This year is on track to be the worst on record for coral because of rising ocean temperatures, the New York Times reported.
What's happening?
The temperature of the ocean has risen dramatically this year, setting records.
In response, coral reefs worldwide are undergoing "bleaching" — an event in which the coral loses its algae symbiotes and turns white because of the water being too hot, the Times explained. Coral can recover from bleaching if the temperature drops soon afterwards, but if it stays hot, the coral dies.
A "global bleaching event" occurs when at least 12% of the corals in the three main ocean basins that contain them — the Pacific, Indian, and Atlantic — experience bleaching within the same 365-day period. According to the Times, there are four major global bleaching events on record, in 1998, 2010, 2014-2017, and today. The first affected 20% of all corals; the second, 35%; and the third bleached 56%.
As of April 15, this most recent bleaching event had affected 54% of the world's corals and climbing, the Times revealed.
Derek Manzello, coordinator of NOAA's Coral Reef Watch program, told the Times that the portion of the world's coral being affected was increasing by about 1% per week, and that within a week or two, "this event is likely to be the most spatially extensive global bleaching event on record."
Ove Hoegh-Guldberg, a professor of marine studies at the University of Queensland, said: "I do get depressed sometimes, because the feeling is like, 'My God, this is happening.'"
Why does coral bleaching matter?
Coral is a slow-growing organism, so damage to coral reefs can take decades to heal if they recover at all.
"This is scary, because coral reefs are so important," said Manzello.
Indeed, the Times estimated the economic value of the world's reefs at $2.7 trillion per year. They protect coastlines from erosion, and they shelter about a quarter of the world's marine species during some point in their life cycles, including many species that people rely on for food.
What's being done about this issue?
Scientists have spent decades looking for faster and more effective ways to grow coral. Recent results have been promising, growing manmade reefs in as little as four years.
At the same time, people around the world are trying to stop the Earth from overheating by reducing the heat-trapping gases they put into the atmosphere. They're switching from gas cars and appliances to electric and supporting companies that share their goals.
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