Knowledge for children: Coral reef

The four explorer friends love to race through the water and discover new things. After removing a lot of rubbish from the seabed, they reach a very special destination on their expedition: a large coral reef. It glows in many colours – red, blue and yellow – and resembles a rainbow. Small fish frolic among the corals, playing hide and seek or searching for food. In addition to fish, many other sea creatures live in the reef, such as seahorses, starfish, sea snails and small crabs. They all feel safe there because the corals give them protection and a home.

What exactly are corals?

Corals are animals. They live in groups in a fixed location in the water, which is called a "colony". Most corals live in the sea. All corals belong to the phylum Cnidaria, as do jellyfish and many other animals. The best known are stone corals, which can form coral reefs. Corals are beautiful to look at. Many of them are very colourful and therefore popular with divers. However, corals are even more important for nature: around a quarter of all marine fish live among corals. They find protection there and raise their eggs and young there. Corals only like a very specific temperature. As soon as it gets too warm, they die. They then lose their colour and only their white limestone skeleton remains. This has been happening more and more often in various places recently. One likely cause is climate change caused by humans. This is because it raises the temperature of the oceans. The large amounts of carbon dioxide that humans release into the atmosphere are making the oceans more acidic. This makes it more difficult for corals to build their skeletons. When corals die, many animals lose their habitat. Half of all coral reefs around the world are seriously threatened and many have already been destroyed.

What can you do on a small scale to combat coral bleaching?

Every person can also contribute to protecting coral reefs every day by adopting a sustainable lifestyle.

• Cycle more often, travel by bus and train, and eat less meat to reduce CO₂ emissions.
• Avoid plastic waste and microplastics that could end up in the sea.
• Travel, dive and snorkel responsibly.

The explorer friends realise how important the corals are. They form the garden of the sea. When the corals are doing well, the fish, turtles and many other animals can also live healthy and happy lives. With this knowledge, they swim on – full of hope that the children on land will also help to protect the sea and the corals.