Bleached coral recovers in days by touching a healthy neighbour
Bleached corals thrive within days when touching healthy neighbour
Rising sea temperatures strip corals of the symbiotic algae that feed them, leaving them bleached and starving. In a Science Advances study, Stanford researchers placed bleached fragments of Pocillopora damicornis against healthy fragments from the same individual. The two fused via a tissue bridge, and the bleached coral recovered within eight weeks — symbiont populations doubling every four days. After just one week of contact, it could recover alone. Separated fragments died.
We were blown away when we watched the colour of the algal symbionts transfer over to the bleached coral, reviving it in a very short period of time.
- skew-aberration
Coral gets its color from algae called zooxanthellae, which it depends on for photosynthesis.
Bleaching is actually due to the coral expelling those algae. Bleached corals are not dead, and remarkably they can not only let the algae in again but can also select a different algae species to cultivate (changing colour in the process)!.
This is thought to be a deliberate survival strategy to optimize the species of algae under different conditions (Adaptive Bleaching Hypothesis).
Bleaching is caused by the same stressors (like high temperature) which kill coral, but bleaching itself is not death of the coral.
- nomel
> This incredible new result
Only if you've never talked to anyone remotely involved with propagating coral, including those in the saltwater fish-tank community!
- ghastmaster
Of note: This only occurred for fragments taken from an individual of the same genetic makeup(genet: basic meaning is they are a colony). Presumably, it would be difficult to recreate this at scale in the wild. I did not read past the free to read portion of the article that mentions scaling this is possible. I am curious about the methodology of that.
I find it strange that the first observance of this was a year ago, especially given how rapidly it occurs. Coral bleaching has probably been studied since the 80s when major events started being noticed. If Stephen Palumbi is reading this, I would love to read why you think it took so long.
edit: I would wager this is only the first published observance.
- anakaine
Having been a diver on the Great Barrier Reef numerous times, the scale of bleaching events means that there is often no non-bleached neighbour for vast distances. Healthy propagation rarely occurs before the brown sludge sets in, then its game over.
- Okkef
Only if they are clones - genetically identical. So not much use in practice, unfortunately.