The recent findings from a new study have shed light on the resilience of coral structures in the face of climate change. These structures, it seems, owe their survival to a remarkable mechanism of forming rock-hard skeletons similar to human bones.
Unraveling the Study
The research focused primarily on Stylophora pistillata, a common stony coral found in the Indo-Pacific region. The results revealed that these coral structures are composed of a biomineral containing an intricately organized mix of proteins. This mix bears a significant resemblance to the proteins in human bones. Spatial organization of these proteins is a crucial process; it is key to the formation of a coral’s rock-hard skeleton.
Moreover, the study demonstrated how corals have weathered global climate change for millions of years through a technique known as Biomineralization. This process involves the creation of hierarchically structured organic–inorganic materials by living organisms, including shells, bones, and teeth.
Understanding the Coral Life
Corals comprise genetically identical organisms called polyps, which house within their tissues microscopic algae named zooxanthellae. They share a mutually beneficial relationship, with each providing the other with crucial nourishment. Corals provide zooxanthellae with the compounds needed for photosynthesis, while the algae supply the coral with photosynthesis products necessary for the synthesis of their calcium carbonate skeletons.
Interestingly, zooxanthellae also bestow corals with unique colors, earning them the moniker “rainforests of the seas”. Two major types of corals exist: the reef-building hard, shallow-water corals and the soft corals and deepwater corals thriving in cold, dark waters.
The Ecosystem Roles of Coral
Corals act as habitats for over a million diverse marine species, including thousands of fish species. Apart from offering a vibrant ecosystem, coral reefs bring in an estimated global value of ‘$2.7 trillion per year’, including revenue from tourism and food production. They also safeguard coasts from erosion by absorbing wave energy, protecting residential areas, farmlands, and beaches. Furthermore, species living in the reefs show potential for developing treatments for numerous serious diseases.
The Threats Corals Face
Overfishing, destructive fishing techniques, unregulated recreational activities, coastal developments, and pollution all pose a significant threat to corals. Overfishing can disrupt the ecological balance of coral reefs, leading to algal overgrowth. Fishing methods such as dynamite fishing and bottom trawling can devastate entire reef ecosystems.
Coastal development, particularly in tropical regions, often compromises sensitive habitats through dredging for deep-water channels or marinas and waste material dumping. Meanwhile, pollutants—including urban and industrial waste, sewage, agrochemicals, and oil—are poisoning reefs.
Effects of Climate Change on Corals
Climate change is causing coral bleaching, a stress response that results in loss of algae and rapid whitening of the coral, primarily driven by a rise in sea surface temperatures. If this temperature increase persists, the affected coral colony can die. Furthermore, ocean acidification, which is the decrease in the pH of the Earth’s oceans due to the absorption of anthropogenic CO2, has detrimental consequences for calcifying organisms like coral reefs.
Protecting the Coral World
Several global initiatives, such as the International Coral Reef Initiative, Global Coral Reef Monitoring Network (GCRMN), Global Coral Reef Alliance (GCRA), and the Global Coral Reef R&D Accelerator Platform, are attempting to address these problems. In India, studies related to coral reefs are incorporated under Coastal Zone Studies (CZS) by the Ministry of Environment and Forests and Climate Change. The Zoological Survey of India (ZSI) is also working on a project to restore coral reefs using “biorock” technology, supported by the forest department of Gujarat. Lastly, the National Coastal Mission Program aims to protect and sustain the country’s coral reefs.