Marine biologist Lorenzo Mittiga took photos of divers who were preserving and restoring the reefs on Bonaire in the Caribbean. /VCG Photo

Divers tend to "coral nurseries" where different species are grown before being planted into the wild in order to restore dying reefs. /VCG Photo

Over 900 tree-like structures were built underwater on the coast of Bonaire Island in the Caribbean, cultivating different strains of coral. /VCG Photo

Each 5ft (1.5 meters) PVC and fiberglass tree has 10 branches, which can hold around 100 of the young organisms. /VCG Photo