The familiar blaze of color, it’s gone. Because of warmer sea temperatures, parts of the Great Barrier Reef have once again been hit by massive coral bleaching – the third in five years.
As aerial photographs show, some areas of the world’s largest reef that have been spared or are largely spared have been affected by moderate or even heavy bleaching. This was announced by the Great Barrier Reef Marine Park Authority (GBRMPA) on Thursday.
Fading of the colorful stone corals is called bleaching: if the water temperature is too high, the cnidarians repel the algae that cause the coloring. And without these so-called zooxanthellae, they cannot survive in the long run and die if the algae do not resettle within a short time.
The Great Barrier Reef extends over an area of more than 344,000 square kilometers, exceeding the size of Italy. As early as 2016 and 2017, an estimated one-third to half of the corals had died after sea temperatures rose. But not all bleached corals die: lightly or moderately bleached corals can recover. We can only hope that this also applies to this part of the reef.