seagrass wracks. In the case of the Dunsborough site, the sea grass moves in an easterly direction. Sea Grass wracks became repeatedly entangled in the net during windy or wavy periods. Initially, this required removal by inspection staff (simply lifting the net and allowing the weed to pass under), but the design was then modified to allow the longshore movement of the sea grass wracks to pass through unimpeded.
Success of the Trial
The trial period ran for four months (January to April) and was deemed a success across the following measures, as noted in the Review of the Dunsborough Beach Enclosure Trial:
“In terms of cost-effectiveness, one could argue that the beach enclosures provided guaranteed protection for those concerned by the risk of a shark attack occurring whilst also providing both peace of mind for those beach users and for those with environmental concerns regarding alternative programs that attempt to reduce shark populations.”
In summary, the project demonstrated that the design of the SSA barrier product was:
Cost effective upfront.
Resolved the issue of seagrass wrack release.
Low to moderate maintenance costs
Increased swimmer confidence
Additionally, it was noted that: “Ongoing management and maintenance costs for the system deployed at Dunsborough are considered low to moderate and favorable in comparison to other methods of shark risk mitigation”
But perhaps most important was the response of the public, particularly given that Dunsborough and the wider City of Busselton is such popular beachside tourist destination:
As soon as we saw the bay with the net we went in and enjoyed our swim so much having great peace of mind. It made a huge difference to our holiday in Dunsborough.
Review of the Dunsborough Beach Trial Enclosure