Scientists at the National Oceanic and Atmospheric Administration noted that the latest El Nino event triggered the longest and most devastating coral bleaching event in mankind’s history.
Researchers said that it is the first time such event with tremendous impact on world’s reef enters a third year. For instance, if the phenomenon is observed off Florida’s and Hawaii’s coastlines, it would be the third time in a row coral bleaching affects the U.S. corals.
Coral bleaching occurs when sea temperatures are unusually high for teh season so corals are under a lot of stress. When a critical limit is reached, corals expel the symbiotic algae living inside them and thus lose their beautiful colors and turn completely white.
Corals can recover from bleaching, but their ability to recover gets weaker as consecutive events occur. Corals’ ability to survive such incidents is also influenced by the amount of thermal stress. For instance, in some regions of the world, sea temperatures rose only slightly, so corals there are not at a high risk of early death.
But the reefs with the highest chances of dying from this year’s incoming bleaching event are those around the Palau Archipelago and other islands in Micronesia. NOAA experts estimate that there are 90 percent chances for the corals there to be affected by bleaching by year’s end as La Nina is about to soon replace El Nino.
NOAA researchers, who described the reefs as “spectacular,” explained that the said islands need corals to stay healthy because they attract fish that the population needs to feed on and tourists who are also important for the economy
Still, federal experts don’t know whether coral bleaching will be as severe in Florida and Hawaii. But if this year the reefs in the two states are affected by another coral bleaching event, the chances of survival will be extremely low as this would be the third consecutive event since 2014.
Biologists explained that neither Florida nor Hawaii ever had to face a third consecutive event. So it is unclear what the consequences may be. Of the two U.S. states, Hawaii was the worst hit. In 2014, about 85 to 100 percent of the corals in northwest died because of bleaching. A year later, the island’s reef was hit once more by a bleaching event.
Florida, which hosts the second largest barrier reef on the planet (the first being the Great Barrier Reef in Australia), experienced two bleaching events in 2014 and 2015, but the latest was paired with a coral disease outbreak which has weakened the reef even further.
Image Source: Pixabay