Aliyah Siddiqui
International Assistant Editor
A significant portion of the Great Barrier Reef in Australia suffered through its sixth mass bleaching effect, creating concern that the reef may not recover. Coral bleaching occurs when temperatures rise and the algae living inside reefs leave, causing corals to lose their food source and subsequently turn white. However, if temperatures cool for a long enough time, corals are able to recover.
According to The New York Times, Australian scientists used aerial photographs to examine the reef and found extreme bleaching in 60% of the corals. Bleaching was more severe in the corals closer to the shore and less severe in some northern parts of the reef. Scientists believe that the bleaching is an effect of the increase in ocean temperature despite this year’s La Niña, a time when increased rainfall and cooler temperatures usually reduce stress for corals.
“This is a first mass bleaching event during a La Niña,” said Emily Darling, a coral reef scientist at the Wildlife Conservation Society. “It continues to reinforce that with extreme heat waves and water getting too hot, corals are losing their recovery windows – those times between bleaching events when we know corals can recover.”
This recovery, however, has become rare in recent years. In a study published in 2021, scientists discovered that 14% of coral reefs were lost in the world. Given that a quarter of marine species and millions of people rely on coral reefs for food, protection or employment, scientists are continuing to advocate for the decrease in fossil fuel and carbon emissions to save the corals.
In Australia, however, the government has done little to reduce fossil fuel emissions and has urged the United Nations to keep the Great Barrier Reef from being named as an endangered world heritage site. According to The New York Times, the Australian government has instead poured money into reducing agricultural runoff, killing invasive species, and growing heat-resistant coral, sparking climate protests among Austrailians who view the government’s efforts as insufficient.
The Great Barrier Reef Foundation, a non-profit that helps preserve the Great Barrier Reef, is also promoting coral reefs in various ways.
“Reef management also has a vital role to play in helping to reduce additional stressors, such as crown-of-thorns starfish and poor water quality, and promoting rates of coral recovery,” said Mumby. “A number of programs under the Commonwealth-funded Reef Trust Partnership are devoted to this task, including improved control of crown-of-thorns starfish, partnering with farmers in mitigating pollution, exploring the potential for active reef restoration, and designing more targeted means of protecting the reef to increase effectiveness.”
Currently, scientists from the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the International Union for Conservation of Nature are in Australia as part of a monitoring mission for the Great Barrier Reef and will be briefed on the aerial findings and status of the reef.
According to The Washington Post, this is the fourth mass bleaching event since 2016, raising questions about the long-term damage the reef may face due to the back-to-back bleaching.
“It is too early to know the level of long-term damage that the bleaching has caused because many corals will recover once thermal stress declines,” said Peter Mumby, Australia’s Great Barrier Reef Foundation Chief Scientist. “However, based on what’s happened in the last five years, we would expect to see severe coral mortality in the shallowest regions of the worst affected reefs.”
