Projects - Info & Background
The Estuary Care Foundation was involved in a range of projects from 2006 to 2023:
Restore the native oyster to the Port River and restore shellfish reefs
The Port River was, and is now, home to multitudes of shellfish. While shellfish were once food, they are now environmental agents.
Native oysters used to grow in oyster beds in the Inner Harbour. So, we’re returning the native oyster to the Port and providing the substrate they need for their subtidal reefs. They’re working too, with each native oyster cleaning a bathtub of water a day.
Our feral mussels and oysters are also water filters and can combine into multi-species reefs that can protect our shorelines.
Shellfish such as oysters, mussels and razor fish, are filter feeders – they ‘sieve’ their food from the water. As natural ‘water filters’, they provide a wonderful ‘ecological service’ - helping clean up waterways.
Shellfish reefs are also important in protecting shorelines, especially as they are challenged by sea level rise. Reefs lock-up carbon and provide a foundation for a network (or eco-system) of other marine life.
While the Port River and Barker Inlet Estuary is home to numerous shellfish, the once plentiful native flat oyster, Ostrea angasi, has been classified as “functionally extinct’ not only in the Port River but throughout South Australia.
Restoring Ostrea angasi to the ecosystem and providing substrate for existing shellfish, will improve water quality, help stabilise shorelines, and enhance the ecology of the estuary.
Our project in the Port River was the first local, citizen science, shellfish restoration project in SA.
Volunteers first met in January 2016 to devise and undertake the Port River Shellfish Restoration Project.
We were part of broader efforts to restore shellfish reefs, which once existed along 1,600 kms of the South Australian coastline.
Our main strategies were to:
• Restore the native oyster Ostrea angasi to the Port River
• Provide substrate for multi-species reefs and native oyster stock to colonise the reefs
There was a lot of research and exploration in the project, because it hadn’t been attempted here before. So, we learnt and experimented, revised and documented our efforts.Our project was part of the national Shellfish Reef Restoration network and benefited from advice and support through the network. The project included volunteers of the Foundation and from PAREPG, the SA Malacological Society and the Marine Life Society.
Latest Shellfish Restoration News
Offer an environmentally friendly alternative, or addition, to seawalls
With rising sea levels and fiercer storms, and our low-lying land along the River, more structures for protection of homes, businesses and public infrastructure will be needed.
Living Shorelines along the River could include rocks, mangroves, samphires, seagrasses and shellfish reefs.
Living Shorelines can be more cost effective than hard structures e.g. seawalls, while providing the beauty and benefits of habitat.
Port Adelaide and the Lefevre Peninsula are experiencing sea level rise, land subsidence, tilting and erosion along the Port River. That all contributes to the area being one of the most vulnerable in SA to flooding and inundation.
Tide gauging in the Western Adelaide region has found sea levels in 2014 to be rising at a rate of 2.06 millimetres per year and 2.08 millimetres per year at the Inner Harbour and Outer Harbour areas respectively.
Sea level rise could exacerbate exposure to non-climate specific threats such as land subsidence from natural causes and anthropogenic activities (e.g. landfill developments and large-scale groundwater extraction), and saline intrusion of aquifers.
Sea level rise is also expected to intensify storm surge events. These are events where sea levels rise significantly above normal tide levels for a temporary period of time. Under a high sea level rise scenario, storm surge events could cause tides to reach areas that are presently several metres above AHD.
AdaptWest, the Western Adelaide Region Climate Change Adaptation Plan, has identified the risks that we are seeking to address and the solutions that we are seeking to trial (i.e. Living Shorelines), amongst its Priority Adaptation Options.
While Living Shorelines have been implemented overseas for many years, the concept was not widely known in South Australia and there were no demonstration sites established in 2016, when ECF was formed.
A Living Shoreline strategy facilitates natural systems while providing improved protection (both engineered and natural). Climate change, including sea level rise and the potential increase in frequency and severity of storms, has placed an emphasis on shoreline protection. Unlike traditional means of shoreline armouring, such as rock walls and retaining walls, living shorelines offer a range of benefits well beyond erosion prevention and shoreline stabilisation.
Living shorelines use combinations of bio-engineered structures with elements of native aquatic plant and, and even animal, communities to provide the intended shoreline protection while also providing desirable green infrastructure and ecological benefits. They, like shellfish and seagrass restoration, help to counter the greenhouse effect by locking-up carbon in what is termed a ‘blue carbon ecosystem’.
ECF sought to act on the risks and recommendations of AdaptWest by designing and constructing trial Living Shorelines.
Given the risks, from adverse weather events and flooding, to existing and proposed homes around the Inner Harbour, this was a priority area for Living Shorelines.
For information and updates on progress, see the Posts for Living Shorelines.
Latest Living Shorelines News
Monitor seagrass health and distribution and support its return
The seagrasses Zostera and Posidonia have survived in the Port River and Barker Inlet, though their health and range were severely impacted by past pollution.
Significantly improved water quality and Zostera achieving some natural restoration provides tangible signs of the River healing. Zostera is not without threats, including climate change, so its status needs ongoing monitoring. Trials can also support its return to our shorelines.
Seagrasses provide breeding areas for fish and crustaceans; they improve water quality and stabilise sediments (shorelines in the River) lessening the effects of wave action.
Seagrasses protect coastal infrastructure through wave reduction and retention of sediment, provide habitat for important fisheries, and are carbon sinks.
Seagrass meadows are an important component of the near shore marine environment of the Adelaide metropolitan area of Gulf St Vincent, where there are extensive subtidal beds of Posidonia (Tape weed), and Amphibolis (Wire weed). There are also extensive areas of Zostera (Eel grass) on the muddy banks adjacent to the mangroves in Barker Inlet and to the north, which also extend into the subtidal zone.
There has been extensive loss of seagrasses in the metropolitan region with significant changes to the marine ecology of the region. Restoring the natural seagrass beds will have major environmental benefits.
Of most interest to the Estuary Care Foundation were the intertidal and subtidal Zostera beds which, would have previously occurred throughout the Port River and Barker Inlet.
Improvements in water quality in the Port River and Barker Inlet enabled the natural restoration of Zostera and encouraged restoration trials by the Foundation.
Qualitative observations by Assoc Professor Jason Tanner, SARDI in January 2017 indicated that Zostera had extended its range in the Port River, south of the Quarantine Station. He observed a thick band of intertidal seagrass almost all the way to AGL, and a few small patches in between the 2 AGL cooling water intakes. There was little seagrass on the mainland side, just a small pocket at Mutton Cove, which was then thick and healthy.
This significant news encouraged the Foundation to establish seagrass monitoring and restoration trials.
For information and updates on progress, see the Posts for Seagrass Restoration.
Latest Seagrass Restoration News
Engage the community with the Port River and Barker Inlet Estuary; it’s worthy of understanding and support
The Port River and Barker Inlet Estuary is an important area for research, education and recreation. Through the arts, community education and events, the ecology and natural and Kaurna histories of the Estuary are better understood and celebrated.
The Estuary Care Foundation was one of many stakeholders involved with the Port River and Barker Inlet Estuary, and its restoration; collaborating with many partners including volunteers, community organisations, universities, schools, businesses and government.
The Foundation attracted volunteers to its organisation and enjoyed the support of members of other community organisations.
Activities of the Foundation, while community led, were informed by researchers and specialists who kindly made their expertise available to the Foundation.
Valuable expertise came from community members who belong to organisations such as the Malacological Society and the Marine Life Society.
The Foundation sought to profile the research, in the Port River and Barker Inlet, of our universities and research organisations.
The Foundation wanted to partner with research organisations to investigate:
• Nature-based solutions to climate change
• Monitoring of key species including shellfish, fish, shorebirds, seagrasses, and mangroves
• Carbon sequestration from mangroves, shellfish, and seagrasses
• Filtering and reduction of stormwater to the Port River and broader Estuary
The Foundation developed and promoted project outlines for research and sought interest in:
Thesis Proposal: Determination of Heavy Metals in Port River Bivalves, prepared by Michael Burrell, President, Malacological Society SA
The Foundation engaged the community in understanding the Estuary as a living system.
Several high schools participated in the Port River Shellfish Restoration Project and the Foundation engaged with schools and university students around the health and beauty of the Estuary.
The Foundation provided public speakers and organised public fora, walking tours, History Festival and Nature Festival events.
Public meetings were organised with international and national speakers on topics including coastal and aquatic restoration.
The arts can provide visual, sound, physical and other representations of nature, its challenges and restoration.
The Foundation collaborated with local artists around the themes of our projects and welcomed opportunities for engagement.
For information and updates on progress, see the Posts for Community Engagement.