What is the cause of coral bleaching?

Coral bleaching is a phenomenon that occurs when corals turn white due to environmental stress. It is a recurring event that frightens marine biologists and raises serious concerns for marine ecosystems around the world.

When the water is too warm, corals excrete algae (zooxanthellae) that live in their tissues. As a result, the coral loses its vibrant color and becomes more susceptible to disease.

Corals have an obligatory mutual relationship with these algae. This means that organisms depend on each other to survive. From their products of photosynthesis, the zooxanthellae provide the coral with the nutrients it needs to survive, while the coral provides the zooxanthellae with carbon in return.

When lost, it is a great loss for the coral because these symbiotic algae provide 90% of the coral’s energy through the process of photosynthesis. Without zooxanthellae, the coral begins to lose its color and eventually takes on a shiny white appearance, hence the term coral bleaching. Coral essentially starves and dies without the necessary nutrients from the zooxanthellae.

Global warming is a major cause of coral bleaching, but other environmental factors also play a role. Corals can survive briefly without zooxanthellae, but since algae are their main food source, they cannot survive for long. Once the coral dies, it begins to decompose.

Another cause of coral bleaching is the lack of oxygen. This is due to an increase in the zooplankton population in a given area, most likely due to overfishing. Another less common but notable trigger is sedimentation. This occurs through sediment runoff from land into the ocean through rain and other bodies of water flowing into the ocean.

Additionally, La Niña or El Niño may also play a role by not only changing the water temperature but also bringing some silt/sand along with nutrients from the seafloor.

The main cause of coral bleaching is the stress caused by warmer water temperatures due to global climate change. Corals provide shelter for a range of marine organisms and also protect the coasts. Without coral reefs, marine life would likely abandon the area, which in turn could cause damage to marine ecosystems.

Coral reefs support approximately 25% of marine species. They are also a great benefit to the fishing industry as they attract a lot of marine life.

There have been three major coral bleaching events in recorded history, the first occurred in 1998, an underwater heatwave spread and killed 16% of the world’s corals. The second major coral bleaching event occurred in 2010, caused by El Niño.

The most recent coral bleaching occurred in 2015 and was caused by warming oceans. Warming oceans are a major threat to coral reefs. As mentioned above, the warming of the oceans is the main cause of coral bleaching. A staggering 93% of heat from climate change is absorbed by the ocean.

Reefs provide shelter for smaller fish and can be a source of food for others. Coral reefs are essential to the life of countless organisms and without coral, large numbers of these organisms would perish creating a much bigger problem.

The smaller fish can no longer survive without the coral reef, resulting in less food for the larger fish that feed on them. Around 100 million people around the world depend on coral reefs for their survival. With a decline in healthy coral ecosystems, there will be fewer fish, which are an important food source for many people.

Humans also depend on coral reefs for other economic reasons. purposes such as tourism. The impact of coral reef loss on the tourism industry is estimated at around US$10 billion to US$40 billion, followed by fisheries with a loss of US$7 billion to US$23 billion and the impact on biodiversity, losses between US$6 billion and US$22 billion cause US dollars.

Butterflyfish are fish that feed exclusively on coral polyps whose food source is disappearing. Butterflyfish also prevent algae from drowning corals, and if that population dwindles, the corals that are still alive could end up dying from too many algae.

Lobsters need coral reefs to protect themselves, especially when they molt when they are most vulnerable. These lobsters play an important role in maintaining a balanced ecosystem.

Crayfish are predators of sea urchins, feed on kelp forests, and can destroy them if predator populations are not controlled.

Dolphins and most whales are predators and all are carnivores. They survive by eating fish that depend on coral reef habitats. Any species lost to coral bleaching has the potential to affect the rest of the ecosystem.

Hawksbill sea turtles have become an endangered species and rely heavily on coral reefs for their food sources. Their diet consists mainly of sponges.

Sea turtles play a very important role in their ecosystems by supporting the nutrient cycle from ocean to ocean. land, maintain healthy seagrass beds, and balance food webs.

Studies have shown that whale shark populations declined in the 1980s and 1990s, possibly due to coral destruction. Many corals were destroyed during this time by humans and coral bleaching. While it’s not certain that these two are related, the timeframes suggest they are.

But what is the root cause of all this? Global climate change is caused by the increase in greenhouse gases, primarily carbon dioxide, being released into the Earth’s atmosphere. Carbon dioxide and other gases trap heat in the atmosphere, causing the earth to warm. As the earth warms, the temperature of the water rises, causing coral bleaching.

Humans are the main source of greenhouse gases produced by burning fossil fuels and released into the atmosphere. Vehicles are one of the many producers of carbon dioxide. Burning a gallon of gas produces approximately 24 pounds of carbon dioxide. Another way humans produce these gases is by burning coal to generate electricity. Burning wood to create a fire for cooking is another daily activity that contributes to the emission of these gases.

The other major factor contributing to the increase in greenhouse gases in the Earth’s atmosphere is deforestation. For years, humans have cut down large numbers of trees to make room for the construction of buildings and also to use wood as fuel.

Trees are very important to our ecosystems as they absorb much of the carbon dioxide from the Earth’s atmosphere. By absorbing carbon dioxide, they can carry out photosynthesis and release oxygen as a by-product. numbers, this carbon sink is greatly reduced and the amount of carbon dioxide in the atmosphere continues to increase.

Most people don’t realize how important coral is not only to marine life but to human life as well. For the communities of fish and other reef dwellers, the coral is everything to them and they all depend in some way on the structure of the coral.

What Can We Do?

There are many ways humans can help reduce the extent of coral bleaching that is occurring. Motor vehicle or kayak and canoe instead of using your boat.

Avoiding touching and breaking corals while diving or snorkeling can be of great help as just touching a coral with your bare hand can have negative effects on it.

Eliminating the use of harmful fertilizers and pesticides in your yard and garden can also be very helpful as these will eventually find their way into the sea.

Volunteering for a community reef and beach cleanup can also help keep debris out of the ocean and preventing it from entering the reefs.