Natalie Levy, a post-doctoral researcher, counts settled coral larvae with an ultraviolet light on the synthetically coated microhabitat structures. Credit: O. Boulais

Coral reefs are vital to marine biodiversity, but their livelihood is under threat due to climate instability and the impacts of human activities.

Rehabilitating marine environments requires innovative solutions. Oc茅ane Boulais, a doctoral student at the Scripps Institution of Oceanography, studies one of these potential solutions: the impacts of acoustics on coral larval recruitment and settlement.

After spawning, coral larvae drift or swim through the , seeking suitable sites to find a home to attach to along the ocean floor.

"Multiple have already been identified as that stimulate this settling behavior, presumably by indicating to the larvae when other successful-settled coral structures are nearby," said Boulais. "A growing body of evidence over the past 20 years is also finding that sound may be another such cue."

Healthy reefs are acoustically rich environments, filled with fish croaks and shrimp snaps. Boulais and their collaborators mimicked these sound environments to study the effects of sounds on 19 artificial coral settlement modules placed in K膩ne驶ohe Bay, Oahu, Hawaii.

The researchers recorded audio near a vibrant reef, which they replayed at various distances from their artificial microhabitats. The artificial microhabitats were coated with a bacteria designed to induce larval settlement, creating a suitable habitat for attracting coral larvae.

Boulais will present details on their findings about the impacts sound has on Thursday, May 22, at 9:20 a.m. CT as part of the joint , running May 18鈥23. Notably, there were significant increases in coral settlement close to the speakers.

The researchers are planning an additional data deployment in the summer of 2025. Boulais said they hope to ultimately develop scalable strategies to study larger reef structures with audiovisual remote sensing tools, using low-cost cameras for continuously monitoring the reef's biodiversity.

"Innovative, interdisciplinary approaches鈥攃ombining science, technology, and creativity鈥攃an offer powerful solutions to pressing environmental challenges like coral reef degradation," Boulais said. "Ultimately, I hope this research inspires both urgency and hope for the future of ."