Coral Gardeners, a social impact organization in French Polynesia, is bringing artificial intelligence below the waves to assess coral restoration based on the reef’s shape and sound.

Founded five years ago by Mo’orea local Titouan Bernicot, Coral Gardeners has three nurseries across French Polynesia that house nearly 9,000 coral outplants. It has partnered with two academic institutions to pilot new aquatic bioacoustics and photogrammetry programs that will better assess the organization’s restoration efforts.

Sound is abundant in the ocean far beyond the marquee calls of large animals like dolphins and whales. “Many fish species, perhaps even a majority, also use sounds to communicate,” says Dr. Aaron N. Rice, a principal ecologist at Cornell University who studies bioacoustics, the scientific field of understanding how and why animals communicate using sound. “By listening to restored reefs, we can start to get a sense of whether restored coral reefs are starting to sound like healthy and stable reef systems, or whether additional restoration activities and interventions are needed.”

Coral Gardeners and the Cornell team created a bioacoustic AI model of the reef soundscape recorded by ReefOS, a network of sensors and cameras collecting continuous data at the Maharepa and Cook's Bay nurseries.

“…[T]he sounds that reef-associated organisms produce can tell us a lot about both the health of the reef, and whether restoration efforts are sufficient or need to continue to revitalize reefs,” Rice says. “We’re hoping that sounds can tell us when a coral reef can officially be considered ‘restored’ so the Coral Gardeners team can move on to the next restoration site.”

The group Coral Gardeners also teamed up with the University of Hawai’i to integrate advanced 3D mapping and photogrammetry, the science of extracting information from photographs, into the monitoring process. By modeling the structure of the reef, the team can assess critical metrics such as biomass and coral growth rate to improve restoration methods.

Reef restoration programs have increased in popularity in recent years around the world to counteract unprecedented coral loss. Globally, upwards of 50 percent of coral cover has been lost in the past 30 years, according to the UN Environment Program. The world could lose as much as 90 percent of its coral by 2050 even if global warming is limited to an increase of 1.5°C, according to the most recent Intergovernmental Panel on Climate Change Assessment Report. Additional UN research suggests severe coral bleaching may become an annual event by 2034.

Coral Gardeners' Bernicot hopes programs like his will pave the way for others to help address the challenge.

"I don't want ocean conservation to be a part-time job," he says. "I want people that love the ocean to be able to make a career saving their playgrounds.”