“Warming is projected to exceed the ability of reefs to survive within one to three decades for the majority of the World Heritage sites containing coral reefs, This severe bleaching frequency will rapidly kill most corals present and prevent successful reproduction necessary for the recovery of corals.” reports UNESCO in its first global scientific assessment. Scientists across the globe believe that the world’s coral reefs are in jeopardy unless there is a reduction in the carbon emission levels to slow down ocean warming.
Coral reefs, often referred to as ‘tropical rainforests of the sea’ can be considered to be one of the most productive and fragile ecosystems providing a habitat for millions of underwater species. They are also known to guard the coastlines against erosions and act as a barrier to sea-level rise.
It is disheartening to know that the coral reefs which survived for over thousands of years of natural changes may not be able to sustain due to the devastation caused by mankind. Under physiologically stressful conditions -like low tides, pollution and elevation of sea surface temperature due to global warming, corals tend to lose their symbiotic algae which further leads to its whitening, a condition known as ‘bleaching’. Massive coral bleaching incidents have been on a rise worldwide. Scientists observed the outbreak of a parasitic sponge- Terpios hoshinota post the bleaching incident in the Gulf of Munnar in 2016. They also found that the dead corals provided a breeding ground for these invasive species which further flourish and kill the live corals.
Overfishing using destructive methods like cyanides and dynamites is responsible for the breakage of the fragile coral reefs. This poison often gets into the nooks and crannies of the coral polyps and ultimately leads to coral death.
Unsustainable tourism and unlimited construction projects have led to the destruction of the coastal ecosystem. The intrusion of wastewater or freshwater into the oceans is making the coral reefs devoid of the salty environment and hence leading to its further degradation. Excessive nutrients like phosphorus and nitrogen promote the rapid growth of algae which further suffocates the corals and compels fishes to survive in low nutrient environments.
While the world’s coral reefs, from the Great Barrier Reef off Australia to the rich coral reefs of India’s Andaman and Nicobar islands are turning into graveyards due to El Nino effects and ocean acidification, the impact of notorious human activity has led to the formation of plastic reefs as a result of plastic waste dumped in the oceans. According to a UN-based survey, an astonishing 11.1 billion plastic items were found entangled in the corals in reefs of Pacific regions of Asia. And it has been estimated that there would be a 40% rise in just seven more years. There are also pieces of evidence of the ingestion of plastic debris and microplastics by the marine wildlife which is causing havoc in the marine ecosystem.
Loss of corals might be very lethal for some islands like Lakshadweep where the existence and carrying capacity of landmass depends on the atoll reef formation. The decline in the corals may lead to the disruption of the structural affinity of corals and hence lead to their submergence.
Now since the loss in the biodiversity and global threat to the reefs are omnipresent, the local protection from overfishing or farm runoffs is not sufficient. The entire world should act faster to reduce greenhouse gas emissions, conserve water to reduce the production of wastewater, and more importantly by being responsible tourists. We need to respect the oceans as if our life is dependent on it. Because it does, and now is the time we act.
Author: Himaja Darbha
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