Corals!..... about climate change leading to dystopia

 CLIMATE CHANGE KILLING THE 'RAINFORESTS OF THE SEA' PAVES THE WAY FOR A DYSTOPIAN WORLD

The term "coral reefs" automatically induces an image of a beautiful and colourful plant-like structure growing within the vastness of the sea. But did you know that these structures otherwise referred to as the 'rainforests of the sea' are a complex ecosystem supporting life? As unbelievable as it might sound, providing aesthetic beauty is not their sole purpose of existence.

 Coral reefs are made up of colonies of stony coral polyps surrounded by a hard skeletal structure, so contrary to what's popularly believed they are animals and not plants belonging to the phylum Cnidaria. Coral reefs are some of the planet's most diverse and productive ecosystems. Coral diversity simply refers to the variety of species that exist in coral reefs. The world's coral reefs are home to more than 25 per cent of all marine life forms on the planet, including over 4000 species of fish and thousands of species of invertebrates, algae, and other organisms. Corals themselves are known to exist as more than 8000 different species. They provide a habitat for a variety of fish and other marine organisms. They are nurseries for baby fish and provide food for large fish and other organisms. Reefs also provide an important source of income for local communities through fishing, tourism, and other activities.

These spectacular creations are found in tropical and subtropical waters all around the world, covering over 6,00,000 square miles of the ocean. The largest concentration of coral reefs is found in the Indo-Pacific region, particularly in the coral triangle which covers the waters of Indonesia, Malaysia, the Philippines, Papua New Guinea, and the Solomon Islands. This region has been awarded the title of being the most "coral-rich area" for it contains over 600 species of hard corals alone, representing more than 75 per cent of the world's known coral species. Along with the coral triangle, the Caribbean is also an important centre of coral diversity, housing more than 500 known coral species. Other important coral reef areas include the Red sea, the Indian Ocean, the Central Pacific, and the great barrier reef in Australia.

 

[fringing reef]

   

[the Great Barrier Reef]

 Unfortunately, coral reefs are among the most vulnerable ecosystems to the effects of climate change. The impact of climate change on coral reefs is already being felt and is expected to worsen in the near future. Let me give you a live example, the great barrier coral reef of Australia that was mentioned a moment ago, yes, the one that's so large it's visible from space. Today the coral reef is only half of what it used to be in the 1980s.

 Over the years climate change has caused an increase in ocean temperatures leading to increased chances of coral bleaching. In simple terms, coral bleaching occurs when the coral polyp expels the algae living inside its tissue, causing the corals to become white. Since the symbiotic algae were responsible for providing food to the coral polyp, their chances of mortality increased due to lack of food. Even though coral bleaching is reversible, it has caused the death of more than half of the World's coral reefs.

In addition to coral bleaching, climate change has increased the ocean's carbon dioxide content absorption, leading to ocean acidification. When the ocean water turns acidic, it causes the coral's calcium carbonate skeleton to dissolve. Finally, climate change is also initiating an increase in extreme weather events such as hurricanes which cause physical damage to coral reefs, destroying the reef as well as other organisms living in the reefs

 

 

For a moment imagine a dystopian world where all the coral reefs have been destroyed. How different do you think the world would be?

For starters, there will be no stable coastal communities due to flooding from rising sea levels and increasingly powerful storms, since there would be no coral reefs to act as a buffer against storms and waves. Coral reefs also stabilise the sea bed, without them the sea bed would become more susceptible to erosion. Moving on, coral reefs support tourism and fisheries, which provide economic opportunities in many tropical countries hence, without them many communities would suffer economically, and the marine species living in the corals would likely go extinct. Reefs are known to play an important role in absorbing carbon dioxide. Without them, the carbon dioxide content in the atmosphere would increase tremendously leading to global warming. Lastly, corals have an inbuilt filtration system that improves water quality, therefore not having coral reefs would impact the water quality of the oceans negatively.

 Even though coral reefs are constantly under the threat of extinction, they have an inherent defence mechanism labelled regeneration. Just as the name implies, it is the process by which damaged or diseased coral colonies are naturally regenerated or replaced by healthy ones. It is a crucial part of the ecosystem and plays an important role in the health of coral reefs. Sounds great! The only problem is that it's an incredibly slow process. The main reason for this is that corals are extremely picky and require characteristic environmental conditions to grow including warm and clear water, adequate sunlight, and the presence of healthy coral colonies to carry out the replacement. Moreover, settling the coral larvae on the seafloor before it starts building colonies naturally takes time. Adding to all of this is the easy disruption of coral colonies due to natural events such as storms and bleaching events.

 Let me help you visualise this with some data. The Global Coral Reef Monitoring Network (GCRMN) shows that a total of 19.4 per cent area of coral reefs has declined between 1996 and 2006 and this trend has continued in the years since. In addition to this, a study conducted by Smithsonian Institution in the Caribbean found the average rate of coral regeneration to be 1 to 6 cm per year. If you do the maths, it's pretty clear, at that rate it would take anywhere between 5 to 30 years for a single coral colony to reach the size of 1 meter in diameter. That means it would take decades for coral reefs to recover from the impact of human activities such as pollution and overfishing.

 Assuming that you are convinced of the importance coral reefs hold in running our world, you might be and technically you should be curious about what can be done to protect them. If you think about it, the antagonist in the life of coral reefs is increased water temperature, which is caused due to increased greenhouse gas emissions. If that can be reduced the threat to coral reefs is automatically reduced simultaneously diminishing many more environmental problems. See how it's a total win-win situation.

Along with causing visible damage to coral reefs, climate change is also responsible for coral destruction behind the scenes. A very eminent example of this is the rising rate of pollution that is triggered by climate change which in turn worsens coral damage. Pollutants such as sewage, agricultural runoff, and oil can increase the stress on coral reefs, making them more exposed to bleaching and other forms of damage like coral diseases. These diseases have had a devastating effect on coral populations worldwide. For instance, consider the coral disease "white plague" that has caused considerable mortality in Caribbean coral reefs, particularly in the Florida Keys. It is estimated that white plague has killed over 90 per cent of the staghorn coral Acropora cervicornis leading to a dramatic shift in the composition of coral reef communities.

[white plague disease]

 Even after a significant reduction in greenhouse gas emissions, If the reefs are still damaged, they can be rejuvenated thanks to advances in scientific technologies, through methods like coral transplantation, artificial reef structures, etc. These methods can also help boost the resilience of reefs and protect them from the effects of climate change.

One of the most recent endeavours to protect coral reefs has been the use of "coral nurseries". These are small, protected areas of the ocean where coral fragments are grown in a controlled environment that is free from threats such as pollution and overfishing. Once the corals have grown and reproduced, they are transplanted back onto the degraded reefs helping in the restoration and regeneration of the damaged reefs.

[ coral nurseries]

 Obviously, not everybody can perform these intricate operations, but the general public can raise awareness about the consequences of climate change on coral reefs. 'Education is the stepping stone to changes' thus, educating people about the significance of coral reefs can help reduce activities that damage them, such as anchoring boats and collecting corals.

 As has been demonstrated in the above write-up, climate change is instigating a devastating impact on coral reefs around the world. And as a protective measure, it is critical to take steps to reduce greenhouse gas emissions and mitigate the effects of climate change. By taking action to safeguard coral reefs, we can ensure that these indispensable ecosystems remain healthy and fruitful for future generations.

~ Bipasha Pan