Day 41 – Q. 3. Explain the ecological significance of coral reefs. How do phenomena like ocean acidification and coral bleaching threaten marine biodiversity and coastal economies? (150 words, 10 marks)

Q. 3. Explain the ecological significance of coral reefs. How do phenomena like ocean acidification and coral bleaching threaten marine biodiversity and coastal economies? (150 words, 10 marks)

Introduction 

Coral reefs, often called the “rainforests of the sea,” cover less than 1% of the ocean floor  yet support nearly 25% of all marine life. Their ecological significance and vulnerability have  drawn global conservation focus. 

Body 

Ecological Significance of Coral Reefs 

2. Biodiversity Hotspots: Coral reefs provide  critical habitat to over 4,000 species of  fish and countless invertebrates, playing a  vital role in sustaining global marine  biodiversity. Example: Great Barrier Reef hosts more  than 1,500 fish species. 
3. Coastal Protection: Reefs act as natural  barriers against wave action, storms, and  erosion, safeguarding shorelines and  coastal populations. Example: Coral systems around Lakshadweep reduce wave energy by over 70%.
4. Breeding and Nursery Grounds: Many marine organisms use coral reefs as breeding,  spawning, and nursery grounds, ensuring continuity of fish populations. Example: Groupers, snappers, and lobsters spawn in reef ecosystems. 
5. Livelihood and Food Security: Coral reefs support fisheries, tourism, and associated  livelihoods, particularly in tropical coastal regions. Example: Over 500 million people globally depend on reefs for food and income.

Threats from Ocean Acidification and Coral Bleaching 

1. Ocean Acidification: Increased CO₂ absorption reduces carbonate ion concentration,  hampering coral calcification and weakening reef structures. Example: Indian Ocean reefs are experiencing reduced growth rates due to acidification.
2. Coral Bleaching Events: Rising sea temperatures lead corals to expel symbiotic algae  (zooxanthellae), turning them white and leading to mortality. Example: The 2016 bleaching event affected nearly 90% of corals in the Great Barrier  Reef. 
3. Ecosystem Collapse: Loss of coral reefs destabilizes food chains, leading to decline in fish  stocks and impacting predator-prey dynamics. Example: Maldives reported loss of reef fish post-bleaching events. 
4. Economic Losses: Decline in reef tourism, fisheries, and protection services result in  direct economic setbacks for coastal economies. Example: Coral degradation could cost Southeast Asia over $38 billion annually by 2050.

Government and Global Initiatives 

1. MISHTI (Mangrove Initiative for Shoreline Habitats and Tangible Incomes): Though  focused on mangroves, it indirectly supports coral ecosystems through integrated coastal  zone management. 
2. Use of Biorock Technology: Adopted in the Gulf of Mannar and Andaman Islands to  restore damaged reefs using low-voltage electrical currents to enhance coral growth. 3. ENVIS Reef Monitoring: Under the Environment Ministry, regular monitoring of coral  health is conducted in states like Gujarat and Tamil Nadu. 
3. UNDP-GEF Project: Promotes coral reef conservation through protected area  management in marine zones such as Gulf of Mannar and Malvan. 
   

Conclusion

Coral reefs are crucial to biodiversity, economy, and coastal security. Combating their  degradation through direct interventions and global cooperation is vital to achieving SDG 13 (Climate Action) and SDG 14 (Life Below Water).