Great Barrier Reef suffers third mass bleaching in 5 years

March 26, 2020

Australia’s Great Barrier Reef Marine Park Authority (GBRMPA) on Thursday confirmed “widespread coral bleaching” is occurring on the reef.

Aerial surveys showed that “some southern areas of the Reef that had little or no bleaching in 2016 and 2017 have now experienced moderate or severe bleaching,” the authority said.

Warmer temperatures, particularly in February, led to the latest bleaching, the GBRMPA said. Bleaching does not automatically mean the corals will die. Mildly or moderately affected reefs usually recover.

Key tourism reefs in northern and central areas should survive, the authorities said.

Ocean warming in 2016 and 2017 killed almost half the coral.

The Great Barrier Reef is the world’s largest coral system. Climate change remains the greatest threat to the reef, according to the GBRMPA.

Time running out to save the world’s coral reefs

Trouble in paradise

Some 2,500 scientists, policymakers and managers came together in Honolulu in June 2016 for the world’s largest summit dedicated to the future of coral reefs. With coral reefs threatened by global warming, participants at the 13th International Coral Reef Symposium are calling for a joint rescue effort.

Time running out to save the world’s coral reefs

World is watching

The event gathered guests from 97 countries, including the presidents of Palau, Micronesia, and the Marshall Islands. Coral reefs are a key source of income in those countries, mostly through tourism.

Time running out to save the world’s coral reefs

Too warm for comfort

The Pacific nations are worried about the future of their tourist hotspots, as coral reefs face so-called “bleaching” due to rising sea temperatures. “If our coral reefs are further degraded, then our reef-dependent communities will suffer and be displaced,” leaders of Palau, Micronesia, and the Marshall Islands said in an open letter.

Time running out to save the world’s coral reefs

Corals in crisis

Bleaching happens when coral is stressed by hot ocean waters or other changes in the environment. In response, corals may release tiny symbiotic algae which drains them of color. More importantly, bleaching affects their ability to feed and reproduce.

Time running out to save the world’s coral reefs

Pale as death

Severe or prolonged bleaching might kill off corals entirely. Scientists have detected bleached coral in the past two years in oceans around the world. They expect the process to continue thought 2016.

Time running out to save the world’s coral reefs

Giant from Down Under

The 2,300-kilometer-long (1,429-mile-long) Great Barrier Reef is the world’s largest coral reef system and its largest living structure. It is also among Australia’s main tourist attractions, generating around $3.9 billion (3.5 billion euros) annually.

Time running out to save the world’s coral reefs

Tough times for the Great Barrier Reef

Almost one-half of the coral in the reef’s northern third have died in the past three months [in 2016], according to James Cook University professor Terry Hughes. The most affected area is remote and unpolluted, with very little fishing and no coastal development. “That’s an absolute catastrophe,” Hughes said. “There’s nowhere to hide from climate change.”

Time running out to save the world’s coral reefs

Fighting for hope

Despite the bad news, scientists claim the problems can be managed with proper funding and political backing. “We are not ready to write the obituary for coral reefs,” Professor Hughes said. The scientific community at the conference pledged to work with leaders across the world in order to “curb the continued loss of coral reefs.”

Author: Darko Janjevic (with AP)