Indian Coastline & Islands — Andaman & Nicobar, Lakshadweep, Coastal Ecosystems & Blue Economy

Overview

India has a vast coastline stretching across 9 coastal states and 4 Union Territories, flanked by the Arabian Sea, the Bay of Bengal, and the Indian Ocean. The country's two major island groups — Andaman & Nicobar in the Bay of Bengal and Lakshadweep in the Arabian Sea — are strategically vital for maritime security and rich in biodiversity. India's blue economy potential, anchored by the Sagarmala programme and the Deep Ocean Mission, is a growing focus for UPSC Mains (GS-I and GS-III).

Exam Strategy: For Prelims, focus on India's coastline length, state-wise ranking, island counts, Barren Island (only active volcano), Lakshadweep's coral atolls, and coral reef locations in India. For Mains, prepare topics on blue economy, Sagarmala, CRZ regulations, and the strategic significance of Andaman & Nicobar Islands (Tri-Service Command, proximity to Strait of Malacca).

India's Coastline — Key Facts

Key Fact: The April 2025 revision from 7,516.6 km to 11,098.81 km (a 47.6% increase) is due to improved measurement technology — the 1970s figure was computed at a much smaller 1:4,500,000 scale, while the new figure uses 1:250,000 scale charts. This reflects the coastline paradox — the measured length of a coastline increases as the measurement scale becomes finer (mathematically formalised by Benoit Mandelbrot in 1967). For UPSC, both figures may be tested — note the traditional figure (7,516.6 km) in older references and the revised figure (11,098.81 km) in current affairs. Gujarat's revised coastline alone now stands at 2,340.62 km (up from ~1,600 km).

State-wise Coastline Length (Traditional)

Prelims Tip: Gujarat has the longest mainland coastline among all Indian states (~1,600 km). Among all entities including UTs, Andaman & Nicobar has the longest coastline.

Andaman & Nicobar Islands

Geography and Key Facts

Barren Island — India's Only Active Volcano

Protected Tribes

Strategic Importance

Exam Tip: The Andaman & Nicobar Command (ANC) was India's first and remains its only tri-service theatre command. It was established in 2001 at Port Blair (now Sri Vijaya Puram). Its strategic location near the Strait of Malacca — through which ~25% of global trade passes — makes these islands critical for India's maritime security and Indo-Pacific strategy.

Lakshadweep Islands

Geography and Key Facts

Coral Atolls

All Lakshadweep islands are coral atolls — ring-shaped coral reefs enclosing a shallow lagoon. They are formed by coral growth on top of submerged volcanic peaks. The islands are low-lying (highest point ~5 m above sea level), making them extremely vulnerable to sea-level rise.

PSSA Status

Lakshadweep has been designated a Particularly Sensitive Sea Area (PSSA) by the International Maritime Organisation (IMO), recognising its ecological significance and vulnerability to maritime activities.

Marine Biodiversity

Coastal Ecosystems

Mangroves

Mangroves are salt-tolerant trees and shrubs growing in the intertidal zones of tropical and subtropical coastlines. They serve as natural coastal buffers, nurseries for marine life, and carbon sinks.

Coral Reefs in India

Coral reefs are found in four major regions of India:

Key Fact: Coral reefs are NOT found in the Sundarbans — the high sediment load, turbidity, and brackish water from the Ganga-Brahmaputra delta make conditions unsuitable for coral growth. This is a frequently tested Prelims fact (UPSC 2014).

Other Coastal Ecosystems

Blue Economy

India's blue economy encompasses all economic activities related to oceans, seas, and coastal areas — including fisheries, shipping, tourism, offshore energy, and deep-sea mining.

India's Blue Economy Vision

Sagarmala Programme

Mains Relevance: The Sagarmala programme aims to reduce logistics costs by shifting cargo movement from road to coastal shipping and inland waterways. India's logistics cost (~14% of GDP) is significantly higher than global average (~8%). Port modernisation and coastal economic zones are key strategies to improve India's export competitiveness.

Coastal Regulation Zone (CRZ) — Brief Overview

Coastal Erosion

Key Fact: India loses approximately 45% of its non-rocky coastline to erosion, according to the National Centre for Coastal Research (NCCR). The most affected states include Kerala, West Bengal, Puducherry, and parts of Tamil Nadu and Odisha.

Frequently Asked Questions (Prelims Pattern)

Important Channels, Straits, and Water Bodies Around India

Prelims Tip: Remember the degree channels — Ten Degree Channel (Andaman-Nicobar), Nine Degree Channel (within Lakshadweep), Eight Degree Channel (Lakshadweep-Maldives). These are frequently tested in both Prelims and mapping questions.

Major Ports of India

India has 13 major ports (under central government, after Galathea Bay was notified as the 13th in September 2024) and over 200 minor/intermediate ports (under state governments). FY25 cargo throughput: 855 MMT total at major ports (record).

Largest port overall (incl. private): Mundra Port, Gujarat (Adani) became the first Indian port to cross 200 MMT annual cargo (200.7 MMT in FY25). Mundra is a non-major (private) port — among major ports, Paradip leads.

Key Terms for Quick Revision

Recent Developments (2024–2026)

Great Nicobar Island Development Project — Progress and Controversy

The Great Nicobar Island Development Project (GNIDP) — a ₹81,000 crore (revised 2025 estimate) holistic development initiative — continued to move forward in 2024–25. The project includes: (1) an International Container Transshipment Terminal (ICTT) at Galathea Bay, formally notified as India's 13th Major Port in September 2024; (2) a dual-use civil-military airport; (3) a 450-MW power plant; and (4) a township. The ICTT will position India to compete with Singapore (1.5 days away) as a transshipment hub near the Strait of Malacca. The project also involves significant forest diversion — about 130 sq km of tropical rainforest — raising concerns about impact on Shompen and Nicobarese indigenous communities and the leatherback sea turtle nesting sites.

UPSC angle: Great Nicobar development, India's 13th major port at Galathea Bay, strategic positioning near the Strait of Malacca, and the environment vs development trade-off are high-priority GS3 and GS2 topics.

Sagarmala 2.0 — Port Infrastructure Acceleration (2024–2025)

The Sagarmala Programme reported remarkable outcomes by 2024–25: vessel turnaround time at Indian ports dropped from 96 hours in 2014 to 49.5 hours; coastal shipping grew 118%; inland waterway cargo movement surged 700%; nine Indian ports now rank among the global top 100. The government advanced Sagarmala 2.0, with ₹40,000 crore in budgetary support targeting investments of ₹12 lakh crore over the next decade in shipbuilding, repair, recycling, and port modernisation. Out of 839 identified Sagarmala projects (total ₹5.79 lakh crore), 55 projects worth ₹3,400 crore have been completed and 68 are under implementation.

UPSC angle: Sagarmala Programme, port-led development, blue economy, and India's maritime logistics competitiveness are key GS3 infrastructure and economic geography topics.

Sources: Ministry of Ports, Shipping and Waterways (Sagarmala); PIB (pib.gov.in — Deep Ocean Mission, coastline revision); Official Lakshadweep Portal (lakshadweep.gov.in); Wikipedia (Andaman and Nicobar Islands, Lakshadweep, Barren Island); NCCR; Insights on India (coastline revision 2025); India State of Forest Report 2023; UNDP India (coral reefs).