Loudspeakers to help restore dead coral reefs

Great Barrier Reef by Sarah Lou

An international research team has launched a new sound-based technique to help restore damaged coral to a healthy state.

The main idea of the technique is to place loudspeakers on damaged, dead, or dying coral and simulate the sound of healthy coral.

By emulating the sound of a thriving reef, this new technology aims to entice fish into making a home in otherwise empty areas.

Alexander Tudhope, a Professor of Climate studies at the University of Edinburgh, has worked on coral reefs for over 35 years.

He said: “The sound on healthy reefs is tangible. It’s totally different on dead ones.”

Orpheus Island, Great Barrier Reef by ARC CoE for Coral Reef Studies/ Greg Torda

He added that almost no fish settle in the silent graveyards, where coral used to live.

Without fish to clean and inhabit new coral, it would die rapidly, so an active population of fish is needed for conservation and restoration efforts to have any effect.

In the study carried out by the research team, twice as many fish arrived and settled in areas where the loudspeakers were installed and emitting healthy reef noises compared to dummy speakers and areas without any speakers.

However, Professor Tudhope is sceptical about how helpful the arrival of more fish will be in promoting recovery for the reef.

He said: “While this technology is really interesting, it doesn’t help against overfishing or climate change, which are two of the major factors that cause coral to die in the first place.”

In order for the technology to have any great impact, it must be combined with other tools that help to regenerate the coral itself.

Professor Tudhope added: “It won’t work on its own. First, we will need to fix the issues of there being too few nutrients for the new coral, and again, overfishing.”

He also emphasised the importance of combating climate change for coral conservation, saying “climate change is really what drives these issues”.

Coral is a delicate organism that responds quickly to changes in its environment, including temperature. As the effects of climate change continue to gradually warm the oceans, coral living in the most affected areas struggles to survive.

As Professor Tudhope explained, the other problems leading to coral death need to be addressed if reefs like the Great Barrier Reef are to be preserved.

More resources will have to be put towards efforts such as the current attempt by Hawaiian researchers to breed coral with greater temperature resistance. This so-called “super coral” will then have to be planted in damaged areas.

However, provided that the “super coral” approach becomes more widely available, and the global issues of climate change and overfishing are addressed, the loudspeaker technology could prove incredibly valuable.

Rather than restoring the original dead or damaged coral, this approach secures a future for new coral. This will make it very useful in the long run.

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