…some corals survive
Research led by my team on Caribbean and Hawaiian corals shows that corals can use one or more of these coping strategies to survive single isolated bleaching events. However, corals appear to need more than one year to fully recover from bleaching stress. So how will coral survive as bleaching events become annual occurrences, as climate change continues to raise ocean temperatures? Can corals rapidly adapt to annual bleaching?
My team has found that the coping strategies of Caribbean corals that recover quickly from bleaching in one year may not be a good predictor of their capacity to recovery from a bleaching event the following year. Basically, even if corals made it through a tough time last year, they might not have what it takes to hang on through another challenging year now. To fully recover from annually recurring bleaching stress, the best coping strategies for corals boil down to just two: corals need to have lots of energy reserves and be able to shuffle their algal types.
Healthy finger coral, close up.
Andrea Grottoli, CC BY-ND
For instance, we found that the mustard hill coral (Porites astreoides) was the least affected by an initial bleaching event but was the most affected by the second bleaching event. It didn’t have enough stored energy and wasn’t able to shift the types of algae it hosts. On the other hand, the finger coral (Porites divaricata) was hard hit by the first bleaching and slow to recover. But it was hardly affected by the second bleaching stress the following year because it had high levels of energy reserves and shuffled its algal types in response to both bleaching stresses. So the finger coral was able to rapidly adapt while the mustard hill coral could not.
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