An innovative trial using shellfish reefs to clean water in the Pine River is showing major promise for the health of waterways flowing past Brighton and into Bramble Bay.
Nature’s Cleaners at Work
The project, led by Unitywater in partnership with university researchers and conservation groups, is testing a nature-based solution to filter the water. Instead of chemicals, the trial uses shellfish, which are known as nature’s filters.
These reefs are not naturally grown. They are built using special baskets filled with recycled oyster shells. Volunteers help prepare the shells, which are sourced from restaurants. The shells are left in the sun for a year to clean them before they are placed in the river to attract young oysters, known as spat.
Once in the water, the growing oysters do their job. They filter the water for food, absorbing nutrients like nitrogen into their bodies. This process traps the nutrients, preventing them from flowing downstream and harming the marine environment.
Measuring the Early Success
Scientists are monitoring the reefs by testing the flesh of the shellfish and the sediment around them. The early results from the first six months are encouraging. The trial reefs have already removed over 7 kilograms of nitrogen from the waterway.
Researchers say these findings are significant. They suggest that a larger, scaled-up project could make a big difference. An area of reefs about the size of two football fields could potentially remove all the nitrogen from a wastewater plant that services 10,000 people.
This work is especially important because experts from the University of the Sunshine Coast note that Australia has lost more than 95 per cent of its natural shellfish reefs. This trial shows how restoration projects can help bring back the natural cleaning power of these oysters.
Photo Credit: Supplied
