Can Reefs Survive Coral Bleaching?

Scientists in Australia recently announced that more than 90% of coral reefs in the Great Barrier Reef have experienced bleaching this year due to increased oceanic temperatures from climate change. This is the third mass bleaching event on record and possibly the worst yet — affecting one-third of the world’s corals. Other affected areas include Micronesia, as well as the Caribbean and Hawaii, both of which suffered major bleaching throughout their waters last summer.

Coral reefs provide food and shelter for numerous marine species and they support fish stocks that feed more than one billion people around the world. According to The New York Times, they provide jobs for “an estimated 30 million small-scale fishermen and women [who] depend on reefs for their livelihoods.”

Coral reefs in the Gardens of the Queen (Noel Lopez Fernandez)

A healthy coral reef comprises millions of tiny coral polyps and algae (calledzooxanthellae) living together in a symbiotic relationship. Colorful algae, lending coral reefs their vibrant colors, make sugars that provide corals with 90% of their nutrition. Bleaching occurs when environmental stressors, such as prolonged exposure to warmer waters, cause the corals to expel the algae.

If those environmental stressors are brief and infrequent, corals and algae will resume their symbiotic relationship and the corals will recover. However, without the algae, the corals are left to die, along with many marine other species they support.

Scientists fear that the affected corals may never recover if the waters do not cool off soon. But there may be hope: According to the World Resources Institute, “reducing local pressures on reefs —overfishing, coastal development, and pollution — is the best way to ‘buy time’ for reefs” and increase their resilience to warmer waters. 

For example, coral reefs in the Gardens of the Queen in Cuba exhibit increased resilience to warmer ocean temperatures than their surrounding Caribbean neighbors. This may be because of the Gardens’ relative isolation and thus lower pollution and fishing levels than neighboring areas. 

Conservationists in Australia have urged the government to take immediate action against climate change, illegal fishing and pollution to help the Great Barrier Reef to better resist and survive bleaching events. 

WildAid helps to protect reefs around the world by encouraging the community to reduce their carbon footprint toaddress climate change. Our marine program prevents unsustainable fishing practices through our comprehensive marine protection model to increase coral reef resilience in the Northern Reefs in Palau, West Papua, Indonesia and Ecuador.

Coral bleaching infographic (NOAA)

Article and images sourced from http://wildaid.org/news/increasing-coral-reef-resilience-combat-coral-bleaching