May 11, 2022 - Energy & Environment

91% of reefs studied on Great Barrier Reef hit by coral bleaching

 This picture taken on March 7, 2022 shows a diver swimming amongst the coral on the Great Barrier Reef, off the coast of the Australian state of Queensland.
A diver swimming among the coral of the Great Barrier Reef, off the coast of the Australian state of Queensland, last March. Photo: Glenn Nicholls/AFP via Getty Images

Coral bleaching affected 91% of reefs surveyed along the Great Barrier Reef this year, according to a new report by Australian government scientists.

Why it matters: The report confirms a sixth mass bleaching event since 1998 occurred at the world's largest coral reef ecosystem in March due to a heat wave driven by climate change. It's the fourth such event since 2016, notes the report, which warns climate change "remains the greatest threat" to the ecosystem.

  • "Unusually, this was the first mass bleaching event to occur under La Niña conditions," writes the Great Barrier Reef Marine Park Authority in the report, published late Tuesday.

By the numbers: The Great Barrier Reef spans some 1,400 miles and is a haven for biodiversity, with thousands of species of plants and animals, including some 4,000 species of fish and 700 different types of coral.

  • The government scientists found that 654 of the 719 reefs they surveyed from a low flying aircraft over the Australian summer season of 2021-2022 "exhibited some bleaching," according to the report.

What they found: "The Great Barrier Reef’s waters warmed early in December 2021, exceeding historical summer maximums that typically occur in the hottest summer months," per the report.  

  • "Ocean temperatures continued to accumulate heat throughout the summer until early April 2022, with three distinct heat waves increasing thermal stress throughout the Central and Northern Great Barrier Reef," the report added.

The big picture: Prime Minister Scott Morrison's conservative Liberal-National coalition government has been criticized for failing to protect the World Heritage-listed Great Barrier Reef and not doing enough to tackle climate change with its focus on fossil fuel exports.

What to watch: Australia is holding a federal election on May 21, and the Morrison government last year pledged a net zero emissions target by 2050 and to reduce emissions by 26% on 2005 levels in 2030, per the BBC.

  • The opposition Labor Party's goal has vowed to cut emissions by 43% in 2030.

Read the full report, via DocumentCloud:

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