Coral Bleaching occurs due to increases in oceanic temperature levels. Coral organisms maintain a symbiotic relationship with microscopic algae known as zooxanthellae which also contribute to their vibrant colours. Rising temperatures can lead this algae to photosynthesize too quickly forcing the coral to expel them in order to protect its own tissue.
If temperatures remain high for prolonged periods of time (NAOO, 2016), corals are unable to recover. In 2014 alone, a team of researches conducting expeditions in Australia’s Great Barrier Reef identified a 40% reduction in coral calcification rates when compared with those recorded in the 1970.