The Great Barrier Reef Cannot Recover From Severe Coral Bleaching


A new study argues that global warming is more dangerous than it was previously thought. The Great Barrier Reef is losing the ability to regenerate and mitigate damage caused to the ecosystem by coral bleaching episodes.

More than half the Great Barrier Reef disappeared in 2016 and 2017. The warmer ocean water leads to mass bleaching. In the case of corals, bleaching occurs when the warm water forces the coral to expel the algae which live inside it. The study notes that the number of coral larvae on the reef fell by 89% in 2018, in comparison to previous historical levels. A smaller number of adults can withstand the bleaching while the increased mortality rates and dead coral prevent the establishment of new generations.

The sharp decline heralds a grim future for the reef. The mixture of coral species is already changing, and it is likely that the habitability will continue to decrease in the long run. A group of weedy corals as already overtook spawning acroporids, a specific type of coral which plays an essential role in allowing the reef to reach the structural complexity favored by a large number of animal species.

The southern Great Barrier Reef is in a better state than the northern side

One of the researchers has likened to the phenomenon to a forest where brambles replace the massive oaks. The decline of the regenerative capabilities can be seen in the northern and central areas of the Great Barrier Reef, where many corals died. The southern regions are in a better state since the bleaching didn’t influence them in a significant way.

It is unlikely that the southern Great Barrier Reef reef will be able to help the northern one since the distances between them are too large and the ocean currents aren’t going in the right direction.

At this point the researchers aren’t sure of the reef will be able to make a few recoveries, as the episodes of bleaching tend to appear more often. In just a few decades the rate grew from one every 25 years to one every six years.


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