Coral reefs provide food and habitat for large numbers of marine plankton and fish in the offshore waters, and massive coral bleaching (death) around the world in recent decades has caused serious problems for marine ecosystems. Based on this situation, many teams around the world have tried to work on coral populations, such as artificially cultivating corals and transplanting them into the ocean, but the efficiency of such transplants is not as high as that of naturally propagated corals.
The problem is that because corals are not heat-resistant, global warming is the main culprit of coral bleaching. Therefore, even transplanting corals does not seem to be able to save coral reefs from dying on a large scale, so a research team started with the heat resistance of corals.
The Coralassist Laboratory from Newcastle University in the UK has successfully bred the world's first heat-resistant coral. By selectively cultivating adult corals, researchers have obtained varieties whose heat resistance can be increased by several degrees Celsius.
The researchers actually selected two types of corals. The first one can be exposed to higher temperatures in a short period of time (10 days) (heat resistance increased by 3.5°C compared with conventional varieties), and the other has lower tolerance but can be exposed to higher seawater for a long time (1 month, heat resistance increased by 2.5°C).
Another good news is that research has found that the offspring of these heat-tolerant populations can also continue to improve their heat tolerance, that is, the heat tolerance of their offspring will continue to increase to catch up with the increase in global sea temperatures.
Increased heat tolerance could theoretically improve coral survival rates, which could help restore coral populations in certain areas, provide more habitat for marine life, or slow down the current damage to coral populations caused by global warming.
Unfortunately, the researchers clearly mentioned in the paper that although they have obtained varieties with higher heat resistance, the increase of 2.5 to 3.5 degrees Celsius still puts great pressure on the restoration of coral reefs, because this increase in heat resistance is insignificant compared with the expected rate of global warming in the future.
Liam Lachs, a postdoctoral researcher at Newcastle University who is leading the project, said rapidly reducing global greenhouse gas emissions is an absolute must to mitigate global warming and give corals a chance to adapt.
Finally, the paper also mentioned that although the selected varieties did improve heat resistance in the experimental environment, it remains to be seen whether they can achieve the survival and reproduction of the adult community in the real marine environment.
Additional Information:
Paper address: https://dx.doi.org/10.1038/s41467-024-52895-1
"Selective breeding enhances coral thermal tolerance to marine heat waves" was published in the journal Nature Communications on October 14, 2024