Coral reefs, often dubbed the “medicine cabinets of the 21st century” due to their role in medicine development, are among the planet’s most diverse ecosystems. These ecosystems offer numerous ecological, economic, and medicinal benefits and are crucial to maintaining a healthy marine environment.
Depletion of Corals (Coral Bleaching):
Change in Temperature:
- Above-average seawater temperatures can cause stress to coral reefs.
- Example in the Indian context: The Indian Ocean experienced significant coral bleaching events in recent years due to rising sea temperatures associated with climate change.
Stress Induced in Corals:
- Stressors include epizootics (diseases) and excessive sedimentation.
- Example: The 2016 mass bleaching event in the Great Barrier Reef was exacerbated by disease outbreaks and sediment runoff.
Xenobiotics (External Substances):
- Substances like copper, herbicides, and oil can harm coral reefs.
- Case in point: The 2017 oil spill off the coast of Chennai, India, posed a significant threat to nearby coral ecosystems.
Runoff and Pollution:
- Agricultural runoff and pollution from human activities can degrade water quality and harm corals.
- Indian example: The degradation of coral reefs in the Gulf of Mannar due to pollution and overfishing.
Extreme Low Tides:
- Sudden exposure of reef flat corals to the atmosphere during events like extreme low tides can induce bleaching.
- India’s Lakshadweep Islands have witnessed coral bleaching events during El Niño events.
- Sediment runoff from construction and deforestation can smother corals.
- For instance, the Andaman and Nicobar Islands have experienced coral damage due to sedimentation from human activities.
Importance of Corals:
- Corals act as natural barriers, protecting coastlines from wave action and tropical storms.
- India’s Lakshadweep and Andaman Islands benefit from this protection.
Habitats for Marine Organisms:
- Corals provide essential habitats and shelter for numerous marine species, including fishes, starfish, and sea anemones.
- The Gulf of Kutch in India is renowned for its rich coral-associated biodiversity.
- Corals are a source of nitrogen and other nutrients vital for marine food chains.
- This nutrient cycling supports fisheries in the Indian Ocean.
- Corals assist in carbon and nitrogen fixation, nutrient recycling, and maintaining ecological balance.
- These services are critical for sustaining marine ecosystems in the Indian Ocean.
- Coral reefs boost revenue and employment through tourism and recreation.
- Tourism in places like the Andaman Islands contributes significantly to the local economy.
Cultural and Industrial Uses:
- Corals are used in jewelry, and coral blocks are employed in buildings and road construction.
- Additionally, coral lime is a valuable component in the cement industry.
The coral ecosystem is a vital component of marine biodiversity, offering multifaceted benefits. To safeguard these invaluable ecosystems, urgent measures are required, including conservation efforts, sustainable resource management, and global climate action, to mitigate the factors causing coral depletion. Protecting India’s coral reefs is not just an ecological necessity but also an economic and cultural imperative.