The massive episode of coral bleaching around the world, caused by record ocean temperatures, continues to expand and worsen, a US government agency warned on Thursday.
The National Oceanic and Atmospheric Administration (NOAA) announced in mid-April that the world was experiencing a new massive episode of coral bleaching. This is the fourth recorded since 1998.
The phenomenon, which threatens the survival of coral reefs, has already been confirmed in 62 countries and territories, in both the northern and southern hemispheres.
“I am very concerned about the state of the world’s coral reefs,” Derek Manzello, coordinator of NOAA’s coral program, said at a press conference.
Since the announcement of this new episode a month ago, “nine other countries and territories have reported severe coral bleaching, including India and Sri Lanka,” he said. “This illustrates that this event is growing in size and impact.”
No less than 60.5% of the world’s coral reef surface area was affected by thermal stress during the last 12 months, a one-year record, according to NOAA.
But the previous global mass bleaching event, which took place between 2014 and 2017, remains the worst in terms of cumulative impact and duration — at least for now, he said.
The current episode is expected to persist and spread to new areas during the summer. The Caribbean in particular is already starting to see the heat build up, extremely early in the year.
Already, the Great Barrier Reef, in the northeast of Australia, is affected. Access to Thailand’s Pling Island and Phuket Island Coastal National Park was closed last week in an attempt to protect corals.
This event “would not happen without climate change,” insisted Derek Manzello.
The oceans have been recording record temperatures for months: last month was the warmest in the seas for an April, representing the 13th consecutive month of monthly record.
The accumulation of heat “was particularly extreme and unprecedented in the Atlantic Ocean,” said Derek Manzello.
Understanding the extent of the consequences of this bleaching episode for corals will take time, he added. In the Caribbean, for example, corals surviving the heat could die within a year or two “from diseases or concentrations of predators”, he explained.
The year 2023 was the hottest year on record, driven by climate change accentuated by the cyclical El Nino phenomenon.
The opposite phenomenon, La Nina, is expected by summer or fall, according to NOAA meteorologist Dan Collins.
“My hope is that when La Nina really sets in, the percentage of reefs affected will start to decrease,” Derek Manzello said.
According to NOAA, the year 2024 still has a 61% chance of surpassing last year by becoming the hottest on record.
