The Great Barrier Reef. It is the largest marine ecosystem in the world which houses nearly 600 different species of coral, 1625 species of fish, 133 species of sharks and rays and more than thirty types of dolphins. But never – ever – has this « Manhattan of the oceans » been so threatened.
« Most people stare up into space with wonder. Yet we have this almost alien world on our own planet. », as Richard Vevers said. This may be the best introduction that the documentary « Chasing Coral » could’ve had.
In this special article dedicated to the urgent preservation of corals, you will encounter shocking information which most human beings ignore. In other words, you will learn more about the sad reality that affects our planet’s oceans.
What are corals?
Corals are marine animals made up of thousands of tiny members called « polyps », that are also living beings. Each polyp is a small circular mouth surrounded by tentacles. The polyp has microalgae in its tissues, which pile up by thousands in one cm2 . These small algae carry on photosynthesis, which allows the coral to nourrish itself.
Most coral reefs consist of hard corals, but we can all still find soft corals, like the anemone, where Clown fish live.
Coral bleaching, a critical situation
It was in the 1980s that scientists began to take an interest in a strange phenomenon called « bleaching ». Large groups of corals bleached in just a few weeks and no one understood what was going on. After a lot of research, they realized that it was not a any kind of disease, but that the only thing that made the corals bleach was the increasing water temperature (two degrees Celsius at the time).
People often think that global warming is a problem mainly related to the air temperature… But it’s totally wrong! Indeed, for the oceans, it’s like a change in a human’s body temperature. Just try to imagine that the temperature of your body increases by one or two degrees. You can survive from one to two weeks maximum, but after a while – and without any medication – it would be fatal. Well, this is the exact situation that occurs in the oceans right now, as you read this article.
Coral bleaching is actually a response to stress, just like human beings are acting when they have fever. If the temperature starts to rise a little, the corals will start to bleach while we start to get very hot or very cold. The polyps, which constitue the « feeding machine » of the corals, are disrupted. The underwater animal feels that a part of itself doesn’t operate normally, exactly as if a bacteria attacked the human body. Do you know what happens when a bacteria is found in our body? Here’s the answer: our body tries to get rid of it as soon as possible and that’s exactly what corals do. They are trying to get rid of those plants that do not work properly and keep almost nothing left of their polyps. They find themselves deprived of their main nutritive source and end up starving.
THE DEATH SUFFERED BY THE CORALS:
Increased water temperature due to human pollution
Corals try to get rid of what « could work badly »
They lose their main source of nutrition and end up starving
How is ocean water heated?
Well, it’s a very simple phenomenon to explain: when we are burning fossil fuels, such as gas or coal, greenhouse gases such as carbon dioxide (CO2) escape into the atmosphere and remain in suspension in this one. CO2 has the property of keeping heat. Yet, what people are unaware of is that 93% of this heat is absorbed by the oceans, which is considerable. If the oceans did not absorb this heat, the average temperature on Earth would rise to 50 degrees Celsius, knowing that today’s average temperature is 14.4 degrees Celsius.
It’s not too late for coral reefs. We managed to solve many problems in the past… Why can’t we do the same with this one?
To learn more about coral bleaching, watch the fantastic documentary « Chasing Coral. Here’s the trailer:
To watch more imagery of the beautiful coral reefs that we are trying to save, click on this link (all the pictures are coming from The Ocean Agency & the International Year of the Reef’s websites*): IYOR 2018 imagery
*Please note that their imagery is free to use for non-profit projects.