With shovels in hand, Sapphire Coast Wilderness Oysters (SCWO) farmers and Shoalhaven Riverwatch took to the banks of the Yowaka River on May 8-9 for a two-day “sand sausage” working bee to combat erosion.
As part of the oyster farmers’ Environmental Management Systems (EMS) project, they identify problem areas and work alongside other organisations and council to mitigate impacts on the environment.
EMS coordinator Jilian Keating said the Yowaka River in Pambula was identified as a hot spot for erosion.
“Erosion impacts on oysters because it is basically releasing sediment and nutrients that can be attached to the sediment into the estuary,” she said.
Erosion impacts all kinds of marine biodiversity, and Ms Keating said it is most serious for oyster farmers of the Sapphire Coast as oysters are filter feeders – “the canaries of our estuaries”.
The land owners situated on Yowaka River told Ms Keating “metres and metres of bank has been lost over the past 20 to 30 years”.
SCWO admired the innovative solution from Shoalhaven Riverwatch, and invited members to test the sand sausage for the first time outside of the Shoalhaven.
Local oyster farmers and 16 volunteers from Shoalhaven Riverwatch joined forces to build supersized sand sausages made from ply board and steel frames filled with sand and held together by a robust geofabric.
The group accomplished two 50-metre sand sausages “in half a day’s work” Riverwatch member Bruce Walter said.
“The group cohesion and friendly banter really helps with the laboursome work.”
“We are always taking the mickey out of each other which makes the job fun,” he said.
Mr Walter said most Riverwatch members are retirees and the labour can be daunting at a glance.
“This is different to methods such as sand bagging, you don’t have to lift 30 kilo sand bags. It’s very easy work and oldies can do it,” he said.
The group shoveled an impressive 30.8 tonnes of sand in four hours. Riverwatch members said the total cost of the construction cost $200 compared to the equivalent of 50 sandbags at $800.
Although the award winning innovation is a temporary fix, Mr Walter said re-vegetation is an important action to follow.
“This is only effective if you do the remedial work after. The sand sausages stabilise the banks so that you can plant casuarina trees and mangroves to prevent erosion in the future,” he said.
Riverwatch member Margie Jirgens said the sand sausages are not only helping the oyster farmers, but making a difference to the environment.
“Clean water is everyone's problem, the oyster farmers measure the water quality. None of us [Shoalhaven Riverwatch] are oyster farmers or do this for financial benefits – we are all retirees,” she said.
“We need everyone to see – what is our problem in the river and, what can we do about it?”
The sand sausage project has been funded by SCWO and South East Local Land Services through their “Cultivating a Sustainable Future for the Sapphire Coast Oyster Industry” project.
The group finished off their working bee with an oyster tour of Pambula Estuary where they were shown the finer points of oyster farming by Brett Weingarth and sampled the produce.