In a new study led by scientists at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science and the Institute of Evolutionary Biology (IBE: CSIC-UPF) in Barcelona, researchers have discovered a single-celled microbe that may help corals survive ocean-warming events like bleaching. Publishing their findings in the journal Environmental Microbiology, the team found that the abundance of certain protists within the coral microbiome (the diverse community of microorganisms that live within coral) can inform scientists as to whether a coral will survive heat stress.
Collecting coral samples from across the Mediterranean to analyse their microbiome and conduct heat-stress experiments, the international team amplified and sequenced two types of rRNA to look at the bacteria and protists found in the microbiome of one species of soft coral, the violescent sea-whip (Paramuricea clavata), before subjecting them to a natural heat-stress in the lab to examine signs of mortality. They found that a group of parasitic single-celled protists called Syndiniales are more common in corals that survive heat-stress.
“This is the first time that a non-algae microbe has been shown to influence the ability of corals to survive a heat-stress event,” said the study’s senior author Javier del Campo. “As corals face more and more heat-stress events due to climate change, a better understanding of all the microbes that may influence survivability can inform conservation practitioners as to which corals they should prioritise for intervention.”
[image: The violescent sea-whip (Paramuricea clavata) is an important architect of the Mediterranean temperate reefs that is currently threatened by mass mortality events related to global warming. Credit: Parent Géry, via Wikipedia Creative Commons Attribution-Share Alike 3.0]