Climate crisis: coral bleaching, a worrying symptom of record ocean temperatures
Cairo: Hani Kamal El-Din
The world’s coral reefs are dying. In publication dated Monday April 15, the American Oceanic and Atmospheric Observation Agency (NOAA) warns of a massive episode of coral bleaching worldwide due to record ocean temperatures. This phenomenon of coral dieback threatens the very survival of reefs.
“As the world’s oceans continue to warm, coral bleaching is becoming more frequent and severe. When these events are severe or prolonged enough, they can cause coral mortality.”the researcher was alarmed Derek Manzello, who coordinates NOAA’s Coral Reef Observatory. This global bleaching of corals on a planetary scale is the fourth recorded by thegency since 1985, the third in fifteen years after 2010 and 2016.
While the ocean surface temperature reached a record level in February (21.06°C), under the effect of global warming caused by human activities, the bleaching phenomenon is due to the rise in ocean temperatures. water in the seas and oceans. Due to thermal stress caused by heat, coral colonies, which are made up of tiny creatures called polyps, eject them symbiotic algae that they shelter and which provide them with nutrients. “Without these algae, which have various colors, these corals become transparent and we can see their limestone skeleton, which gives them this white tint”explains Jean-Pierre Gattuso, research director at the oceanography laboratory in Villefranche-sur-Mer (Alpes-Maritimes).
The phenomenon is not irreversible: Affected corals can survive if temperatures drop and other stressors (overfishing, pollution, human activities) are reduced. But the trend is not good.
