LONDON: Some species of tropical coral will find it difficult to recover after the yearly mass bleaching events predicted to occur later this century, suggests a new study.
The findings come from the first controlled experiment to look at the effects of annual bleaching on corals, reported in the Royal Society journal Proceedings B.
While the study suggests some species of corals can survive heat stress of a few weeks, the researchers warned this might not be the case for longer bleaching events.
And, even if some coral species do survive, the loss of others will mean less diversity on reefs which will have flow-on effects, they said.
“A lot of the diversity of other animals that live on coral reefs is based on the fact that you have a very three dimensional reef structure which is made up of different sizes and shapes of coral,” said lead researcher Dr Verena Schoepf, a marine biologist from the University of Western Australia.
“If there are only a few shapes or sizes of coral left then that will have cascading effects on all the other organisms … because there will be less habitat.”
Coral bleaching occurs when sea temperatures rise 1 or 2 degrees above maximum summer temperatures in a given location.
Sometimes water temperatures remain high for a few weeks, but in other cases months.
This causes coral to expel the photosynthetic algae they rely on for the bulk of the food, which slows or stops the coral’s growth and bleaches it of colour.
