Coral bleaching is affecting more than 90 percent of the Great Barrier Reef off Australia’s northeast coast due to high sea temperatures. A month-long heat wave on the Fifth Continent was the trigger, according to a new report by the Marine Parks Authority (GBRMPA), which reports to the government in Canberra. Aerial photographs had shown that of 719 reefs surveyed, 654 exhibited at least partial coral bleaching.
The extremely hot weather has continued to heat up the seawater since December. The result: the corals, which belong to the cnidarian family, are so stressed that they shed the algae that are responsible for the colouration, with which they otherwise live. they fade.
“The investigations confirm a mass bleaching,” says the report. Numerous reefs are affected in all regions of the 2,300-kilometer-long natural wonder that stretches from Cape York to Bundaberg in tropical Queensland. It is already the fourth mass bleaching since 2016 and the sixth since 1998, writes the authority. However, she added, “It’s important to note that bleached corals are stressed but still alive.” If the water cools, bleached corals may regain their color and survive. According to the Federal Environment Ministry, this takes 10 to 15 years at best. In view of the progressing climate change, it seems questionable whether the extremely species-rich and valuable ecosystem will be granted this time.
In 2021, Unesco threatened to put the reef on the Red List of World Heritage in Danger. However, under pressure from the government, it just barely escaped the downgrade. It will not be discussed again until 2023. Prime Minister Scott Morrison unveiled a package of measures to protect the reef in January. A total of one billion Australian dollars (630 million euros) is to be invested in measures to preserve the ecosystem over a period of nine years. dpa/AnL