Port Phillip Bay

VICTORIA · CASE STUDY

From experimental reefs to a growing restoration programme

Port Phillip Bay’s shellfish restoration programme began with a practical question: how could native oysters and mussels be helped to survive and grow again? Trials developed into a series of reef-building projects, creating a valuable example of restoration that learns as it expands.

The challenge

Overexploitation, pollution, introduced species and disease contributed to the disappearance of the bay’s once-extensive oyster and mussel reefs. Losing these living structures also meant losing habitat for the many animals associated with them. ^[1]

Local knowledge helped start the work

The Albert Park Yachting and Angling Club’s account describes how members’ knowledge of the bay’s former shellfish habitat prompted an approach to Fisheries Victoria. The club, fisheries staff and The Nature Conservancy developed a working relationship that connected local interest with research, technical support and funding. The club’s role gives the project a community history as well as a construction timeline. ^[4]

In its 2024 account, the club reported raising more than $600,000 for shellfish restoration over more than a decade. That is a reported contribution by one partner, not the total cost of the bay-wide programme. It illustrates how recreational fishing organisations can help sustain restoration through fundraising and long-term involvement. ^[4]

How the reefs were rebuilt

The Nature Conservancy and partners began experimental work in 2015, followed by reef construction in 2017 and later expansions. Limestone and recycled shell provided foundations, while native Australian flat oysters and blue mussels were added to establish living reef communities. TNC’s project overview reports cumulative seeding of 13.5 million oysters and 2.7 million mussels. ^[1]

The Shuck Don’t Chuck programme connects restoration with local hospitality businesses. Used shells are collected, cured outdoors for at least six months, then used as reef material or as a surface for young oysters in hatchery tanks. Prepared shell carrying juvenile oysters can then be spread across the reef foundations. This gives discarded shells a useful second life in the bay. ^[2]

Matching construction to the seabed

A scientific assessment of early works describes the use of historical reef information, fisher interviews and diver surveys to select Margaret’s Reef and Wilson Spit. Oyster-bearing shell was spread by divers. Mussels could be delivered through a hose from a vessel using a purpose-built system. Monitoring compared restored and unrestored sites, with repeated surveys during 2017–2020. ^[5]

The distinction between an oyster and its supporting shell matters here. Clean recycled shell supplies a surface for settlement; the restoration animal is the native flat oyster. Material preparation, hatchery work and deployment are separate stages, each with its own role in getting living shellfish onto the reef. ^[2]

What monitoring has shown

The 2024 Reef Builder report recorded greater biodiversity on restored reefs than at soft-sediment reference sites. Recovery varied: very few mussels survived at Dromana, with predation by native eleven-arm seastars identified as a factor. These differences show why oyster and mussel outcomes need separate assessment. ^[3]

TNC’s project overview describes fish and invertebrate communities developing across restoration locations, including schools of juvenile fish at Dromana. Reported seeding totals represent animals introduced over time, rather than a count of the animals alive today. ^[1]

Restoration as a community activity

A related community shellfish reef initiative documented by Melbourne Water shows how this approach can be extended. In June 2021, catchment staff, OzFish and local fishers used a remotely operated vehicle to inspect the seabed for possible restoration sites. Its programme also set out activities involving fisher knowledge, on-water surveys and participation in restoration. ^[6]

Those community project plans should be distinguished from the completed works and monitoring results described above. Their relevance is the method of engagement: people who use the bay can contribute observations and help investigate suitable locations, while specialists assess whether a site can support the intended habitat. ^[6]

For another bay considering similar work, Port Phillip’s lesson is to connect local knowledge with an explicit monitoring plan. A promising location still needs baseline information, repeat surveys and a clear record of which species were introduced. Mixed oyster-and-mussel projects also need separate measures for each species, so success in one does not conceal a difficulty in the other.

The broader aim is a persistent habitat that supports marine life. A good assessment therefore asks how shellfish grow and survive, whether new animals settle naturally and how the associated community changes. Keeping those questions visible makes the programme useful to future projects, even where individual sites develop differently.

Sources and further reading

1. The Nature Conservancy — Port Phillip Bay

2. The Nature Conservancy — Shuck Don’t Chuck

3. The Nature Conservancy — 2024 Reef Builder Final Summary Report, pp. 26 and 28

4. Albert Park Yachting and Angling Club, via VRFish — Bringing a desert back to life (2024)

5. Bayraktarov and colleagues (2025) — ecological recovery of restored shellfish reefs

6. Melbourne Water — Port Phillip Community Shellfish Reef

Research checked 13 September 2026. Figures refer to the reporting periods identified above. Lessons are an editorial interpretation of the cited evidence.

Photo credit
Header photo: Jarrod Boord, Streamline Media. Cropped from Figure 2G in Bayraktarov et al. (2025). Licensed under CC BY 4.0.