HAB response: using sound to support reef recovery on Kangaroo Island

As part of our ongoing contribution to South Australia’s HAB response, we’ve deployed a new AusOcean Rig with underwater speakers on the shellfish reef off Kingscote on Kangaroo Island. This Rig is one of several tools we use to help marine environments recover after large-scale events, and Kingscote is an important place to start given the ecological role this reef system plays in Backstairs Passage.

Towing the Rig out to site

The underwater speakers broadcast recordings of healthy reef soundscapes — the natural cracks, pops and ambient noise produced by a thriving reef community. These sounds act as cues that guide baby oysters (spat) towards suitable habitat. During oyster recruitment season, when spat numbers are highest in the water column, these cues can make a significant difference to where young oysters choose to settle.

Oyster reefs are quiet achievers. They filter the water, provide structure for countless marine species, and stabilise the ecosystem around them. When a HAB event hits, these systems can take a knock, and recovery can be slow without a helping hand. By encouraging spat settlement now, we’re supporting the reef at a moment when it’s most ready to rebuild, essentially giving nature a bit of a nudge in the right direction.

One of the strengths of this approach is that it’s scalable. The Rig is low-cost, low-impact and can be deployed quickly, which is important when conditions change fast and the window for ecological recovery is tight. It also demonstrates how technology, when used thoughtfully, can work alongside natural processes rather than replace them. Our goal is always to amplify what ecosystems are already trying to do.

Finishing touches on the Rig

We know there’s no single solution to the challenges presented by HABs or the broader pressures on South Australia’s coastal waters. But tools like this help us chip away at the problem in practical, measurable ways.

This deployment is an important step, but it’s not the end point. We’d like to see more Rigs operating across the state to support habitat recovery in other affected areas. The more places we can assist natural processes to kick back into gear, the stronger and more resilient our marine environments will be in the long term.

Rig floating off Kingscote

AusOcean is a not-for-profit ocean research organisation that supports open source practices. Open source approaches to tackling environmental issues means embracing collaborative tools and workflows which enables processes and progress to be fully transparent. A critical aspect of working open is sharing data not only with your immediate team but with others across the world who can learn, adapt and contribute to collective research. By contributing to, and supporting open practices within the scientific community, we can accelerate research and encourage transparency. More info at https://www.ausocean.org/info.