Although beautiful to look at, the photo documents a menacing development: coral bleaching as a global consequence of climate change. Due to the increased water temperatures and the increasing salt content, the coral reef ecosystem is exposed to greater stress. This also brings a vital partnership out of balance. Because the corals lose their symbiosis partner, the Symbiodinium. This alga provides photosynthesis and thus food for the corals. If the symbiosis disturbed, it comes to coral bleaching. What remains is the holobiont, the translucent skeleton of the dead coral.
Researchers led by Michael Ochsenkühn of the Red Sea Research Center at King Abdullah University of Science and Technology in Thuwal, Saudi Arabia, have now researched molecular mechanisms in the Red Sea that could help reduce coral bleaching. The coral reefs in the Red Sea represent a suitable model ecosystem because the symbionts have a very high temperature tolerance. In addition, the salinity in the Red Sea is very high.
The researchers discovered how the sea creatures survive in these conditions: Due to the high salt concentration, the Symbiodinium algae produce a substance that influences the osmosis in the cells of the algae and corals. This makes the cnidarians more resistant and supports the photosynthesis abilities of the algae, the researchers noted.
Ochsenkühn and his colleagues hope that their research will help stem the death of coral. Their previous results have been published in the journal Science Advances . display
Photo: Anna Roik© science.de - Ruth Roebuck / Karin Schlott