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A laboratory in Dubai: This is where Ahmed Hamdy looks after particularly sensitive animals. He works in a coral farm. The goal: to breed coral species that are as resilient and heat-tolerant as possible, which can later be planted in damaged coral reefs.
Ahmed Hamdy, coral farmer:
»We control the corals' environment, which gives them the opportunity to better prepare themselves against climate change. With this system, which is a closed circuit, we can control the temperatures, the light intensity and the waves. “So we create an environment that makes the corals stronger than regular corals so that they can actually survive in the ocean.”
The growth of these corals can be increased up to 50 times compared to the growth in nature, as this time-lapse video proves. Around 1,000 pieces of coral are stored in the start-up's laboratory. These are repeatedly cut into several small pieces. The result: All parts of the coral grow back - and smaller pieces grow back particularly quickly.
Ahmed Hamdy, coral farmer:
»This is the cutting machine that we use to cut the corals. Now we're going to cut off a small piece so we can stick it into our plugs that we use to grow the corals."
The start-up uses a plug-in system to store the coral fragments.
Ahmed Hamdy, coral breeder:
»This is the basis that we use for the growth of the corals. We have already applied the glue, now the coral is glued to the plug.«
In addition, the water temperature in the water tanks is controlled and gradually increased so that the corals can slowly adapt. After six to twelve months they are large enough and are relocated to the sea.
But why are corals important? A quarter of all marine animals live in reefs. They are also important for coastal protection and can mitigate storms. And people from coastal regions rely on coral reefs as a tourist attraction.
But around the world, sensitive ecosystems are doing worse and worse. If coral death continues at this rate, up to 90 percent of all coral populations could be dead by 2050. The reasons for this include overfishing, but also the increasing plastic waste in the seas.
Jessica Reichert, marine biologist:
»But the biggest stressor that we have definitely seen in recent years is climate change and the increasingly frequent and severe heat waves. That's probably why we're now at the beginning of the fifth mass bleaching event in just eight years."
Corals are tiny little animals that build a limestone skeleton around their bodies, which forms the basis of a reef. They live in symbiosis, i.e. in community, with small single-celled algae. These organisms use sunlight to convert carbon dioxide into sugar, providing the corals with the nutrition they need.
However, if the water becomes too warm, the algae produce more pollutants instead of nutrients. The coral repels the vital algae. Then only the white limestone skeleton is visible and the coral fades. If new algae do not settle soon, the coral dies and practically “starves”.
The start-up in Dubai wants to take action against this. Coral reefs are to be rebuilt using small pieces of coral in breeding stations. According to its own information, it will have planted 30,000 corals in the Caribbean Sea in 2023.
It's not the only company taking this approach. There are similar projects around the world. In Australia, for example, ten million new, heat-tolerant corals are to be released every year by 2030.
However, Jessica Reichert from the Marine Biology Institute in Hawaii is skeptical as to whether this can work on a large scale.
Jessica Reichert, marine biologist:
“But you can only ever improve reef health very locally. If you think about it, the Great Barrier Reef is about the size of Italy, if we imagine that we now want to repopulate Italy or that size with small coral fragments. It’s just hard to imagine that we can do that.”
Therefore, further approaches are currently being researched. For example, an acoustic process that was tested in the Caribbean. The idea behind it: Corals can reproduce in different ways, including through egg and sperm cells that meet and fuse. This produces small larvae, which then attach themselves and develop into adult corals.
In the study, underwater speakers are intended to imitate the hustle and bustle of the underwater world. If coral larvae hear the sounds of an intact ecosystem, they are more willing to settle on already damaged reefs - something they would otherwise do less.
Jessica Reichert, marine biologist:
»How well this works is not entirely clear. This simply needs to be tested further. Here we are at the very beginning. Of course, it's always difficult to carry out such experiments in the reef because there are many factors that have an influence from outside.
Saving corals is a race against time. As heat waves increase, the interval between them is becoming smaller and smaller; it is currently around two to three years. This is not enough for a coral reef to fully recover.
Jessica Reichert, marine biologist:
»We will most likely lose some corals, others are resistant. Unfortunately, we often lose those that are very branched and very complex. And as a result, we are likely to lose the structural complexity of coral reefs. It is very likely that the corals will change their location, that they will disappear from the particularly hot regions and that we will increasingly be able to find many more coral reefs in the slightly colder regions.
The so-called “rainforests of the seas” are not doing well. If they become unbalanced, it could have drastic effects on the entire marine ecosystem. Approaches such as working with coral fragments work in a local area, but cannot be used to combat the mass of damaged corals. In order to save coral reefs in the long term, climate change would have to be mitigated.