The researchers from the Australian universities has identified genes that allow some algae living in corals to tolerate higher ocean temperatures than others. The problem of coral bleaching is becoming more urgent throughout the world, so Australian scientists decided to study it on a genetical level. The genes could act as markers to understand the risk of coral bleaching in different areas of tropical reefs including the Great Barrier Reef.
According to the latest research of scientific team led by the University of New South Wales (UNSW), tropical corals cannot survive without the Symbiodinium algae that live inside them. These photosynthetic organisms supply the corals with all their food, more than 90 percent. UNSW specialists say that increased water temperatures stress the algae, provoking them to produce an excess of toxic substances, which called reactive oxygen species. As a result of intoxication, damage both the algae and the corals.
In fact, increasing the temperature is the main reason of bleaching the corals and their starving to death. That’s very bad for marine ecology and size of Great Barrier Reef, notes student Rachel Levin. On a genetical level, there have some reactions too. “We found they can switch on genes to produce proteins that neutralize the toxic chemicals,” explains Levin, whose article on coral bleaching was published in the Molecular Biology and Evolution.
Coral bleaching research was led by the UNSW Professor Peter Steinberg, Director of the Sydney Institute of Marine Science, and Professor Madeleine van Oppen of the Australian Institute of Marine Science and the University of Melbourne. Their heat-stress experiment conducted in the laboratory, showed that tiny algae have more genes than humans do. That’s why the algal genes are able to activate or de-activate needed reaction to the temperature’s difference.