The health of coral reefs is a topic that remains under intense study here in Hawaiʻi and in other parts of the world. That includes the largest coral reef system in the world where scientists are reporting some troubling developments.
Australia’s Great Barrier Reef is going through a mass coral bleaching event — again.
Scientists say this is the sixth time the reef has been hit with mass bleaching — but it’s the first time it’s happened in the year of a La Niña weather system — when ocean temperatures are usually cooler around Australia.
Bleaching is discoloration that’s caused when algae leave the coral tissue — often as a result of warming ocean temperatures.
The U.S. National Oceanic and Atmospheric Administration says that without algae, the coral loses its main source of food — making it more susceptible to disease — and turning its color to pale or a ghostly white.
Australia’s lead management agency for the Great Barrier Reef recently completed aerial surveys across a sample of 750 reefs.
It found severe bleaching among 60% of the corals.
Scientists involved in the latest study do add a note of hope — writing that the “bleached coral is stressed, but still alive.”
The report says, “If conditions moderate, bleached corals can recover from this stress, as was the case in 2020, when there was very low coral mortality associated with a mass bleaching event.”
