On any given day it is easy to come across news of how the ocean is in danger, coral reefs are dying, and the sky is generally falling in regards to the outlook for corals on this planet. That is why it is with great pleasure that we came across one account of an uplifting story from French Polynesia documenting an incredible rebound of corals and live growth following an epic die off of corals.
Coral and reef aquarium keepers are well familiar with the resilience of corals, and how seemingly dead corals and colonies can often “spring back” to life in a phenomenon dubbed the Phoenix Effect, which we have written about specifically. The Phoenix Effect and the concept of partial mortality is practically common knowledge among reef keepers, especially in regards to certain types of Fungiids, but the idea is beginning to receive more attention by the scientific community in regards to wild corals.
One of the first mass coral bleaching event to garner mainstream media attention was the 1997/1998 El-Nino bleaching which resulted in substantial losses of live coral cover across the Pacific Ocean. An area that was particularly hard hit by this bleaching event was French Polynesia, who’s reefs were thoroughly surveyed in the aftermath to determine the impact to coral cover.
Hundred and thousand year old colonies of massive and important reef-building Porites that live in shallow water were practically decimated. 15 years later researchers returning to survey the recovery of corals on those reefs were startled to observe an incredible rebound of live corals in the area.
It turns out that corals which were previously considered dead probably had slivers of living tissue, on the surface and inside the skeleton. From these remnants the corals were able to rise again like a Phoenix, using the existing skeleton as a framework on which the living coral tissue could grow. The result of the Phoenix Effect exhibited by these Porites resulted in an increase of live coral cover from 35% in 1998 to 74% in 2013 – very encouraging numbers indeed.
This is the embodiment of the Phoenix Effect which means corals have a much better fighting chance at surviving changing climate and other stressors that mankind is throwing at them. It’s important to note that the real reason for this incredible rebound by the corals is the ideal environment that allowed the coral to grow back without having to fight off other stressors. Current models used to predict how corals and coral reefs will change in the future do not have the Phoenix Effect factored in, meaning we can hope for corals reefs to be around a little bit longer than predicted, provided the environment is not further degraded. [MarBiol via BBC]