Building Reefs

We build new reefs from recycled bottles, to make a home for fish, organisms and our new corals.

We build sections of bottle reef, which in turn build larger reefs, such as step reefs and ribbon reefs. A bottle reef uses recycled glass bottles collected from the beach to create a 3D underwater structure. Small fish appreciate the vertical structure that lifts them away from the sand, crabs live within the cracks and crevices, and many organisms settle on the bottle surfaces. It also provides a platform for our coral growing.

Bottle Reef Basics

Bottles are planted in a concrete base and lowered onto the sea bed. They are secured to stop them moving away. Our coral growing project gives us a supply of new coral on small concrete tiles, called biscuits. These are wedged between the bottles. These corals slowly spread across the bottles and incorporate the bottles into the coral skeleton. The bottles slowly disappear and become the invisible reef skeleton.

Ribbon Reefs

Ribbon reefs are a line of recycled bottle reefs that join two places across an expanse of barren coral rubble.  They become a corridor of life from one part of the reef to another. The bottle reefs are joined together and are all planted with a range of coral biscuits grown in our coral nursery.  From bottles that we recycle into reef, it is possible to significantly increase the biodiversity of a previously barren areas.

The line of ribbon reef offers safe refuge for small fish moving across a rubble field.

Step Reefs

We’ve developed step reefs for steep slopes of rubble. We start with a bottle reef turned upside down so that the bottles create caves under the reef. These are good for slope stabilisation and can have a variety of corals planted on the top. We use these on Pom Pom island because the reef slope is quite steep and is very unstable. We normally fix many of these reefs together to create step reefs which are more stable and attract more marine life.

Corals grown as biscuits transplanted into sockets on the top of the step reefs.

Tracc Guide

Here’s a Tracc Guide about our bottle reef construction.