TAG: GS 3: ECOLOGY AND ENVIRONMENT
THE CONTEXT: Coral islands, such as India’s Lakshadweep, face significant threats due to climate change, primarily caused by global warming.
EXPLANATION:
- The extraction and burning of fossil fuels, deforestation, and other anthropogenic activities contribute to rising temperatures, ocean acidification, and extreme weather events, leading to the destruction of coral reefs.
Corals and Coral Bleaching
- Coral reefs are vital ecosystems built by coral polyps, which have a symbiotic relationship with zooxanthellae algae.
- When water temperatures rise, corals expel these algae, leading to bleaching—a phenomenon where corals lose their vibrant colors and eventually die.
- Ocean acidification exacerbates bleaching by reducing calcium mineral availability for coral exoskeletons.
Types of coral reefs in India:
- Fringing reefs
- Fringing reefs evolve and develop near the continent and remain close to the coastline. These reefs are separated from the coastline by small, shallow lagoons. They are the most commonly found reefs in the world.
- Barrier reefs
- Barrier reefs are found offshore on the continental shelf. They usually run parallel to the coastline at some distance. A deep and wide lagoon is located between the coastline and the barrier reef.
- Atolls
- Atolls are formed on mid-oceanic ridges. They are shaped circularly or elliptically and are surrounded by seas on all four sides and have shallow waters in the center called a lagoon.
- All the three major reef types occur in India. The mainland coast of India has two widely separated areas containing reefs: the Gulf of Kachchh in the northwest, which has some of the most northerly reefs in the world, and Palk Bay and Gulf of Mannar in the southeast.
- In addition to these, there are patches of reef growth on the West Coast, for example, coral reefs at Malvan.
- The Andaman and Nicobar Islands have fringing reefs around many islands, and a long barrier reef (329 km) on the west coast.
- Little is known about these reefs, which may be the most diverse and pristine reefs in India. The Lakshadweep also has extensive reefs but these are also poorly explored.
Impact of Climate Change on Coral Reefs
- Global warming has resulted in widespread coral bleaching events, causing significant damage to coral reefs worldwide.
- The loss of coral reefs has severe repercussions for coastal communities, including those inhabiting coral islands like Lakshadweep, who rely on these ecosystems for livelihoods and protection from rising sea levels.
The Role of Sound in Coral Recovery
- Recent research suggests that sound may play a crucial role in coral reef recovery.
- Scientists conducted a study in the Virgin Islands, where they observed that healthy reef sounds attracted coral polyps, leading to increased settlement rates on degraded reefs.
- By using underwater speaker systems to replay healthy reef sounds, researchers saw a positive impact on coral settlement rates, indicating a potential avenue for coral restoration efforts.
Challenges and Considerations
- While the study offers promising results, it is essential to acknowledge its limitations and potential challenges.
- Scaling up this approach for large-scale coral reef restoration requires further research and testing.
- Factors such as sound volume, frequency, and other environmental parameters need to be carefully considered to ensure the success of coral settlement initiatives.
- Additionally, unforeseen complications may arise during implementation, underscoring the need for continued scientific inquiry and adaptive management strategies.
