Marine ecologists have found the most gigantic corals of the Great Barrier Reef off the coast of the Palm Islands. Its width is 10.4 meters. The discovery is reported by Scientific Reports.
The coral was named Muga dhambi, which is translated from the language of the local people of Manbarra as “big coral”. According to ecologists, the find is more than 400 years old.
“The large corals Porites on Gulbudi Island (Orpheus) are unusually rare and resilient,” wrote James Cook University marine ecologist Adam Smith and colleagues. “It has survived coral bleaching, invasive interventions, cyclones, high tides and human activities for over 400 years.”
The coral’s flanks are still home to its creators – algal symbiotes and zooxanthellates. But part of its top is already empty. Instead, green sponges (Cliona viridis), algae and other types of corals (Acropora and Montipora species) have settled here, it is their competition for the remaining space that forms new clear lines on the coral skeleton.
Discovered sponges are often found on the rugged side of corals, where they are exposed to stronger currents and make it easier for bacteria and other microbes to filter the water. True, it is the sponges that contribute to the destruction of the coral. In addition, some of the coral tissue can die from exposure to the sun during low tides or warm water.
Scientists have also found high-density “stress bands” recorded in the structure of the coral, dating from about 1877. Such bands appear much more often due to anthropogenic global warming. But this coral community is very resilient: it has experienced nearly 100 bleaching events and up to 80 large cyclones during its existence, as well as degraded water quality.