FROM DR CHARLOTTE JENKINS

Welcome to Bidhiinja (Bid-hin-jar) – Restoring our oyster reefs exhibition
This collaboration between the NSW Dept of Primary Industries and Regional Development and the Australian National Maritime Museum is about the plight of oyster reefs and the efforts being made with project partners to restore them. Our coastlines have not always looked the way they do today. Oyster reefs were once a dominant part of our seascape. No one alive today in Australia has seen the once-great expanse of thriving reefs. It has been estimated that more than 99% of our oyster reefs are now considered ‘functionally extinct’ – devastated by a  combination of overfishing, habitat destruction, catchment clearing and water-quality degradation, land reclamation and disease.
Whilst many people are familiar with coral reefs, mangrove forests and seagrass meadows –oyster reefs are a lesser known but equally important marine habitat. Oyster reefs are a complex ecosystem providing home to over 300 marine animals, such as shrimp, crabs, clams, snails, worms and many fish species. They provide water filtration properties through the oyster’s natural ability to filter feed.
For example, a wild adult Sydney rock oyster can filter upwards of 50L of water an hour – reefs are made of millions of individual oysters so just imagine for a moment, the filtering capacity of a reef ecosystem! Oyster Reefs also help to stabilise our shorelines, protecting our communities and coastal habitats from storms and waves.

The NSW Oyster Reef Restoration and Research Project, led by NSW DPIRD, helps to reintroduce oyster reef habitats to the state’s estuaries and the community and to share the story of their rich history, important cultural value and significant benefits to local communities and estuaries.
Small wild oyster populations still exist in some estuaries, but most were overharvested during the early colonial period. Oysters were a familiar and welcome food source for the European colonists but the unregulated, indiscriminate harvest resulted in the removal of all sizes of oysters to supply the colonists’ voracious appetite. 

Oysters didn’t only provide important sustenance for the colony. The colonists quickly realised that the extensive Aboriginal shell middens and the abundance of living oyster reefs could provide a source of lime for construction, to support the expanding colony. Aboriginal shell middens were plundered, whole living reef systems broken up, often by convict shell gangs, and shipped off to central lime kilns. Temporary kilns, constructed right on the riverbank, were used if local needs dictated. The lime created from the burnt shells and consolidated oyster reef was used for lime mortar – forming the foundations of the early colony. 

Catastrophic outbreaks of oyster pests and disease affected the populations that remained. The once extensive natural oyster reef system collapsed and has shown few signs of recovery. This collapse extends to the Clarence River which once had abundant natural oyster beds and later supported a strong oyster aquaculture industry. Now many areas of the Clarence River no longer support oysters even the aptly named “Oyster Channel” where oysters once thrived.

In 2019, the Department initiated a landmark project collaborating with project partners to restore started in Port Stephens and have since progressed to the award winning Wagonga Inlet Living Shoreline in Narooma. The project team is continuing to work with local partners and progress oyster reef restoration and research in NSW to revive this lost rich marine habitat and return the amazing benefits they can provide.