Fig.1: Corals in Andaman Basin


The Andaman Islands are located in the Bay of Bengal, 1400 kilometres east off the coast of Chennai, one of India’s four major metropolitan cities. The islands have been vastly known for its coral reefs and sea creatures. This is the chief tourist attraction that accounts for a major part of its GDP. As years have passed since the inception of its tourist industry, persistent thermal stresses, increasing ocean acidification and an alarming rise in Sea Surface Temperature in the Andaman Basin have proven detrimental to corals, which are highly sensitive to pH and temperature. This article provides an overview of the impact of the abovementioned factors on the coral lives over the years and expands on its vulnerability, aided by empirical data.

 The beautiful article written by Aarti Prashant in ‘The Hindu’ about corals and their diversity encapsulated basic information about corals and their life structures. It simply states the importance of coral and their diversity in a subtle way. Mentioning the list of coral reefs, she pointed out the significance of the ecosystem present below the ocean. In the span of 7500km of the Indian coastline, these pink, blue, red and purple species maintain their habitation. These tiny creatures are formed from component named ‘polyps’ that majorly feeds over algae present. Corals are most abundant in the shallow waters adjoining the seashores. They are vibrant invertebrates which live in compact colonies of many identical, individual polyps. These polyps are the reason behind the vibrant colour and a unique, symbiotic relationship with unicellular algae: Zooxanthellae. Polyps are capable of regeneration if influenced by a certain amount of stress. Nowadays, increasing lethalities in environmental conditions accelerate the deterioration process, which hampers the stability of the ecosystem.

They are present in the shallow waters; hence the effects of global warming in such regions are visible. Andaman-Nicobar and Lakshadweep coastlines are major coral reserves near Indian subcontinent. Several species like sea-anemons, star fish, clownfish and lionfish reside in an area over 8000 square kilometres that includes around 500 islands. The ocean acts as the reservoir for the carbon and it was absorbing that for several million years. Presently varied pollutants from the coastline, global temperature rise and carbon emissions are showing detrimental effects over these species. Carbon oxides are majorly responsible for the ocean pH change and also impede sea-surface temperature maintenance. Since the carbon species have long lasting effect over the atmosphere they must be removed or should not be produced, but both the factors are impossible. Fossil fuels and other industries need to function in a proper manner and for the same it is unavoidable.

There are several teams all around the globe working on this issue. The complications in the environment are augmenting on a daily basis. Over the poles scientists are experiencing this at a very large scale and they are trying t solve the predicament in front of humanity. There are various professions involve operations around these oceans, Oyster farmers are one of those. Around the globe, they have seen the effect of acidification and the drastic reduction in oyster births due to the pH gradient.

Fig.2: Bleached Corals

Ocean Acidification:

The major reactions between the atmospheric CO2 and water molecules produce bicarbonates. It further leaves hydrogen ions into the water that reduces the pH and makes the water more acidic. Small clamps, shells and other species hardly grow to their full extent because they require carbonates for their survival. This factor is further hampering the food chain present over the globe. Totally 17 percent of the global population survive on fish and related food products. When the vital species of the food chain grow improperly furthered species can’t survive much longer. Hence just imagine the food scarcity and the chaos that would occur because of such issues. These issues are hidden from the world but can cause severe impact over the population.  

The eccentricity of 2004-05:

Fig.3:  Effect Earthquakes on Coral-reefs

There are several other peripheral factors involving earthquake and tsunami that causes destruction of the coral lives. For example, the North Reef Island had undergone the tsunami and ahead of that tectonic movements released the steam and hot-waves. It increased the sea-basin temperature even further. By the convection mechanism, the entire water content present had experienced the warming effect. That in turn caused increase in the ocean temperature. Those tectonic movements made the corals more vulnerable to the atmosphere and the surroundings. After in 2010, the tsunami and earthquakes disturbed the structures even further.

The effect of Ocean Acidification and increase in Sea Surface Temperatures, in theory and by experiential study, prove that Corals are deteriorating in the Andaman Islands. The relationship between SST and Coral Bleaching in Andaman is conclusive. This is a sweeping impact of Global warming on this planet. For the reduction and protection of such species which are about to become extinct many governments are taking solid steps. Indian government is sending rovers for the study and analysis of such destruction factors. So that we as a human race may help other essential species present in the ocean beds and improve the status of the environment as such.

Further Studies Required

●       Effects of other emissions such as nitrates and sulphates on coral growth

●       Quantitative impact of atmospheric and oceanic CO2 on the growth of corals in the islands.