Coral bleaching is a process that happens naturally and often regularly. Even on healthy reefs. It is the process in which coral polyps expel the “algae” living inside of their tissues. These algae live in symbiosis with the actual coral animals (polyps) and produce oxygen and nutrients in exchange for shelter and nutrients for themselves.
Under certain circumstances coral polyps get stressed. For example when water temperatures rise.
To “relax”, corals discard what they “think” causes their problems: their zooxanthellae. But doing that, corals not only lose an important partner in symbiosis and food source, but also all pigments that give the zoox (and with them, the coral) their colour. What remains is just the bare, white skeleton and the transparent coral polyps. This is what you will recognize as a bleached coral. Corals cannot recover from this discarding in all cases.
CoralGardening works on providing corals a healthy and stable environment to thrive in. And we can use your help.