Islands & Coastal Features
Islands & Coastal Features of India
India has a coastline of 7,516.6 km stretching across 9 states and 4 Union Territories, and two major island groups — Andaman & Nicobar Islands in the Bay of Bengal and Lakshadweep in the Arabian Sea. Coastal geography includes harbours, lagoons, deltas, beaches, and coral reefs.
Key Dates
7,516.6 km total — 5,422.6 km mainland + 2,094 km island coastline
572 islands in Bay of Bengal; Saddle Peak (732 m) highest point
36 islands (12 atolls, 3 reefs, 5 submerged banks) in Arabian Sea; area 32 sq km
Southernmost point of India — Great Nicobar Island (6°45'N); submerged 4.25 m by 2004 tsunami
India's only active volcano — in Andaman Sea; last erupted 2017; cone rises 353 m
World's largest delta and mangrove forest — formed by Ganga-Brahmaputra system; UNESCO World Heritage Site
Longest coastline among all Indian states (1,600 km); includes Gulf of Kutch and Gulf of Khambhat
Coastal Regulation Zone rules regulate development within 500 m of high tide line; latest CRZ 2019
Indian Ocean Tsunami (Dec 26) devastated Andaman-Nicobar and Tamil Nadu coast; ~18,000 Indians killed
India's Exclusive Economic Zone: ~2.01 million sq km under UNCLOS (200 nautical miles from baseline)
Port-led development programme (2015); targets logistics cost reduction from 14% to 10% of GDP
India has 12 major ports (now 13 with Vadhavan) and ~200 minor/intermediate ports
Chain of limestone shoals (48 km) connecting Pamban Island (India) to Mannar Island (Sri Lanka)
India has ~4,992 sq km of mangrove cover (ISFR 2021); West Bengal leads (42.5% of India's total)
Andaman & Nicobar Islands
The Andaman & Nicobar Islands comprise 572 islands in the Bay of Bengal, of which only 37 are inhabited. Geologically, they are an extension of the Arakan Yoma mountain range of Myanmar — essentially the peaks of a submerged mountain chain. The islands are divided into two groups separated by the Ten Degree Channel (10°N latitude): the Andaman group in the north (North, Middle, and South Andaman collectively called "Great Andaman") and the Nicobar group in the south (19 islands including Great Nicobar, Car Nicobar, Katchal). Saddle Peak on North Andaman (732 m) is the highest point. Indira Point on Great Nicobar is the southernmost point of India. Barren Island is India's only active volcano. Narcondam Island has a dormant volcano. The islands have dense tropical evergreen forests, mangroves, and coral reefs. Indigenous tribes include the Great Andamanese, Onges, Jarawas, Sentinelese (one of the most isolated peoples in the world), and Shompens. Port Blair is the capital. The islands were severely affected by the 2004 Indian Ocean Tsunami.
Lakshadweep Islands
Lakshadweep (meaning "one hundred thousand islands") consists of 36 islands of coral origin (12 atolls, 3 reefs, 5 submerged banks, 16 uninhabited islands) in the Arabian Sea. Only 10 islands are inhabited. Total land area is merely 32 sq km, making it the smallest Union Territory by area. It is separated from the Maldives by the Eight Degree Channel (8°N) and from the Indian mainland by about 220-440 km. Kavaratti is the capital. The islands are remnants of old coral reefs (coral atolls) formed on a volcanic base. The economy depends on coconut cultivation, fishing (tuna is the primary fish), and coir processing. Minicoy is the largest island and is culturally distinct (Mahl language, close to Maldivian culture). Lakshadweep has India's only coral atoll ecosystem. The lagoons are rich in marine biodiversity. Entry to Lakshadweep requires a special permit for non-residents.
Western Coastal Features
The western coast stretches from Gujarat to Kerala along the Arabian Sea. It is generally narrow (50-65 km) due to the proximity of the Western Ghats. Key features: Gujarat Coast — includes the Rann of Kutch (a vast salt marsh, seasonal wetland; Great Rann and Little Rann; the Little Rann is home to the Indian Wild Ass/Khur); Kathiawar/Saurashtra Peninsula; Gulf of Khambhat and Gulf of Kutch; Coral reefs in the Gulf of Kutch. Konkan Coast — Maharashtra and Goa; rocky, with natural harbours like Mumbai (Mumbai harbour is formed between Mumbai Island and Salsette Island); sea cliffs, laterite plateaus. Karnataka Coast (Kanara) — bounded by Western Ghats; minor ports like Mangalore, Karwar; river estuaries. Malabar Coast — Kerala; famous for backwaters (Kayals) — interconnected network of lagoons, lakes, and canals; Vembanad Lake (longest lake in India) is the centrepiece; natural harbours at Kochi (Cochin); spice gardens on the slopes behind the coast.
Eastern Coastal Features
The eastern coast stretches from Tamil Nadu to West Bengal along the Bay of Bengal. It is broader (100-130 km) and has extensive deltas. Key features: Coromandel Coast (Tamil Nadu) — sandy beaches, few natural harbours; Chennai (Madras) is an artificial harbour; Mahabalipuram/Mammallapuram shore temple; Marina Beach (one of the longest urban beaches). Andhra Coast — includes Pulicat Lake (second largest brackish water lagoon in India, on Tamil Nadu-Andhra Pradesh border), Krishna-Godavari Delta (rich in natural gas); Visakhapatnam — only natural harbour on the east coast. Odisha Coast — Chilika Lake (largest brackish water lagoon in India, Ramsar site, home to Irrawaddy dolphins); Mahanadi Delta; Bhitarkanika mangroves (mass nesting of Olive Ridley turtles). West Bengal Coast — Sundarbans Delta (world's largest delta and mangrove forest); Hooghly River estuary; Kolkata (Calcutta) — upstream port city; Digha beach. Major deltas on the east coast: Mahanadi Delta, Godavari Delta, Krishna Delta, Kaveri Delta (granary of South India).
Coral Reefs of India
India has four major coral reef regions: (1) Gulf of Kutch — fringing reefs on the southern coast of the Gulf; about 42 islands with reef formations; Pirotan Island is a Marine National Park (India's first, 1982). (2) Gulf of Mannar — between India and Sri Lanka; includes the 21-island Gulf of Mannar Marine National Park and Biosphere Reserve; one of the richest marine biodiversity zones in India; over 3,600 species of flora and fauna. (3) Andaman & Nicobar Islands — fringing reefs around most islands; some of the best-preserved reef systems in India; Mahatma Gandhi Marine National Park near Wandoor (Port Blair) showcases underwater coral. (4) Lakshadweep — atoll reefs; the only true atolls in India; lagoons enclosed by ring-shaped reefs. Types of coral reefs: Fringing reefs (attached to shore, most common in India), Barrier reefs (separated from coast by lagoon, not prominent in India), and Atolls (ring-shaped, only in Lakshadweep). Threats to coral: rising sea temperatures cause coral bleaching (loss of symbiotic zooxanthellae algae); ocean acidification reduces calcium carbonate availability; sedimentation from rivers; pollution; overfishing; tourism damage. India signed the International Coral Reef Initiative (ICRI). Major bleaching events: 1998, 2010, 2016 affected Indian reefs significantly.
Coastal Regulation Zone (CRZ)
The CRZ Notification (first in 1991, latest CRZ 2019) regulates activities in coastal areas under the Environment Protection Act 1986. The CRZ 2019 classifies coastal zones into: CRZ-I — ecologically sensitive areas (mangroves, coral reefs, sand dunes, nesting grounds of sea turtles); no construction permitted; includes inter-tidal zone. CRZ-II — developed urban areas already substantially built up; buildings permitted on the landward side of existing road/structures. CRZ-III — rural and undeveloped areas; "No Development Zone" (NDZ) of 200 m from high tide line (reduced from 500 m in CRZ 1991 for densely populated rural areas to 50 m). CRZ-IV — water area from low tide line to 12 nautical miles seaward; fishing and allied activities permitted; no untreated sewage discharge. Key changes in CRZ 2019: NDZ reduced for densely populated rural areas, floor space index (FSI) norms relaxed in CRZ-II, temporary tourism facilities allowed in "No Development Zones" on a case-by-case basis, and Coastal Zone Management Plans (CZMPs) to be prepared by all coastal states. Critics argue CRZ 2019 dilutes environmental protection by reducing NDZ and allowing more construction in sensitive areas.
Mangroves of India
India has about 4,992 sq km of mangrove cover (India State of Forest Report 2021), constituting about 3.3% of the world's mangroves. India ranks 5th globally in mangrove cover after Indonesia, Brazil, Nigeria, and Australia. State-wise: West Bengal leads with 2,114 sq km (42.5% of India's total, mainly Sundarbans), followed by Gujarat (1,177 sq km, mainly Gulf of Kutch and Gulf of Khambhat), and Andaman & Nicobar Islands (616 sq km). The Sundarbans is the world's largest single contiguous mangrove forest, shared between India and Bangladesh; a UNESCO World Heritage Site (1987); home to the Royal Bengal Tiger (unique mangrove tigers that swim between islands); faces threats from rising sea levels, cyclones, salinity intrusion, and the Farakka Barrage reducing freshwater flow. Bhitarkanika (Odisha) is the second-largest mangrove forest in India; mass nesting site of Olive Ridley sea turtles at Gahirmatha beach nearby; home to the saltwater crocodile. Pichavaram (Tamil Nadu) is one of the largest mangrove forests in southern India. Ecological functions: mangroves act as natural buffers against cyclones and tsunamis (the 2004 tsunami demonstrated this — areas behind dense mangroves suffered significantly less damage); nursery grounds for fish and prawns; carbon sinks; prevent coastal erosion. India has a National Mangrove Committee and several mangrove restoration projects under the Integrated Coastal Zone Management Programme.
Indian Ocean Islands — Strategic Significance
India's island territories have immense strategic importance for maritime security and Blue Economy: (1) Andaman & Nicobar Command — India's only tri-services theatre command (Army, Navy, Air Force), established in 2001 at Port Blair; commands a strategic position at the entrance to the Strait of Malacca (one of the busiest shipping lanes in the world, carrying ~$5 trillion in trade annually); India can monitor naval movements in the Bay of Bengal and eastern Indian Ocean. (2) INS Baaz — India's southernmost air base at Campbell Bay, Great Nicobar; close to the Strait of Malacca. (3) INS Dweeprakshak — Lakshadweep naval base at Kavaratti; helps secure the western sea approaches and the Nine Degree Channel. (4) Great Nicobar Development Plan — proposed mega-project including a transhipment port, international airport, power plant, and township; controversial due to environmental concerns (Great Nicobar has pristine rainforests, leatherback turtle nesting beaches, and indigenous Shompen/Nicobarese tribes). (5) India's "Neighbourhood First" Maritime Policy — India has developed port and infrastructure projects in neighbouring island nations: Assumption Island (Seychelles), Agalega (Mauritius), Sabang Port (Indonesia) — to counter China's "String of Pearls" strategy. (6) Blue Economy — India's maritime economy contributes about 4% of GDP; fisheries alone employ 16 million people; deep-sea mining potential in India's EEZ for polymetallic nodules (India has a claim in the Central Indian Ocean Basin under the International Seabed Authority).
Major Ports and Maritime Infrastructure
India has 13 major ports (governed by the Major Port Authorities Act 2021) and about 200 minor/intermediate ports (under state governments). Major ports: Western coast — Deendayal Port (Kandla, Gujarat — handles bulk cargo, one of the busiest), Mumbai Port (oldest major port, established 1873), JNPT (Nhava Sheva, Navi Mumbai — largest container port, handles 50%+ of container traffic), Mormugao (Goa — iron ore exports), New Mangalore (Karnataka — handles POL and iron ore), Cochin Port (Kerala — natural harbour, handles containerized and liquid cargo). Eastern coast — Tuticorin/V.O. Chidambaranar Port (Tamil Nadu), Chennai Port (2nd oldest, established 1881 — artificial harbour), Ennore/Kamarajar Port (Tamil Nadu — India's first corporatized port, 2001), Visakhapatnam Port (AP — only natural harbour on east coast, largest by cargo volume), Paradip Port (Odisha), Kolkata/Haldia (WB — riverine port on Hooghly, Syama Prasad Mookerjee Port), Dhamra (Odisha — private). Vadhavan Port (Maharashtra) — the proposed 13th major port, will be India's largest container port. The Sagarmala Programme (2015) targets port-led development: port modernization, coastal economic zones, port connectivity enhancement, and skills development; aims to reduce logistics cost from 14% to 10% of GDP.
Coastal Hazards and Vulnerability
India's 7,500+ km coastline is exposed to multiple natural hazards: (1) Cyclones — Bay of Bengal generates 5-6 cyclones annually; east coast (Odisha, AP, TN, WB) is far more cyclone-prone than the west coast; Odisha Super Cyclone 1999 (10,000+ deaths), Fani 2019, Amphan 2020, Hudhud 2014 were devastating; west coast cyclones are increasing (Tauktae 2021, Biparjoy 2023). (2) Tsunami — the 2004 Indian Ocean Tsunami killed about 18,000 people in India (mainly Tamil Nadu, Andaman & Nicobar, AP, Kerala, Puducherry); led to establishment of Indian Tsunami Early Warning Centre (ITEWC) at INCOIS, Hyderabad in 2007; deep-ocean tsunami detection buoys deployed. (3) Coastal Erosion — about 33% of India's coastline is affected by erosion; Kerala (67% eroding), Puducherry, and West Bengal are most affected; causes include sea-level rise, sand mining, construction of sea walls/groynes disrupting sediment transport, and removal of mangroves. (4) Sea Level Rise — India's coast is rising at 1.7 mm/year (global average 3.1 mm/year); threatens low-lying areas like Sundarbans, Lakshadweep, and Mumbai; climate change projections suggest acceleration; Lakshadweep (max elevation 5 m) is existentially threatened. (5) Saline Water Intrusion — overexploitation of groundwater in coastal areas allows seawater to infiltrate freshwater aquifers; severe in Gujarat, Chennai, and Sundarbans.
Coastal Geomorphology — Landforms
Key coastal landforms found along India's coast: (1) Beaches — accumulations of sand/pebbles along the shore; Marina Beach (Chennai, 13 km — one of the longest urban beaches in the world), Juhu Beach (Mumbai), Puri Beach (Odisha), Goa beaches (Calangute, Baga, etc.); beaches form where wave energy deposits sediment. (2) Spits and Bars — elongated deposits of sand connected to the mainland at one end; examples include the sandbar enclosing Chilika Lake and the Willingdon Island (man-made from dredged material in Cochin harbour). (3) Lagoons — shallow coastal water bodies separated from the sea by bars/spits; Chilika (Odisha), Pulicat (AP-TN), Vembanad (Kerala); lagoons are important ecosystems but face siltation. (4) Deltas — fan-shaped deposits of alluvium at river mouths; India has some of the world's largest deltas: Sundarbans (Ganga-Brahmaputra, ~80,000 sq km), Godavari Delta, Krishna Delta, Mahanadi Delta, Kaveri Delta. (5) Estuaries — funnel-shaped river mouths where fresh and salt water mix; Hooghly Estuary (WB), Zuari/Mandovi Estuaries (Goa), Narmada and Tapi Estuaries (Gujarat); estuaries are biologically productive. (6) Sea Cliffs and Stacks — formed by wave erosion on rocky coasts; seen along the Konkan Coast (Maharashtra-Goa). (7) Rann — a unique landform; the Great Rann of Kutch is a vast seasonally inundated salt marsh (about 7,500 sq km) — neither land nor sea for part of the year.
Fisheries and Coastal Livelihoods
India is the 3rd largest fish producer in the world (after China and Indonesia) and the 2nd largest aquaculture producer. Marine fisheries contribute about 36% and inland fisheries 64% of total fish production. About 16 million people are employed in fisheries, predominantly in coastal areas. India's Exclusive Economic Zone (EEZ) of ~2.01 million sq km has rich fishing grounds. Andhra Pradesh leads in fish production (mainly aquaculture), followed by West Bengal and Gujarat. Kerala and Tamil Nadu are leaders in marine catch. Key fish varieties: oil sardine, mackerel, Bombay duck, tuna, shrimp/prawn. The fisheries sector faces challenges: overfishing in nearshore areas, declining catches per unit effort, pollution affecting breeding grounds, climate change altering fish migration patterns, and post-harvest losses (~30%). Blue Revolution (Neel Kranti Mission, 2016) aims to achieve sustainable fisheries production — targets 15 million tonnes by 2020 and 22 million tonnes by 2025; promotes deep-sea fishing, aquaculture, and seaweed cultivation. Pradhan Mantri Matsya Sampada Yojana (PMMSY, 2020) — Rs 20,050 crore scheme to boost fisheries infrastructure and production. India exports about $7.7 billion worth of marine products (2022-23); shrimp is the dominant export item. Fishing harbours at Kochi, Visakhapatnam, Mangalore, Veraval, and Paradip are among the largest.
Olive Ridley Sea Turtles and Coastal Biodiversity
India's coast hosts remarkable biodiversity: (1) Olive Ridley Sea Turtles — mass nesting (arribada) at Gahirmatha beach, Odisha (the world's largest rookery), and at the mouths of the Rushikulya and Devi rivers; females arrive in huge numbers (hundreds of thousands) between January-March; Gahirmatha Marine Sanctuary protects them; threats include trawler fishing (incidental catch), artificial lighting on beaches, and predation. Operation Olivia (Indian Coast Guard) patrols nesting beaches during the season. (2) Leatherback Sea Turtles — nest on the beaches of Great Nicobar Island; the largest species of turtle; threatened by the proposed Great Nicobar development project. (3) Marine Mammals — Irrawaddy dolphins (Chilika Lake, Sundarbans), Indo-Pacific humpback dolphins (Gulf of Kutch, west coast), dugong (sea cow) — found in Gulf of Mannar, Palk Bay, and Andaman (India's dugong population is about 200-250, critically endangered). (4) Saltwater Crocodile — Bhitarkanika (Odisha) has the largest population in India; also found in Sundarbans and Andaman. (5) Coral reef biodiversity — over 200 species of hard coral found in Indian waters; Gulf of Mannar has 117 species of coral and 450 species of fish. India has 4 Marine National Parks: Gulf of Kutch MNP (Gujarat), Gulf of Mannar MNP (Tamil Nadu), Mahatma Gandhi MNP (Andaman), and Rani Jhansi MNP (Andaman).
Rann of Kutch — A Unique Landscape
The Rann of Kutch is a unique seasonal wetland/salt marsh in Gujarat, divided into the Great Rann (about 7,500 sq km) and the Little Rann (about 5,000 sq km). During the monsoon (July-September), the Rann is flooded by seawater from the Arabian Sea and freshwater from rivers like the Luni (which disappears into the Rann); during the dry season (October-June), it becomes a vast expanse of white salt crust. The Great Rann is one of the largest salt deserts in the world. Ecologically, the Little Rann is home to the Indian Wild Ass (Ghudkhur/Khur) — the last population of this species survives here in the Wild Ass Sanctuary; estimated population ~6,000. The Rann Utsav (Festival of Rann) held at Dhordo celebrates the unique landscape and culture of Kutch. Flamingo City in the Great Rann is a major breeding ground for greater flamingos. The India-Pakistan international border runs through the Great Rann; the Sir Creek dispute (India-Pakistan) over the maritime boundary in the Rann remains unresolved. Dhola-vira — an important Indus Valley Civilization site — is located on Khadir Island in the Great Rann (UNESCO World Heritage Site, 2021). The Rann is seismically active — the 2001 Gujarat Earthquake (Bhuj earthquake, 7.7 magnitude) devastated Kutch.
Climate Change and Coastal India
Climate change poses existential threats to India's coastal regions: (1) Sea Level Rise — IPCC AR6 projects 0.3-1.0 m rise by 2100 under different scenarios; India's coast rising at 1.7 mm/year; Lakshadweep (max elevation 5 m) and parts of Sundarbans may be submerged; Mumbai, Chennai, Kolkata face increased flooding risk. (2) Increased Cyclone Intensity — while total cyclone frequency may not increase significantly, the proportion of severe and very severe cyclones is rising; Arabian Sea cyclones (traditionally rare) are increasing (Ockhi 2017, Tauktae 2021, Biparjoy 2023); warming Indian Ocean fuels more intense storms. (3) Coral Bleaching — rising sea temperatures cause mass bleaching events; 2016 event killed 70-80% of coral in parts of Gulf of Mannar and Lakshadweep; ocean acidification (CO2 absorption reduces pH) weakens coral skeletons. (4) Sundarbans Submersion — several islands (Lohachara, Ghoramara, New Moore/South Talpatti) have already been lost to rising seas; Mousuni Island is being evacuated; an estimated 7,500 people in Sundarbans have become climate refugees. (5) National Action Plan on Climate Change (NAPCC, 2008) includes the National Mission for Sustaining the Himalayan Ecosystem and the National Water Mission but lacks a dedicated coastal mission; the Coastal Zone Management Authorities are responsible for integrating climate adaptation. (6) Mangrove restoration is a key adaptation strategy — mangroves sequester 3-5 times more carbon per unit area than tropical forests and protect against storm surges.
Maritime Zones Under International Law
Under the United Nations Convention on the Law of the Sea (UNCLOS, 1982), maritime zones are: (1) Internal Waters — waters inside the baseline (rivers, harbours); full sovereignty. (2) Territorial Sea — up to 12 nautical miles (nm) from the baseline; full sovereignty but must allow "innocent passage" to foreign ships. (3) Contiguous Zone — 12-24 nm; state can enforce customs, fiscal, immigration, and sanitation laws. (4) Exclusive Economic Zone (EEZ) — up to 200 nm; sovereign rights over natural resources (fisheries, seabed minerals, energy production); other states have freedom of navigation and overflight; India's EEZ is ~2.01 million sq km. (5) Continental Shelf — natural prolongation of the land territory to the outer edge of the continental margin, or 200 nm (whichever is greater, up to 350 nm); India filed a submission to the UN Commission on Limits of Continental Shelf (CLCS) for extended shelf beyond 200 nm. (6) High Seas — beyond EEZ; freedom of navigation, fishing, scientific research. India enacted the Maritime Zones Act 1976 and the Territorial Waters, Continental Shelf, EEZ and Other Maritime Zones Act to implement UNCLOS provisions. India's maritime claims: 12 nm territorial sea, 24 nm contiguous zone, 200 nm EEZ; baseline drawn using the "straight baseline" method for some coasts.
Relevant Exams
Islands and coastal geography is frequently tested. UPSC asks about Ten Degree Channel, Eight Degree Channel, Palk Strait, coral reef types, and CRZ regulations. SSC/RRB exams test southernmost point of India, largest/smallest islands, state with longest coastline, and lagoon/lake identification. Maritime zones (EEZ, Territorial Sea), Sagarmala, and port-related questions appear in current affairs. Coastal hazards, mangroves, and climate change impacts on coasts are growing in UPSC relevance.