Have you ever wondered how coral reefs are made? The formation of coral reefs is a pretty interesting phenomenon and they provide a huge and varied ecosystem that thrives under the water. Coral reefs are often referred to as the “rainforest under the sea” and almost a quarter of all underwater species call the coral reef home. For the most part reefs are found in the tropics near the shoreline although there are some reefs in the deep sea. Let’s look at how they are made.
The First Stages of the Reef
A reef begins when coral larvae attach itself to the rocks and soil near the coast. The larvae need to attach themselves in an area where there is enough sunlight filtering through the water and these larvae turn into polyps which excretes calcium carbonate that forms the exoskeleton. The calcium carbonate provides a substrate for even more polyps to attach themselves eventually forming a coral reef. At the same time algae also attaches to the structure and so do other plants and that makes the reef stronger. The initial reefs are referred to as fringing reefs, over time the calcium carbonate in the reef converts to limestone because of pressure.
Eventually the fringing reefs come together and form a border of sorts along the coast with the calcium carbonate luring in more polyps and the space eventually becomes filled in. It can form a ring around an island and a line along the coast, the colors and formations are absolutely beautiful. Since they are in relatively shallow water the sunlight helps the reef to grow. The biggest reef is The Great Barrier Reef in Australia here is a closer look at it.
Coral reefs have a huge and complex ecosystem that is absolutely fascinating. There is a huge variety of marine life including fish, algae, sponges and loads of other species that rely on the reef for food and shelter. The bigger the reef the more species that you will find in there. Let’s look at some of the more common species found in a reef.
- Sponges: These act as filters for the sediment within the reef and are crucial to the function of the reef. They take large large globules and turn them into much smaller particles that can be then absorbed by the reef.
- Fish: There are more than 5,000 different kinds of fish that live in the coral reef, fish are a vital part of the food chain and they live within the corals.
- Invertebrates: These are the sea urchins, slugs and anemones and if you ever going diving near a reef you will see plenty of them.
Coral reefs are a complex and biodiverse ecosystem that are in danger because of pollution and man invading their natural habitats. We need to bring awareness to the issue and make sure that we protect this delicate yet vital part of our oceans.