Understanding Coral: The World’s Underwater Gardens
It’s coral reefs awareness week so I thought i’d explore these fascinating creatures.
What do you know about coral reefs? Unless you’re a marine biologist or have a huge interest in the ocean, probably not a lot.
For most of us, coral reefs are essentially underwater gardens. Pretty places for fish (like Nemo!) to live and call home and for humans to snorkel and scuba dive. You aren’t wrong, but there is so much more to coral reefs than their beauty and the fact that they provide shelter to Nemo fish all kinds of sea life.
One of the biggest misconceptions about coral is that it is not a rock or a plant, but actually an animal. Even stranger? While we tend to think of coral as one being, it is in fact made up of thousands of tiny creatures called polyps. The polyps work as a colony; constantly growing and expanding over time which is why some of the world’s coral reefs are millions of years old. Of course, growing a coral reef takes time and often need hundreds (or millions) of years to become proper, large reefs. Corals grow at different rates; some as slow less than 2mm of growth per year, while others may grow up to 10cm in a year.
On their own, the polyps are transparent. Coral reefs get their vibrant colors from billions of colorful zooxanthellae algae which work together with the polyps in a symbiotic relationship to make coral reefs as we know them. The algae, however, start to leave when stressed with factors including temperature changes and pollution, which results in what we refer to as bleaching.
While it is possible that the algae may return and regenerate the coral reef (over a period of many years), these effects also act as stressors on the polyp colonies which, if killed, will kill the entire coral reef. This is happening to many reefs around the world, despite the best efforts of many Eco Projects, including the largest coral reef: Australia’s Great Barrier Reef, which stretches over 2500km.
Coral reefs are often considered to be tropical, but they can exist all over the world. The most visited and commonly seen reefs are located in warmer, shallow waters that get plenty of sunlight. However cold water reefs exist as well, in the United Kingdom, Canada, and even Scandinavia in waters with temperatures as low as 4 degrees Celsius. Interestingly enough, the oldest coral reef that has been discovered by scientists is located in Poland’s Świętokrzyskie Mountains and is approximately 390 million years old.
Coral reefs provide home and shelter to 25% of all marine life; enough to rival the tropical forests of the Amazon. Yet, despite the fact that this makes coral reefs one of the most important eco systems in the world, the reefs themselves make up for less than a quarter of a percent of the world’s marine environment. Thanks to several factors including pollution, over fishing, climate change, coral mining, and destructive fishing practices, this tiny fraction of a percent is growing even smaller.
Want to help? Consider joining one of Eco-Companion’s marine conservation tours in the Azores, Madagascar, or Indonesia where you can enjoy the beauty of the coral reefs and help make a difference. Also be sure to educate yourself and others on proper marine tourism; this mean no touching or standing on coral reefs. And, of course, share this information to help
Find out more about Eco Diving in the Azores.
Sign-up for our Marine Conservation Project in Albufeira.