Coral Bleaching: Gulf of Mannar, Coral Health, Global Example | UPSC Notes

The Gulf of Mannar, a marine biodiversity hotspot between India and Sri Lanka, faces severe coral bleaching due to climate change. Artificial reef restoration using concrete modules enhances coral survival, fish density, ecosystem resilience, and community livelihoods.

The Gulf of Mannar & Coral Bleaching is essential for UPSC General Studies Paper III (Environment & Ecology) under biodiversity, conservation efforts, climate change impacts, and sustainable livelihoods, linking environmental challenges with community resilience and ecological restoration measures. Join the UPSC coaching today and boost your preparation.

Last 10 Years UPSC Question Papers 

Gulf of Mannar

The Gulf of Mannar, a shallow sea in the Indian Ocean between India and Sri Lanka, was home to 21 islands, reefs made by stony corals, mangroves and seaweed. On India's West coast, it hosts that country's first Marine Biosphere Reserve that shelters and supports a variety of marine life and coastal human endeavors.

Geographic Setting

• Lies in the Laccadive Sea of the Indian Ocean, between the southeast coast of India and northwest Sri Lanka.
• Encompasses 21 islands.
• Bounded by Rameswaram, Adam's Bridge (Ram Setu), and Mannar Island (Sri Lanka).
• Tambraparni (India) and Malvathu Oya (Sri Lanka) are major rivers draining into the gulf.
• Known for Tuticorin port, pearl banks, and the sacred chank (a gastropod mollusk).

Download the Daily Current Affairs for UPSC Here!
 

Gulf of Mannar Marine National Park

• • Established in 1982 under the Wildlife (Protection) Act, 1972.
  • Area: 162.89 km².
  • Ecosystems: coral reefs, mangroves, seagrass beds, estuaries, mudflats, sandy shores, marshes, rocky coasts.

• Biodiversity:

• • 117 coral species
  • 450+ fish species
  • Threatened fauna: sea cow (Dugong dugon), whale sharks, and sea turtles

Gulf of Mannar Biosphere Reserve

• Established in 1989, recognized by UNESCO in 2001.
• Area: 10,500 km², including 21 islands and surrounding coastal regions.
• Encompasses the Marine National Park.
• First Marine Biosphere Reserve in South and South-East Asia.
• Serves as a vital hub of marine biodiversity and conservation.

Read The Article Marine Protected Areas (MPAs) Here!

What is Coral Bleaching?

Coral bleaching is a phenomenon in which corals lose their vibrant colors due to the expulsion of symbiotic algae called zooxanthellae. These algae provide nutrients to the corals through photosynthesis and give them their characteristic hues. When stressed by various factors, corals expel the algae, leading to their bleached appearance.

Coral Reefs 

Coral reefs are diverse underwater ecosystems formed from the skeletons of coral polyps. Here are some key things to know about coral reefs:

• Coral reefs comprise the hard limestone exoskeletons of coral polyps, tiny marine invertebrates. Over time, the skeletons build up into massive underwater structures.
• Coral polyps contain photosynthetic algae that provide them with energy and nutrients. This symbiotic relationship allows the coral to grow and build reef structures.
• Coral reefs support extremely high biodiversity. They provide habitat for around a quarter of all marine species, including fish, mollusks, sponges, worms, crustaceans and more.

Read The Article Wildlife Protection Act,1972 Here!

Features of Bleached Corals

Bleached corals are pale or white, contrary to healthy coral reefs that are brightly colored. This removes the energy source of the coral and exposes the coral to disease, growth retardation, and, where the stress continues, death.

Causes of Coral Bleaching

• Elevated Water Temperatures: Increased water temperatures, primarily due to climate change, can induce stress on corals, leading to bleaching.
• Pollution: Pollution from human activities, such as runoff from agriculture and coastal development, can degrade water quality and cause stress to corals.
• Ocean Acidification: Increasing carbon dioxide levels in the atmosphere can result in ocean acidification, negatively impacting coral health.
• Ultraviolet Radiation: Excessive exposure to ultraviolet (UV) radiation due to the thinning ozone layer can stress corals and trigger bleaching.

Coral Bleaching in India

Coral bleaching in India is significant in the Andaman and Nicobar Islands, Lakshadweep, Gulf of Mannar, and Gulfs of Mannar and Kachchh, and it is attributable to increases in sea temperature along with pollution and climate change, with potentially catastrophic effects to the marine life and livelihoods that depend on the coast.

Major Coral Regions in India

• Gulf of Mannar (Tamil Nadu)

• Lakshadweep Islands

• Andaman & Nicobar Islands

• Gulf of Kachchh (Gujarat)

Causes of Bleaching in India

• Climate change: warming oceans, marine heatwaves.
• Pollution & sedimentation from coastal industries and rivers.
• Unsustainable fishing & tourism.
• Cyclones & ocean acidification.
   

Impact

• Decline in marine biodiversity (fish, turtles, Dugongs).
• Threat to fisheries, livelihoods, and coastal protection.
• Loss of carbon sink & ecosystem services.

Conservation & Restoration

• Marine Protected Areas (e.g., Gulf of Mannar Marine National Park).
• Coral transplantation & artificial reef modules.
• Community-based eco-tourism & awareness.
• Climate action: emission cuts, sustainable coastal management.

Global Examples of Coral Bleaching

Coral bleaching has been recorded in most parts of the globe. Among the best-known reefs are the Great Barrier Reef off Australia, the Florida Keys off the United States, the Maldives in the Indian Ocean and the Andaman Sea on the south coast of the mainland of Southeast Asia.

Read The Article Environment Protection Act(EPA) Here!

Why is Coral Health Important?

Coral reefs are a crucial ecosystem that sustains a rich variety of marine life. They give homes, breeding habitats, and food to many species. Coral reefs help prevent coastal erosion and provide an economic asset in forms of tourism and fisheries, and coral reefs help regulate the global climate as carbon sinks.

Global Initiatives for Coral Reefs Protection

Here are some major global initiatives working towards coral reef protection:

• International Coral Reef Initiative (ICRI) - A partnership of over 120 countries, territories and organizations working to conserve and manage coral reefs worldwide. ICRI aims to facilitate international cooperation, commitments and actions to address threats to coral reefs.
• Coral Reef Alliance (CORAL) - An international NGO focused on empowering local communities to conserve their coral reefs through education, training and sustainable livelihoods. CORAL works in over 15 countries across the globe.
• Reef Renewal - A joint program by The Nature Conservancy and International Coral Reef Action Network aimed at restoring key coral reef functions through innovative techniques. It works across the Caribbean and Indian Ocean.
• Global Coral Reef Monitoring Network (GCRMN) - A network established under ICRI to monitor the health of coral reefs globally and provide data to guide management actions. It involves scientists and managers from over 80 countries.
• Rescue a Reef - A global network of reef restoration projects working to propagate and outplant corals, educate communities and fund scientific research. It operates across 40 countries that contain coral reefs.
• Healthy Reefs for Healthy People - The International Union for Conservation of Nature initiative focused on holistically managing coastal ecosystems with coral reefs in ways that benefit both nature and human wellbeing.
•  United Nations Environment Programme (UNEP) - UNEP addresses threats to coral reefs through programs focused on addressing climate change, pollution reduction, sustainable fisheries and ecosystem-based management.

Read The Article Coastal Regulation Zone Notification (CRZ) Here!

Way Forward

We must address the root causes, mitigate climate change, reduce pollution, and promote sustainable practices to combat coral bleaching. Raising awareness about the importance of coral reefs and their conservation is vital. Individuals can contribute by practicing responsible tourism, reducing their carbon footprint, and supporting initiatives that protect coral reefs.

Testbook provides a set of comprehensive notes for different competitive exams. Testbook is always at the top of the list because of its best quality assured products like live tests, mocks, Content pages, GK and current affairs videos, and much more. To study more topics for UPSC, download the Testbook App now.