Dr. David Vaughan, a scientist and manager at the Elizabeth Moore International Center for Coral Reef Research & Restoration, has defined coral reef as “a ridge or mound of limestone, the upper surface of which is near the surface of the sea and which is formed of calcium carbonate by the actions of organisms, chiefly corals.”
Due to the combined effect of global warming, local pressures, and climate change, coral reefs are the world’s most threatened ecosystems. Coral reefs have been suffering from mass coral bleaching due to greenhouse gas emissions and other anthropogenic activities leading to raised global temperatures. The Lakshadweep coral reefs have shrunk by 40%.
Due to the rich biodiversity that coral reefs support, they are called the rainforests of the oceans. Because they have huge importance in our ecosystem, we must conserve them.
Importance of Coral Reefs
Coral reefs form the world’s richest ecosystems and support the highest biodiversity. They are a host to a plethora of marine fish species. Additionally, they are an important component of the marine food chain.
Coral reefs live in a symbiotic relationship with the algae. The algae are able to trap the sun’s energy and synthesize their own food. Therefore, corals are primary producers in the food chain. They provide profit by sustaining the fishing and tourism industries.
Coral reefs protect the coasts from storms, high waves, tides, and floods. Corals protect the seashores from cyclones and storms by reducing the impact of high waves before they hit the shore.
They are also the key indicators of global ecosystem health, as they can only grow in a specific range of temperatures. Therefore, the loss of coral reefs will have huge economic and health consequences for the world.
Climate change refers to the change in the environmental conditions on Earth. These changes have adverse effects on ecology and the ecosystem. Anthropogenic activities like industrialization, pollution, deforestation, urbanization, etc. are the reasons behind the changing climate leading to the rising temperatures of the earth. The glaciers are melting, the water level in the oceans and sea is rising, carbon dioxide in the air is increasing, and biodiversity is being affected negatively due to climate change.
Coral reefs live in a close symbiotic association with algae called zooxanthellae. The algal partner is photosynthetic and can provide food to the coral; in return, the coral provides protection to the algae. The algae also provide color to the corals. Therefore, algae and the coral reefs are equally important to each other’s survival.
Corals are sensitive to sea temperature. When the corals experience a rise in temperature, they become stressed and expel out the algae. This process is known as coral bleaching, which can cause the death of the coral reefs.
Australia’s Great Barrier Reef has lost 30% of its corals due to heatwaves causing coral bleaching.
Thus, by warming the oceans and inducing coral bleaching, climate change is threatening this integral marine ecosystem.
The rising sea temperatures due to global warming will lead to the loss of coral reefs. The shorelines will consequently become more prone to erosion and storms. Loss of coral reefs also poses a threat to communities dependent on seafood. Therefore, it will have an adverse effect on health and nutrition. Added on to that, coral reefs are a source of revenue for many countries in the form of tourism; those countries will have to bear huge economic loses.
There is a need to pay attention to climate change’s effect on coral reefs. Cutting carbon emissions leading to global warming and decarbonizing shipping is mandatory. Protection of mangroves and salt marshes is another necessary action. The fish should be sustainably harvested rather than intensively fished. Moreover, research should be done to select heat-resistant coral reefs that can sustain rising temperatures because of global warming.