Algae helps coral cope
Australian scientists have discovered how algae help coral cope with climate change.
A species of algae called dinoflagellates that live and reproduce naturally in some types of reef coral and might increase its heat tolerance, according to Madeleine van Oppen, a senior research scientist at the Australian Institute of Marine Science in Townsville.
"A mechanism exists in coral that allows them to rapidly change how well they can cope with environmental conditions," Dr Van Oppen said.
"The algae inside the coral tissues use sunlight to make the energy and a large part of this energy or food is available to the coral.
"It leaks out of the algal cells into the coral tissues, so the algae actually works as sort of solar panels."
Some corals obtain up to 90 per cent of their food from the algae.
But scientists have not yet quantified to what extent the algae could stop coral bleaching or if the possible introduction of more dinoflagellates would have unwanted side effects.
"You may increase your heat tolerance but it's at the expense of other characteristics such as growth and also reproduction," Dr Van Oppen said.
"If a cyclone comes along, they (the corals) may have trouble recovering from that if they grow very slowly."
Dr Van Oppen said making life more difficult for coral was the fact that it took up different kinds of algae early in life.
But the dominant species of algae within the coral could change in a process known as shuffling.
"We don't fully understand the implications of this shuffling," she said.
"It may enhance one trait but it might be at the expense of another and that's an area we are now going to work on to better understanding that, so we will be able to better predict what might happen to corals over the next couple of decades."
Scientists have predicted that colourful corals which make up the Great Barrier Reef will fall dramatically and die in numbers by 2050 because of warming seawater bleaching them.
But existing models for coral bleaching did not take into account any of the mechanisms for acclimatisation and adaptation of corals, she added.