Evidence shows the rise in ocean temperatures due to global warming endangers coral species native to Brazil's coastal regions. Twenty out of 40 species of corals found in Brazil have not been observed anywhere else on the planet.

At the headquarters of the Living Coral Conservation Project, based in Arraial da Ajuda, Bahia, the phenomenon known as bleaching was observed even in corals raised in research tanks. The occurrence was first detected in March, after two months of warmer than usual water temperatures. The incident was the biggest ever seen in Brazil, and coral whitening could be observed in an area spanning 2.500 km, from Rio Grande do Norte to Ilha Grande, in Rio de Janeiro.

Bleaching occurs because some species of coral depend on micro-seaweed to survive. Seaweed acts as the coral's second layer. Like all plants, they rely on photosynthesis to transform sunlight into energy. Any leftover energy is then transferred to the coral in exchange for shelter.

When water temperature rises above normal levels, however, algae begin producing hydrogen peroxide, a substance toxic to coral. In order to protect itself, the coral repels the algae, exposing its own white skeleton underneath.

“Depending on the intensity and duration of the phenomenon, the coral might die, as we have observed in the Indian and Caribbean oceans”, says biologist Clóvis Barreira e Castro. “In these regions, certain coral reefs were practically decimated after this phenomenon was observed”.

