Korallfehéredés

Korallfehéredés, also known as coral bleaching, is a phenomenon where corals lose their symbiotic algae, called zooxanthellae, which live in their tissues and provide them with color and nutrients. This loss is primarily triggered by environmental stressors, most notably rising ocean temperatures. When water temperatures become too warm for too long, the zooxanthellae become toxic to the coral, and the coral expels them.

Without the zooxanthellae, the coral's white calcium carbonate skeleton becomes visible, giving it a bleached appearance. While bleached corals are not dead, they are under severe stress and are more susceptible to disease. If the stressful conditions persist, the coral will eventually die. If the conditions improve and the water temperature returns to normal, corals can regain their zooxanthellae and recover.

Other factors that can contribute to coral bleaching include pollution, changes in salinity, and increased solar radiation. Mass bleaching events, affecting large areas of coral reefs, have become more frequent and severe in recent decades, largely attributed to climate change. The widespread loss of coral reefs due to bleaching has significant ecological and economic consequences, impacting marine biodiversity, fisheries, and coastal protection.