Reviving Coffin Bay’s Lost Oyster Reefs

South Australia’s first community-driven marine-restoration project.

Our mission is to revive Coffin Bay’s world famous native oyster reefs and the ecosystems dependent upon them.

Coffin Bay was once home to some of the largest oyster reefs in southern Australia, but this vital habitat was lost to a historical oyster fishery.

Now we have the tools and to right that critical wrong.

Project Outline

Step 1 - Engage with Community (Ongoing)

First, we needed to determine whether or not the local community would be interested in having these reefs restored, and whether or not they’d like to help.

so far, community response has been nothing but positive! we’ll continue to develop relationships and connect with community.

Step 2 - Collect the data (Ongoing)

We’ll be placing sediment panels in various sections of coffin bay, kellidie bay, douglas bay, and dutton bay, during oyster spawning periods to survey oyster population growth.

we’ll also be diving around our estuaries and conducting fish-count, invertabrate, and crustacean surveys.

Step 3 - Analyze the data

we’ll use this data to decide where the best place to install new reef substrate, and how large these reefs are going to be.

Step 4 - Build the reefs

We’ll be placing spent oyster shell into biodegradable mesh bags, which will be the building blocks for our reefs.

local oyster producer - coffin bay oyster farm - has come on board to donate their spent shell. thanks heaps you legends!

Step 5 - Deploy the Reefs

Once the shell bags are constructed, we will go to the site that we’ve selected and place the bags on the seafloor.

As the shell bags have a bit of weight to them, they will stay secured to the bottom.

These bags dissolve in 3-5 years. once the bags dissolve, new oyster growth will cement the bags together and keep them in place.

Step 6 - Monitor the Reefs

We’ll be diving these reefs regularly, making sure that intrusive turfing algae won’t smother the fresh substrate.

While underwater, we’ll take hundreds of photos, and reconstruct 3d models of the reefs regularly to observe change over time. (Structure from motion photogrammetry)

Step 7 - Publish Data

With all of this data we collect, we plan to publish scientific articles about our findings, our community, and the positive impact that these reefs can make.

We aim to have this project completed by the end of August 2026. By then, we will be able to understand the short-term impact of building these reefs, and hopefully continue this project on a larger scale.

Become an eyrelab member to get involved and make history.