Some corals are creating a 'sunscreen' to protect themselves from rising sea temperatures, a study by scientists at the University of Southampton (UK) said.
Many corals introduce algae into their cells to help them both grow together. However, even a 1 degree Celsius increase in temperature can cause problems for the balance causing algae to be lost. This makes the coral's frame exposed to the sun often leading to the death of corals. This phenomenon is called coral bleaching.
The researchers found that corals emit color to try to encourage algae to return.
The bleaching of coral occurs when the water temperature reaches 30 - 31 degrees Celsius due to climate change. It will have to release symbiotic algae inside its tissues, which serve as food sources. If warm water lasts longer than a few weeks, corals will die.
Scientists from the coral reef laboratory of the University of Southampton have just published a report in the journal Current Biology. They have observed that some corals create a "sunscreen" with a color layer during a little warming period or for a short time.
Colorful coral reefs in New Caledonia waters in 2016.
The team believes that these bright neon colors are emitted to encourage algae to return. Professor Jorg Wiedenmann explained: "Our research shows that the creation of this color consists of a self-regulating mechanism, called an optical feedback loop , with the participation of symbiotic partners (san). coral and algae) ".
"In healthy corals, most of the sunlight is absorbed by the photosynthetic pigments of symbiotic algae.
When corals lose this symbiotic, excess light will enter the tissue, reflected by the white coral bone. However, if the coral cells are still able to continue performing at least some of their normal functions, despite the environmental stress that causes bleaching, an increase in internal light levels will promote The creation of colorful optical pigments.
This sunscreen will promote the return of symbiotic " - Professor Jorg Wiedenmann adds.
The Great Barrier Reef's reefs underwent two consecutive bleaching events in 2016 and earlier this year, raising concerns among experts about the viability of coral reefs under global warming. bridge.
Dr Cecilia D'Angelo, a lecturer in coral molecular biology at the University of Southampton, added: "Unfortunately, recent global coral bleaching events caused by unusually warm water have caused many corals to die, Many coral reefs around the world struggle to survive. "
Recently, scientists announced a way to find corals to counteract the effects of warmer seawater by method, raising new strains of microalgae and exposing them to warmer temperatures for four years.
They then injected each microbe with each strain of coral algae and exposed them to temperatures of up to 31 degrees Celsius for a week. They found that 3 out of 10 strains of algae protected coral from bleaching.