Coral reefs in India are experiencing significant bleaching due to a combination of environmental and anthropogenic factors. Some of the key contributors to this phenomenon include:

1. Increased Sea Surface Temperatures: One of the primary drivers of coral bleaching is the rise in sea surface temperatures. Indian coastal waters have seen significant warming due to climate change. Corals are highly sensitive to temperature fluctuations, and even a slight increase can cause them to expel the symbiotic algae living in their tissues, leading to bleaching.

2. El Niño Events: These periodic climate events cause significant warming of ocean waters in various parts of the world, including the Indian Ocean. El Niño can exacerbate local temperature increases, leading to widespread bleaching events.

3. Pollution and Runoff: Coastal pollution from agricultural runoff, untreated sewage, and industrial effluents introduces harmful substances into the ocean. Nutrient-rich runoff can lead to algal blooms that block sunlight and further stress corals, while toxic pollutants can directly damage coral tissues.

4. Overfishing and Destructive Fishing Practices: The depletion of fish populations due to overfishing disrupts the ecological balance of coral reefs. Additionally, practices like blast fishing and cyanide fishing cause direct physical damage to coral structures.

5. Sedimentation from Coastal Development: Increased sedimentation from construction, deforestation, and other land-use changes reduces water quality and light penetration, essential for coral health. Sediments can smother corals, making it difficult for them to feed and grow.

6. Ocean Acidification: The absorption of excess atmospheric CO₂ by the ocean leads to lower pH levels, which affect the ability of corals to produce and maintain their calcium carbonate skeletons. This weakens the corals, making them more susceptible to bleaching and disease.

7. Invasive Species: The introduction of non-native species can disrupt local ecosystems and compete with corals for resources, adding another layer of stress to already vulnerable reefs.

8. Tourism and Recreational Activities: Unsustainable tourism practices, such as anchor dropping, trampling by divers, and coastal development for tourist infrastructure, can physically damage reefs and increase pollution levels.

Efforts to address coral bleaching in India involve a multi-faceted approach, including:

Mitigating Climate Change: Reducing global greenhouse gas emissions to limit global warming and subsequent sea temperature rise.
Improving Coastal Management: Implementing better land-use practices to reduce sedimentation and pollution runoff.
Establishing Marine Protected Areas: Creating and enforcing protected zones to safeguard coral reefs from destructive human activities.
Promoting Sustainable Fishing: Regulating fishing practices to prevent overfishing and protect reef ecosystems.
Raising Awareness: Educating local communities and tourists about the importance of coral reefs and how to minimize their impact on these ecosystems.

By addressing these factors, it is possible to reduce the incidence of coral bleaching and promote the resilience and recovery of coral reefs in India.