Huon Mundy Oyster Reefs

Noosa, Queensland, Australia

Constructing reefs in an ecological heritage site and urban estuarine environment. Prior to European settlement, the Noosa River estuary was once dominated by rock oyster beds, which provided important ecological services to the river and served as an important food source for First Nations groups for millennia. However, excessive harvesting resulted in the loss of the vast majority of the oyster habitat, leaving a void in both the river’s ecosystem and cultural heritage. The Noosa Oyster Ecosystem Restoration Project, a partnership project between The Nature Conservancy (TNC), Noosa Shire Council, The Thomas Foundation, and the Australian Government, was created to restore the rock oyster beds and their ecological services to the river and to help stabilize the riverbank against erosion from recreational boat wakes. In 2022, 30 reef patches were installed at four sites throughout the river before volunteer groups seeded the sites with 600,000 juvenile oysters. The reefs were designed to replicate the complex habitat of the historical oyster reef beds while fitting in with the modern environmental condition of the Noosa River, which now hosts a wide range of human uses and urban development. Following construction, Noosa’s traditional custodians, the Kabi Nation, named the reefs the Huon Mundy Reefs after a great Kabi spiritual leader.

Article Cover and above: The Huon Mundy Reefs are located within a narrow area of Noosa River Estuary near to existing habitat and the developed tourist town of Noosa. The reefs have reduced the level of wave energy impacting the foreshore of the river, which has led to accretion of sediments along the foreshore and the establishment of seagrasses between some of the reef patches.

(Photo by Richard Howard, Noosa Integrated Catchment Association)

Producing Efficiencies

TNC created a restoration suitability model to select the best locations to restore oyster habitat, considering a range of ecological criteria. The reefs, designed by International Coastal Management, primarily operate as effective substrate for the restoration of the oyster ecosystem and protect the riverbank from wind and boat-wake-generated wave energy. The shape and size of the oyster reef patches were designed to provide the greatest environmental outcomes and reflect the bathymetry at each site, minimizing impacts to coastal processes and existing sensitive marine habitats. Each patch was strategically located to ensure public access and public safety. Comprehensive design requirements guided the design of each reef patch, allowing for flexible adaptation of reef patches during construction.

Using Natural Processes

Oysters offer powerful natural processes to estuarine environments by filtering large volumes of water, providing structure for marine species, and dissipating wave energy. The Huon Mundy Reefs offer shoreline protection and promote sediment accretion along the shorelines behind the reef patches. In time, with establishment of the oyster ecosystem, the new reef structure, grown by the oysters and other shellfish, will provide further stability and resilience to the riverbank and allow the reefs to adapt to changes in water level and respond to climate change. The restored ecological processes are also expected to help reestablish other marine habitats within the estuary’s ecosystem.

New rock reef patches at the Noosa Sound West site, replacing the historical oyster beds that once dominated the estuary.

(Photo by Sam King, International Coastal Management)

Broadening Benefits

The restored oyster reefs are an important component of the health of the Noosa estuary, creating complex habitat for fish and other marine species and improvements to estuarine water quality through filtration. In addition, the hard reef produced by the oysters and substrate provides great structure for reducing wave energy and stabilizing the shoreline. The reefs provide fishing, recreation, water-based ecotourism, and educational opportunities for the Noosa region, which is a popular tourism destination in Queensland. The restoration of the oyster reefs also represented a significant reconciliation step to renew the cultural links of the Kabi Kabi Traditional Owners to their sea country.

Submerged reef patches at high tide.

(Photo by Richard Howard, Noosa Integrated Catchment Association)

Promoting Collaboration

The project team consulted extensively with various interested parties, including the local Kabi Kabi Traditional Owners, local council and state agencies, local fishing industry representatives, community organizations, residents near the proposed reef sites, and the general public. Community participation was essential throughout, with volunteers assisting with “oyster gardening” and seeding of the reefs on completion. Involvement and collaboration with these groups and the local community was crucial to shaping the direction and outcomes of the project. A multidisciplinary approach brought together the collective expertise and resources of aquatic scientists, planners, coastal engineers, and volunteer groups.

The reefs were seeded with juvenile oysters. Ongoing monitoring preliminarily reports the establishment of a range of shellfish species.

(Photo by Craig Bohm, TNC)

“Oyster gardening” by local volunteers grew juvenile oysters on recycled oyster shell in the Noosa River.

(Photo by Klaus Horner TV Production)