Coastal & Marine Ecosystems — Blue Economy & Ocean Conservation

India's Coastline — Key Facts

India possesses the world's 6th longest coastline, stretching 7,516.6 km in total (mainland: 5,422 km; island territories: 2,094 km). This coastline passes through 9 coastal states and 4 union territories.

State-wise coastline length:

India's coastline supports over 250 million people living in coastal areas, with fishing, shipping, and tourism as primary livelihoods.

Coral Reefs — Structure and Types

Coral reefs are among the most biodiverse ecosystems on Earth, covering less than 1% of the ocean floor but supporting approximately 25% of all marine species. They are built by reef-building (hermatypic) corals — colonial organisms in the phylum Cnidaria.

Types of Coral Reefs

Coral Bleaching Mechanism

Corals host symbiotic algae called zooxanthellae within their tissues. These algae provide up to 90% of the coral's energy through photosynthesis and give corals their colour.

When seawater temperatures rise even 1–2°C above the seasonal maximum for 4+ weeks:

1. Corals experience thermal stress and expel zooxanthellae
2. Corals turn white ("bleach") — they are still alive but stressed
3. Without zooxanthellae, corals cannot obtain adequate nutrition
4. If stress persists, corals die and the reef structure degrades

Other bleaching triggers: freshwater influx, sedimentation, ocean acidification, and disease.

India's Coral Reef Zones

The estimated total coral reef area in India is approximately 2,375 km², distributed across four main zones:

The Gulf of Mannar and Palk Bay are the only major coral formations along India's mainland coast.

4th Global Mass Bleaching Event (2023–2025)

On April 15, 2024, NOAA (National Oceanic and Atmospheric Administration) in partnership with the International Coral Reef Initiative (ICRI) confirmed the 4th global coral bleaching event — the largest on record.

Key facts:

• From January 2023 to September 2025, bleaching-level heat stress affected ~84.4% of the world's coral reef area
• Mass bleaching confirmed in at least 62 countries and territories worldwide
• NOAA had to extend the Bleaching Alert scale to Alert Level 5 to indicate near-complete mortality
• Australia's Great Barrier Reef underwent its 5th extensive bleaching event since 2016; Australian Institute of Marine Science reported over a third of live hard coral killed in northern GBR regions — the largest annual drop in nearly 40 years of records
• Cause: Record-breaking global temperatures in 2023–24 (2024 confirmed Earth's hottest year on record) combined with El Niño conditions

Previous global bleaching events: 1998, 2010, 2015–2016, 2023–2025.

Mangroves — India's Blue Carbon Forests

Mangroves are salt-tolerant, intertidal forests found along tropical and subtropical coastlines. They are critical to coastal ecology and climate resilience.

India's Mangrove Cover — ISFR 2023

As per the 18th India State of Forest Report (ISFR) 2023 released by the Forest Survey of India:

• Total mangrove cover: 4,991.68 sq km (0.15% of India's geographical area)
• Net change since ISFR 2021: slight decrease of 7.43 sq km
• But long-term trend is positive: net increase of 363.68 sq km (7.86%) since 2013 and 509.68 sq km (11.4%) since 2001

State-wise mangrove cover (major states):

Why Mangroves Matter

Sundarbans (West Bengal/Bangladesh border): UNESCO World Heritage Site; largest contiguous mangrove forest in the world (~10,000 sq km total, with ~4,200 sq km in India); habitat of the Royal Bengal Tiger.

Seagrasses — The Overlooked Ecosystem

Seagrasses are submerged flowering plants (angiosperms) that form underwater meadows in shallow coastal waters. They differ from seaweeds (algae).

• Seagrass meadows are critical carbon sinks (blue carbon) — can sequester carbon 35x faster than tropical rainforests
• Primary food source for dugongs (sea cows) and green sea turtles in Indian waters
• India's seagrass hotspots: Gulf of Mannar, Palk Bay, Lakshadweep, Andaman Islands
• The dugong (Dugong dugon) is classified as Vulnerable (IUCN) and is the State Animal of the Andaman & Nicobar Islands; protected under Schedule I of Wildlife Protection Act, 1972
• Seagrass is threatened by coastal development, boat propeller scarring, and water quality degradation

Coastal Regulation Zone (CRZ) Notification 2019

The CRZ Notification 2019 (replacing CRZ Notification 2011) regulates activities in India's coastal areas based on ecological sensitivity.

CRZ Classification

Key Changes: CRZ 2019 vs CRZ 2011

• Reduced No Development Zone (NDZ): For densely populated rural areas (CRZ-IIIA), NDZ reduced from 200m to 50m — to allow more construction
• Mangrove buffer: Protected buffer zone of 50 metres around mangroves (was not uniform in 2011)
• Blue Flag beaches: Provisions to facilitate Blue Flag certification for clean beaches
• Eco-tourism: Temporary tourism structures permitted in CRZ-III areas under regulation
• Island territories: Special provisions for Andaman & Nicobar and Lakshadweep (CRZ-IV) recognising unique ecology

Blue Economy — India's Maritime Potential

The Blue Economy refers to the sustainable use of ocean resources for economic growth, livelihoods, and ocean ecosystem health. India's ocean area (~2.02 million sq km EEZ) holds enormous potential.

NITI Aayog Blue Economy Policy (2021)

The Draft Blue Economy Policy 2021 (prepared by NITI Aayog) estimated India's blue economy contribution at $186 billion (approximately 4% of GDP) with potential to grow significantly. Key sectors identified:

Sagarmala Programme

Launched in 2015 under Ministry of Ports, the Sagarmala Programme focuses on port-led development: port modernisation, port connectivity, port-linked industrialisation, and coastal community development.

Deep Ocean Mission (DOM)

India's Deep Ocean Mission was launched in June 2021 under the Ministry of Earth Sciences (MoES) with a budget outlay of ₹4,077 crore over 5 years.

Key Objectives

India is one of 7 countries in the world with a crewed deep-sea submersible programme.

Marine Protected Areas (MPAs) — India

India's total MPA coverage is relatively low compared to global standards. The 30x30 target (protecting 30% of land and ocean by 2030) under the Kunming-Montreal Global Biodiversity Framework (2022) requires significant expansion.

Plastic Pollution in Oceans

• Great Pacific Garbage Patch: A gyre of ocean plastic between Hawaii and California, estimated at 1.6 million sq km — three times the size of France
• 8 million tonnes of plastic enter oceans annually
• Microplastics: Plastic particles < 5mm; found in deep sea sediments, Arctic ice, marine organisms, and human blood
• MARPOL Annex V: International Convention for the Prevention of Pollution from Ships; prohibits disposal of garbage (including plastics) from ships at sea
• India banned single-use plastics (items < 75 micron) from July 1, 2022

International Legal Frameworks

The BBNJ Agreement is the 3rd implementing agreement under UNCLOS. Morocco became the 60th country to ratify in September 2025, triggering entry into force in January 2026.

Marine Fisheries

• India is the 3rd largest fish producer globally (after China and Indonesia) with annual production of ~14.73 million tonnes (2022-23)
• Marine fisheries contribute ~1% to GDP and provide livelihoods to ~28 million people
• Key fishing states: Gujarat, Kerala, Tamil Nadu, Andhra Pradesh, Maharashtra
• Overfishing and trawling threaten fish stocks; India follows a 61-day fishing ban (June–July) on west coast and 45-day ban on east coast for resource replenishment
• Blue Flag Certification: An international eco-label for beaches meeting standards on water quality, environmental education, safety, and environmental management; India has Blue Flag certified multiple beaches including Shivrajpur (Gujarat), Kappad (Kerala), Rushikonda (Andhra Pradesh)
• PM Matsya Sampada Yojana (PMMSY): ₹20,050 crore scheme (2020–25) for fisheries sector development

Previous Year Questions (PYQs)

Prelims

1. With reference to India's coastal ecosystem, which of the following statements is/are correct? (UPSC CSE Prelims 2019)

   • Mangroves act as nurseries for commercially important fish species
   • Coral reefs in India are found in four regions: Gulf of Kutch, Gulf of Mannar, Lakshadweep and Andaman & Nicobar
   • CRZ Notification 2011 categorises coastal areas into four zones

2. The term "Blue Carbon" refers to: (UPSC CSE Prelims 2021)

   • Carbon sequestered by ocean ecosystems including mangroves, seagrasses, and saltmarshes

3. Consider the following: 1. Dugong 2. Green turtle 3. Irrawaddy dolphin. Which of these are associated with the Lakshadweep and Gulf of Mannar coastal ecosystems? (Pattern question)

4. With reference to UNCLOS, which one of the following is correct regarding India's Exclusive Economic Zone (EEZ)?

   • It extends up to 200 nautical miles from the baseline

Mains

1. The Indian Ocean region is acquiring strategic significance for India. Examine the importance of a robust Blue Economy policy for India's maritime development and national security. (GS3, 2023 pattern — 15 marks)

2. Coral bleaching has emerged as a major environmental threat. Discuss the mechanism of coral bleaching and the significance of India's coral reef systems. What steps has India taken for their protection? (GS3 — 15 marks)

3. Comment on the significance of India's Deep Ocean Mission for the Blue Economy. How does it align with India's resource security interests? (GS3 — 10 marks)

4. The BBNJ Agreement (High Seas Treaty) is considered a landmark in international ocean governance. Discuss its key provisions and India's strategic interest in the high seas. (GS2/GS3 — 15 marks)

Exam Strategy

For Prelims:

• Memorise CRZ zone classifications (I to IV) — type and activities allowed
• Know coral reef types (fringing, barrier, atoll) with Indian examples
• Mangrove cover figure from ISFR 2023: 4,991.68 sq km
• BBNJ Treaty: adopted June 2023, entered into force January 2026
• Matsya 6000: depth capability = 6,000 metres; under Ministry of Earth Sciences
• India's coastline: 7,516.6 km; 9 states + 4 UTs

For Mains:

• Structure answers on Blue Economy using: fisheries → energy → minerals → tourism → shipping framework
• Coral bleaching: use the zooxanthellae mechanism for precision in technical explanations
• CRZ questions: contrast 2019 vs 2011 changes; emphasise NDZ reduction controversy
• Deep Ocean Mission: link to critical minerals strategy, UNCLOS rights in CIOB, and India's maritime power aspirations
• Mangroves: always mention blue carbon as a climate mitigation tool, not just biodiversity angle

Key Linkages:

• Deep Ocean Mission ↔ Critical Minerals Strategy (polymetallic nodules: Ni, Co, Mn, Cu)
• BBNJ Treaty ↔ India's High Seas interests ↔ UNCLOS framework
• CRZ 2019 ↔ Coastal communities ↔ Livelihood vs conservation tension
• Coral bleaching ↔ Climate change ↔ Ocean warming (1.5°C Paris threshold)