New ‘Seedbox’ Technology Could Help Restore the Great Barrier Reef

Scientists are testing an innovative new technology that could help restore damaged sections of the Great Barrier Reef in Australia by giving millions of young corals a better chance of settling and surviving.

Known as the larval seedbox, the simple device has been developed by researchers from CSIRO and Southern Cross University as a way of delivering coral larvae to areas of reef that need restoration.

The technology is being tested as part of wider efforts to develop new ways of restoring coral reefs at a much larger scale.

How Does the Coral Seedbox Work?

Corals reproduce during mass spawning events, when many species release eggs and sperm into the water. Once fertilised, the resulting coral larvae must survive predators, currents and other challenges before finding a suitable surface on which to settle.

The larval seedbox is designed to improve those chances.

The clear, rectangular container has fine mesh windows that allow seawater to flow through, along with openings at its base through which the coral larvae can leave.

Rather than releasing all the larvae at once, the seedbox allows them to disperse gradually over a period of around 12 to 24 hours.

This gives the larvae more time to find suitable areas of reef and is intended to increase the number that successfully settle.

Early Results Are Promising

The first pilot study took place at Lizard Island in November 2024.

Researchers found coral settlement rates of up to 56 times higher than natural levels, across thousands of square metres of reef. The trial involved the delayed release of around 14 million coral larvae across approximately two hectares.

The technology was tested again during the Great Barrier Reef’s coral spawning season in November 2025, this time in the Whitsundays.

Researchers deployed 19 seedboxes at Hook Island, with each box containing an estimated 550,000 coral larvae.

Preliminary results showed high levels of coral settlement around the seedboxes, with some areas recording more than 100 times the usual level of coral settlement.

The research team plans to return to the Reef to assess how well the corals have developed over a nine-month period.

Scaling Up Coral Reef Restoration

The researchers say the seedbox could complement existing coral restoration techniques, including Coral IVF, by providing a way to deliver large numbers of coral larvae over wider areas.

The approach is particularly relevant to reefs that have been affected by extreme weather events, coral bleaching and other pressures.

The technology was developed through the Reef Restoration and Adaptation Program and is being trialled by CSIRO and Southern Cross University in partnership with the Australian Institute of Marine Science and local stakeholders.

If further trials show that the seedboxes can consistently improve coral settlement under different conditions, they could become another tool for restoring damaged reefs at a much larger scale.

For a technology that consists of little more than a box, mesh and a carefully timed release system, the potential could be considerable.

Source: CSIRO