Coral Bleaching
Coral bleaching is believed to be the process by which coral become stressed from surrounding change in conditions therefore losing their colour. However, it is slightly more complex than that.
What most people do not know is that coral is not actually a plant and so on its own it cannot function. Coral’s contain a plant within them called algae (zooxanthellae), which gives it not only its food, but its colour as well. Algae is a producer, it takes energy from sunlight and through the process of photosynthesis converts it into oxygen and glucose. This therefore provides the coral with food.
Coral and algae work in a symbiotic or mutualistic relationship. This means they both benefit from each other. Coral obtains food from the producing algae, while the algae finds protection and safety from the coral skeleton. The reason why coral can be many different colours is purely down to the type of algae they are home to. When there are no algae present the skeleton of the coral is revealed, and this is transparent but comes across as white hence the term coral bleaching.
When a coral becomes stressed it will expel the algae and it will eventually take another back in if conditions stabilize, or it will die. The reason for why coral does this is still unknown however the causes are not. Currently, the main reason for coral bleaching is believed to be a rise in water temperature however any disturbance in abiotic conditions can cause stress on coral. Coral is very sensitive and the smallest change in the abiotic environment can have a large impact. As mentioned before, if conditions stabilize then the coral may be able to take another alga, however when it comes to temperatures, they are not stabilizing, only increasing so therefore masses of coral are dying out at an alarmingly fast rate.
Above is am imaged showing bleached coral.
Below is a picture of health coral – an important note to add is that when I was looking for picture of colourful coral I had to search ‘healthy coral’ rather than just ‘coral’ this shows the point of destruction that we have reached.
Coral bleaching not only means we lose some of the most beautiful sights on Earth, but we lose life. We lose coral, algae and all the fish dependant upon it. The whole thing is a delicate system and this is main problem with any disturbance. It will not just have an affect on the one thing you are damaging, but the tens of other things dependant on it for survival. Once the knock on effect impacts one thing, it spirals downwards negatively effecting many other systems and food chains.
What can be done?
When it comes to coral reefs, the future does not look good. Most people believe that the damage that has been done has now gotten to a point a being irreversible. However, nothing is certain and all efforts help.
First of all, another reason for coral bleaching and death is sediment smothering. Sand and sediment can suffocate coral if it is in excess. Coral is adapted to this and has small tentacle like extensions that push sediment always from the ‘mouth’. However, it is not adapted for sediment in excess and if divers are kicking at the sand it will swarm around the coral and suffocate it. So educating tourist is an important part of helping with coral bleaching and destruction.
One important thing that is so easy to do but not carried out it is basic respect. It is so easy to not cause that damage if you take precautions. This needs to be taught to tourists in order to minimize damage to the reef.
Things need to change, and fast. If we as humans do not take the responsibility of taking care of our home the way we should, then we only have us to blame when it all goes bad. The way things are looking now, that is the direction we are headed if we do not make significant changes now.
https://lantaoldtown.com/things-to-do/ko-cheuak-closed-due-to-coral-bleaching