ARNHEM, Netherlands (AP) — Just like the animals on Noah’s Ark, the corals arrived in a pair.

On Monday, divers with gloved hands gently nestled the self-bred corals from the World Coral Conservatory project among their cousins in Europe’s largest coral reef at the Burgers’ Zoo in the Netherlands.

“This is the first project where we started to keep these corals with a known origin. As we know exactly where they’re coming from, they have the potential to be placed back into the wild. … So it is very important to keep these corals, as it’s going not very well in the wild,” Nienke Klerks, a biologist at the Royal Burgers’ Zoo in Arnhem, told The Associated Press.

It’s among several projects worldwide seeking to address the decline of coral reef populations, which are suffering from bleaching caused by rising sea temperatures. Corals are central to marine ecosystems, and while these projects won’t stem the tide of damage from human-caused climate change, they are seen as part of broader solutions.