
Are humans to blame? Photo: Duke University

The things that are currently happening to the Great Barrier Reef are absolutely criminal. Climate change induced by a myriad of different human activities – and exacerbated by a particularly strong El Niño weather pattern this year – is bleaching the world’s largest coral system. And when coral is bleached, the stressed organisms shed a crucial photosynthetic algae, losing their beautiful color in the process. The effects of bleaching are harmful and damaging enough, but a new study by the Frontiers in Microbiology claims there is more bad news: The Great Barrier Reef appears to be severely infected with a herpes-like virus.
According to the IFL Science, a team of researchers found the grizzly discovery when they sampled various types of coral both in the laboratory and in the wild. After putting the coral through various types of stresses associated with bleaching, including high temperatures, intense UV light exposure, and simulations of heavy rainfall, the corals were found to contain high concentrations of virus-like particles (VLPs), non-infectious remnants of a viral infection. After examining the shapes and sizes of these nanometer-sized particles, the team concluded that most of them resembled viruses belonging to several known families, including the herpesvirus, retrovirus, and megavirus groups.
As the pattern was only detectable in a bleaching event, scientists found that harsh environmental conditions make the coral more vulnerable to infection. In fact, the amount of VLPs found in the coral just three days after bleaching began was two to four times higher than has ever been recorded in corals.
In a statement made by Rebecca Vega-Thurber, an assistant professor of microbiology at Oregon State University’s College of Science, the corresponding author of the study said, “This is bad news. This bleaching event occurred in a very short period on a pristine reef. It may recover, but incidents like this are now happening more widely all around the world. This research suggests that viral infection could be an important part of the problem that until now has been undocumented, and has received very little attention.”
Still, the viruses could not be definitively identified, which suggests that they could be new species. Consequently, researchers cannot be certain as to how harmful these viruses may be, although they suspect that they could prove dangerous in particularly high concentrations.