In the ongoing endeavor to map our sea floors and understand climate change, another amazing discovery has been made. The Caitlin Seaview Survey team out of Queensland University in Australia is headed by Dr. Pm Bongaert and says their recent discovery is “mind blowing.” Found on the outer portion of the Great Barrier Reef called Ribbon Reefs, Leptoseris sp. was discovered at depths far greater than was thought possible for a light dependent coral. Photo courtesy of Geoff Schultz The team was able to deploy their remote-operated vehicle in calm seas and found the coral at a depth of 410 feet (125 meters.) At that depth there is little to no light for corals that harbor light dependent symbiotic algae called Zooxanthellea. These discoveries “show just how little we really know about the reef and how much more is yet to be discovered” said Dr. Bongaert. Read more here!

Australian National University researchers have discovered ocean reefs are stronger than we once thought. Coralline algae acts as a bonding agent on reefs holding colonies together and creating shelves that protect more fragile species from the violent crashing of waves. The mineral structure of coralline was studied and published in Nature Climate Change and coauthored by a researcher at Scripps Institution of Oceanography at UC San Diego. “A coral reef is like a house-the coral are the bricks, but the coralline algae are the cement that holds it all together,” explains Merinda Nash, lead author and Ph.D. candidate with the ANU Research School of Physics & Engineering.  Their discovery included an extra mineral in the structure of coralline, dolomite. This mineral makes the coralline less dissolvable in oceans waters that are rising in acidity.  “This newly found mechanism of ocean acidification resistance means corals of the future with healthy coralline algae can fight damage from high wave energy, tsunamis and other threats” said Davey Kline, a Scripps marine biologist and coauthor of the new paper. The basic components of a hard coral skeleton were previously thought to be simply calcium carbonate and magnesium calcite, but these findings “will help the management and preservation of coral reefs, with the data applied to protect the most vulnerable parts of the reefs.” said Kline. Read more here!

A new study conducted by the Southampton University sheds some light on the subject of how corals can use their chromoproteins (pigments) to protect themselves from high levels of light. In areas of the natural reef where low tides and shallow waters expose corals to extreme levels of light corals have adapted a method of screening themselves from the harmful light produced by our sun. In this study scientists have theorized that the chromoprotein colors pink and purple can reduce the amount of light absorbed by the coral by breaking down the spectrum; the light dependent symbiotic algae (zooxanthellae) living within the coral is thus protected by the chromoproteins.  Dr Jorg Wiedenmann posits: “GFP-like proteins were suggested to contribute to the protection of corals and their symbionts from excess sunlight. This hypothesis has been controversially discussed as the mechanism as to how these pigments function remained unclear. At least for the chromoproteins we know now that they have indeed the capacity to fulfill this function.” Dr Wiedenmann’s findings are extremely interesting when discussing the phenomenon of how corals seem to accumulate higher levels of chromoproteins in areas of growth: “These growing areas contain essentially no symbiotic algae, so much of the light is reflected by the white coral skeleton instead of being used by the algae. The resulting increased light intensities in the new parts of the coral represent a potential danger for the algal cells that need to colonize these areas. Hence, it seems that the corals use a clever trick to help their symbionts. The higher light intensity switches on the genes that are responsible for the production of the sunscreening chromoproteins. This study adds to the knowledge of stress resilience in coral and is a contribution to the fight against anthropogenic instabilities. Read more here!