Researchers found that bleached coral fragments can fully recover within eight weeks if they form a tissue bridge with healthy fragments from the same genetic individual.
Scientists have demonstrated that bleached coral can be rapidly restored in a laboratory setting by placing it in direct contact with a healthy fragment. The findings, reported in Science Advances on 14 October, suggest that physical contact allows for the transfer of symbiotic algae, potentially offering a method to reverse coral decline.
Coral bleaching occurs when rising sea temperatures cause corals to expel the symbiotic algae, known as Symbiodiniaceae, that live in their tissues and provide them with nutrients. Without these algae, corals are likely to starve and die.
The study focused on the coral species Pocillopora damicornis. Researchers prepared ten pairs of fragments from the same animal, with each pair consisting of one bleached and one healthy fragment. Five pairs were placed in contact, while five were separated by a few millimeters.
According to the study, the touching pairs showed significant recovery. "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," says Danny Collins, a PhD student at Stanford University and co-author of the study. By week two, the symbiont population in the recovering coral was doubling every four days. The bleached coral in the touching pairs fully recovered within eight weeks.
In contrast, the bleached fragments in the separated pairs died after 20 weeks. The research indicates that the recovery is driven by the formation of a tissue bridge between the two fragments, which enables the transfer of symbionts.
The study highlights that this recovery mechanism is strictly limited to genetic matches. Using high-powered microscopy, the team observed that tissue bridges only formed between fragments taken from the same genetic individual, referred to as a genet.
Fragments from different species, or even different animals of the same species, did not fuse together. Consequently, these mismatched pairs did not nurse the bleached piece back to health. Once a bleached branch had been in contact with a healthy branch for a week, it could fully recover on its own, even if subsequently separated.
The rapid recovery observed in the lab contrasts with the slower recovery times seen in other studies of coral recovering naturally in the wild. Fiorenza Micheli, a marine ecologist at Stanford University’s Center for Ocean Solutions and a co-author on the study, notes the potential for broader applications.
"This incredible new result — that fast and full recovery is possible in bleached coral — can inspire solutions that eventually may be scalable," says Micheli.
As rising sea temperatures continue to stress marine ecosystems, understanding how corals can recover from bleaching is critical for conservation efforts. This research identifies a specific biological mechanism—tissue fusion between genetically identical fragments—that could inform future strategies for restoring coral reefs.
Sources
This article was drafted with AI assistance and checked against the sources above. Company claims are reported as claims. Cover image is AI-generated.
The day's checked news, by email
One short email a day with the top stories. Free, and you can unsubscribe in one click.
Or follow for the latest news:
No comments yet. Start the discussion.
ScienceTrending
A joint expedition by Purdue University and the Archaeological Legacy Institute found no conclusive evidence that Amelia Earhart’s plane wreckage is on Nikumaroro Island. The team determined a suspected object was likely debris from trees.
Researchers at the Max Planck Institute for Radio Astronomy identified a second jet in galaxy Mrk 501, suggesting a binary black hole system that could merge within a century.