Thai scientists breed coral in labs to restore degraded reefs

Story and photos by Reuters

On a starry night, four Thai marine biologists swam through shallow waters off an island in the country’s southeast as billions of pink specks floated up from the ocean floor in a spectacle that takes place once a year.

The specks were sperm and eggs released by coral. The scientists collect as many samples as possible for breeding as they fight to save Thailand’s expansive reefs from degradation driven by warming oceans and human activity such as tourism.

Their research is painstaking: The coral only spawn once a year, and it can take five years to raise the juveniles in a lab before they are ready to return to the seabed. “We have hope that the degraded coral reefs can recover and return to their former beauty,” marine biologist Nantika Kitsom said in March 2024.

The loss of Thailand’s reefs doesn’t just pose a significant threat to the ocean ecosystem, but also to the country’s economy, as it harms tourism and fisheries that depend on healthy coral habitats for fish populations.

Thailand’s Marine and Coastal Resources Department started the coral breeding and restoration project in 2016 on Man Nai, which houses about 100 species of coral. Mass bleaching that started in 2010, most likely triggered by rising water temperatures, affected as much as 90% of Thailand’s coral reefs. Bleaching threatens wide swaths of tropical reefs globally, according to the United States National Oceanic and Atmospheric Administration.

Since the Thai project began, more than 4,000 coral colonies around Man Nai have been restored, officials said.