What is Coral Bleaching?
Coral Bleaching Meaning - You might have heard about scuba diving. It's a very beautiful and thrilling experience. Isn’t it? The beautiful and coloured corals can be seen under the sea. Do you know how these corals look so beautiful? They look so beautiful because their stunning colours come from marine algae called zooxanthellae. These algae live inside their tissue. The function of these tissues is to provide food to the corals. The corals can grow and reproduce with the help of these algae.
When the corals are disturbed by external factors such as pollution or heat, they start expelling the algae. This leaves just the ghostly and transparent skeleton behind known as coral bleaching. When the algae leave the corals, it keeps fading until it looks like it is bleached. So, if we have to write the coral bleaching definition, we will write as - The leaving of algae from the corals, leaving the coral reef dead is called reef bleaching.
What Triggers Coral Reef Bleaching?
One of the most common coral bleaching causes is the change in the climate. We know that at present, global warming is the greatest threat to life on Earth. Because of global warming, planet Earth is warming up - the seas are warming up. This heating of ocean waters is one of the major causes of coral bleaching. There are other causes too such as pollution, overfishing, low tides, too much sunlight, and coastal development that causes coral to bleach.
[Image will be uploaded soon]
Effects of Coral Reef Bleaching
Coral reef bleaching is a threat to the environment. When these corals die, they never or rarely come back. The number of corals becomes limited and they struggle to reproduce. As a result, the coral family is extinguishing.
Coral Bleaching’s Impact on Wildlife
Coral reefs are the support system for many biodiverse ecosystems. They are the source of survival for many species such as sea turtles, fishes, crabs, sea birds, jellyfishes, starfishes, shrimps, and many more. They provide shelter, spawning grounds, and protection to many species. Coral Reefs also are an important part of ocean food chains. As the coral reefs are destroyed because of bleachings, these marine lives and the ocean food chain gets disturbed and some species may face extinction.
[Image will be uploaded soon]
Coral Bleaching’s Impact on Humans
Coral reefs are a support system for humans living in coastal areas. They have an impact on people’s safety, food, and livelihoods. The Coral Reefs act as natural barriers to absorb the storm surges and the force of waves keeping the people of coastal areas safe. If there are no coral reefs, we have to build a seawall manually which will be very costly, will have fewer effects, and will be damaging to the environment. Coral bleaching also impacts fishes and the people who rely on fishes for their source of income. Also, coral reef tourism is a source of income for many individuals and also contributes to a nation’s economy.
Do You Know?
The largest and richest coral reef in the world is the Great Barrier Reef. It has been protected since the 1970s. The fish population tripled after the marine sanctuary for Apo Island in the Philippines was created in the year 1982. The marine protected areas, where fishing and fishing methods are regulated, are called Reefs at Risk Revisited. The bleached great barrier reef is a threat to our marine beauty and also to humans.
How to Stop Coral Bleaching and Protect Coral Reefs?
Either we live in coastal areas or far from the sea, we can do our part to protect the coral reefs and stop coral bleaching. Whatever we do on the land, in some ways affects the water. So, we should take care of our activities to stop the pollution which will eventually impact global warming and other activities too so that the coral reef bleaching can be stopped.
Here are a few to-do lists to stop coral bleaching and protect the coral reefs:
While visiting the coral reefs, we should avoid touching them or disturbing them anyway. If we make any contact, it can damage the corals and may even kill them.
The cosmetics that we use may harm the coral reefs. So, we should avoid cosmetics while visiting them.
We should be careful while throwing the trash as marine trash is very harmful to the coral reefs. We should never throw plastics and other nonbiodegradable things near the beach or in the water to stop debris pollution.
The fertilizers that we use for the plants wash away in the water which harms the marine animals and the coral reefs. We should minimize the use of fertilizers.
We should try to reduce the emission of greenhouse gases. The emission of greenhouse gases causes ocean acidification and increases ocean temperature. This becomes one of the main causes of coral bleaching.
FAQs on Coral Bleaching
1. What exactly is coral bleaching?
Coral bleaching happens when corals get stressed by changes in their environment, especially warmer ocean temperatures. This stress causes them to expel the tiny, colourful algae called zooxanthellae that live inside their tissues. Since the coral's skeleton is naturally white, it looks like it has been bleached.
2. What are the main causes of coral bleaching?
While several factors can stress corals, the primary cause of widespread bleaching today is rising ocean temperatures due to climate change. Other stressors include:
- Pollution from land, such as agricultural runoff and plastic waste.
- Too much direct sunlight or exposure to the air during extreme low tides.
- Changes in water chemistry, like ocean acidification.
3. Does coral bleaching mean the coral is dead?
No, not necessarily. A bleached coral is still alive, but it is under severe stress and is much more vulnerable. Think of it as being very sick. If environmental conditions return to normal quickly, the coral can regain its algae and recover. However, if the stress continues, the coral will starve and die.
4. Why is coral bleaching a serious problem for the entire ocean?
Coral reefs are like underwater cities that support about 25% of all marine life. When corals bleach and die, the entire ecosystem collapses. Fish lose their homes and breeding grounds, coastlines lose a natural barrier against storms, and communities that rely on fishing and tourism suffer.
5. How does a bleached coral actually recover?
Recovery is possible if the source of stress, like high water temperature, goes away. Surviving zooxanthellae in the coral's tissue can reproduce, or the coral can capture new algae from the surrounding water. This process is very slow and can take several years, during which the coral is weak and susceptible to disease.
6. What is the difference between coral bleaching and ocean acidification?
Coral bleaching is when corals expel their colourful algae due to stress, primarily from heat. Ocean acidification is a separate problem where the ocean absorbs too much carbon dioxide (CO2) from the atmosphere, making the water more acidic. This makes it harder for corals to build their strong, calcium carbonate skeletons in the first place.
7. What are some real-world examples of major coral bleaching events?
One of the most famous examples is the repeated mass bleaching of the Great Barrier Reef in Australia, with severe events happening in 2016, 2017, and 2020. Similar widespread bleaching has been observed in coral reefs across the globe, including in the Caribbean Sea and the Indian Ocean, highlighting that this is a global issue.
