RECYCLED oyster shells are being used by marine biologist and Fisho contributor Dr Ben Diggles, along with traditional owners, to try and restore the biodiversity and water quality of Moreton Bay in South East Queensland.
Moreton Bay’s oyster industry became unviable 20 years ago, but Australia still has a huge appetite for them. As a result, in the town of Ningi, shell waste from New South Wales, Tasmanian and South Australian oysters is being recycled.
In the Pumicestone Shellfish Reef Restoration project, an OzFish initiative, recycled shells from a local wholesaler are sterilised for four months to prevent the introduction of pests and diseases before they are reintroduced into the estuary as restored reef substrate.
It is a project combining traditional knowledge and modern science that could one day dramatically improve the health of Australia’s coastal waters. Devastating floods 120 years ago after mass land clearing in the region smothered the bay’s over-exploited reefs with mud, eventually leading to habitat extinction. Last year, trial oyster reefs made of recycled shells were sunk in Pumicestone Passage, a narrow waterway between the Queensland mainland and Bribie Island, to see if it was possible to re-establish them in coastal waters. Almost 12 months on, there is some evidence it is working.
Underwater footage shows once barren and silted mudflats now have new life. Three meters down, the artificial reef is teaming with fish and baby oysters have started growing on the recycled shells.
“The number of oyster spats we have on these shells shows the reef we are putting down could be self-reproducing, so it’s really great news,” Dr Diggles said while observing oyster shells brought up from the reef.
But these oysters are not for eating.
“No, these oysters are eco-system engineers, let’s not eat them,” he said. “We’ve lost the filter of our bay, we want to put the filter back in.”
You can read the full report HERE. Or, if you wish to initiate similar habitat restoration work in your region, go to the OzFish website.
