Coral Reefs, Mangroves and Seagrasses: Interactive Map and Complete Study Guide

One Connected Seascape

Coral reefs, mangroves and seagrasses are not three separate topics but a single land-to-ocean system. Mangroves trap river sediment so the water reaching the seagrass meadows is clear enough for light; offshore, coral reefs break the ocean swell and create the calm lagoon that mangroves and seagrass need. Fish and prawns move between all three across their lives — damage one and the others suffer.

CoralCoral Reefs

A coral reef is a limestone structure built over centuries by tiny animals called coral polyps, which secrete cups of calcium carbonate. Their secret is a partnership: inside their tissue live microscopic algae called zooxanthellae that photosynthesise and hand over most of the sugar they make. This is why reefs need clear, sunlit, shallow, warm water (23–29°C) in the tropics — and why heat causes bleaching, when the coral expels its algae, turns white and can starve.

Global distribution and latitudinal limits

Most shallow, reef-building corals occur in tropical and subtropical seas between about 35°N and 35°S, with reef diversity falling sharply beyond roughly 30° north and south. Their greatest concentration lies in the Indo-Pacific, especially the Coral Triangle around Indonesia, the Philippines and Papua New Guinea. The Pacific contains substantially more reef-coral species than the Atlantic, while the Caribbean is the principal Atlantic reef province.

Latitude alone does not decide reef location. Reefs are scarce along many tropical western coasts of continents because cold eastern-boundary currents and coastal upwelling lower sea temperatures and bring nutrient-rich water that favours plankton and algae rather than clear-water coral growth. The Peru or Humboldt Current and Benguela Current help explain the limited reef development along western South America and south-western Africa. Reefs are also poorly developed near major river mouths, where freshwater, mud and silt reduce salinity and block sunlight.

Physical conditions required for reef building

• Temperature: most tropical reef builders grow best at about 23–29°C and generally cannot sustain reef growth below about 18°C. Each reef population is adapted to its own local seasonal temperature range.
• Latitude and solar energy: strong year-round insolation in low latitudes supports the photosynthesis of zooxanthellae.
• Light and depth: most vigorous reef growth occurs in the sunlit upper water column, commonly within about 30 m, although light-dependent mesophotic corals can occur much deeper in exceptionally clear water.
• Salinity: reef-building corals normally require fully marine water, commonly around 32–42 parts per thousand, and are stressed by large or rapid salinity changes.
• Water clarity: clear, low-turbidity water is essential. Suspended sediment shades corals, settles on polyps and forces them to spend energy cleaning their surfaces.
• Low to moderate nutrients: reefs flourish in relatively nutrient-poor, oligotrophic seas because their coral–algal partnership recycles nutrients efficiently. Excess nitrogen and phosphorus encourage phytoplankton and fleshy algae that compete with corals.
• Stable substrate: coral larvae need a hard surface on which to settle. Loose mud, mobile sand and rapidly shifting deltaic sediment discourage reef construction.
• Water movement: waves and currents bring oxygen and plankton, remove waste and prevent sediment accumulation, but extreme wave energy and cyclones can break reef frameworks.

Important distinction: these controls apply mainly to shallow tropical reefs. Many coral species live in cold, deep and dark water, but deep-sea corals do not depend on zooxanthellae and usually do not form the familiar tropical reef ecosystems shown on this map.

How a reef grows

Each polyp deposits a calcium-carbonate skeleton. Colonies grow upward and outward, while coralline algae cement loose material and waves break old skeletons into reef sediment. A living reef therefore has a carbonate budget: construction by corals and algae must exceed erosion by waves, boring organisms, grazing fish and chemical dissolution. Sea-level change, tectonic movement, subsidence, sediment supply and wave exposure control the final landform.

Reef types (Darwin’s subsidence theory)

• Fringing reef — grows directly against the shore (most common).
• Barrier reef — separated from land by a lagoon (e.g. the Great Barrier Reef).
• Atoll — a ring of reef around a lagoon where a volcanic island has since sunk beneath the sea (e.g. Maldives, Lakshadweep).
• Patch reef — a small, isolated reef rising from a lagoon or continental shelf.
• Platform or bank reef — develops on a broad shallow shelf, often away from a major island or continental coast.

Darwin explained the classic sequence as a volcanic island slowly subsiding while coral continues to grow upward: fringing reef → barrier reef → atoll. Modern geography adds the effects of glacial sea-level changes, pre-existing shelf topography, tectonics and differential erosion.

Reef zonation

• Lagoon or back reef: sheltered water behind the reef; often contains patch reefs, sand, seagrass and mangroves.
• Reef flat: broad, shallow platform exposed to strong sunlight, temperature change and sometimes low tide.
• Reef crest: highest-energy zone where waves break; dominated by robust corals and coralline algae.
• Fore reef or reef slope: seaward face descending into deeper water, commonly with high coral diversity where light remains sufficient.

Coral bleaching: process, causes and consequences

Bleaching is a stress response, not immediate death. During prolonged heat stress, especially when combined with intense sunlight, photosynthesis inside the zooxanthellae becomes disrupted and produces damaging reactive molecules. The coral loses or expels much of the algae and their pigments, revealing the white limestone skeleton through transparent tissue. Without its main food source, the coral has less energy for growth, reproduction, defence and skeletal repair.

• Marine heatwaves: the leading cause of mass bleaching. Risk depends on how far temperature rises above the local seasonal maximum and how long the anomaly persists. NOAA expresses accumulated thermal stress through Degree Heating Weeks.
• El Niño and circulation anomalies: can weaken normal cooling, reduce cloud cover and create unusually warm, calm surface water over major reef regions.
• High solar and ultraviolet exposure: intensifies heat damage, especially in shallow water during clear, calm weather.
• Extreme low tides: may expose shallow corals to air, overheating and desiccation.
• Freshwater and salinity shock: intense rainfall, floods or altered evaporation can rapidly dilute or concentrate seawater.
• Sediment, nutrients and pollution: runoff, sewage, fertiliser, pesticides, oil and industrial contaminants reduce water quality, promote algal growth and increase disease susceptibility.
• Cold-water shock: unusually low temperatures can also cause bleaching, although global mass events are primarily driven by excessive heat.
• Disease and biological stress: pathogens and outbreaks such as crown-of-thorns starfish can compound thermal damage and slow recovery.

If normal conditions return quickly, surviving corals may regain algae and recover. Repeated or prolonged bleaching can cause starvation, disease, reduced reproduction and mortality. Recovery is slow where herbivorous fish are overharvested, algae dominate, water quality is poor or larval connections with healthy reefs have been broken.

Bleaching and ocean acidification are different processes. Bleaching mainly reflects physiological stress, especially heat. Ocean acidification occurs as seawater absorbs carbon dioxide, lowering pH and reducing carbonate availability; this makes skeleton building more difficult and weakens the reef framework. Both pressures operate together under climate change.

Ecological and geographical importance

• Provide three-dimensional habitat, feeding grounds, nurseries and spawning sites for exceptionally high marine biodiversity.
• Dissipate wave energy and reduce coastal erosion, storm damage and lagoon turbulence.
• Support fisheries, tourism, recreation, medicines and the livelihoods of tropical island and coastal communities.
• Create reef islands, cays, lagoons and carbonate sediments that become major coastal landforms.

Major human pressures and management

Besides climate change, reefs are damaged by destructive fishing, overfishing of herbivores, mining of coral and sand, poorly managed tourism, anchors, dredging, ports, coastal construction, sediment runoff, sewage, plastics, invasive species and disease. Effective management combines greenhouse-gas reduction with marine protected areas, sustainable fisheries, watershed management, sewage treatment, mooring controls, coral nurseries, assisted recovery and long-term heat-stress monitoring.

India: exam-ready distribution

• Lakshadweep: India’s classic atoll reefs, built on the Chagos–Lakshadweep ridge in the Arabian Sea.
• Andaman & Nicobar Islands: extensive fringing and barrier-type reefs in a tectonically active island arc.
• Gulf of Mannar and Palk Bay: fringing and patch reefs associated with islands, seagrass beds and the shallow shelf between India and Sri Lanka.
• Gulf of Kachchh: unusual high-latitude, turbid and strongly tidal reefs adapted to large temperature and salinity variations.

Reefs cover under 1% of the ocean floor but support around 25% of all marine species — hence “rainforests of the sea.” The defining threat today is marine heat: the fourth global bleaching event (2023–2025) hit about 84% of the world’s reef area, the largest on record. India’s reefs lie in the Gulf of Mannar, Gulf of Kachchh, Lakshadweep and Andaman & Nicobar Islands.

MangroveMangroves

Mangroves are salt-tolerant trees (halophytes) that grow in the intertidal zone of tropical coasts — the only forests rooted in salt water. To survive salt, mud and tide they evolved stilt and prop roots, upward-growing breathing roots (pneumatophores), salt-excreting leaves, and vivipary (seeds that sprout on the parent tree).

Distribution and biogeography

Mangroves are concentrated along tropical and subtropical shores, broadly within about 30°N and 30°S, although warm currents and mild winters allow some species to extend farther poleward. Their outer limits are controlled less by average annual temperature than by extreme winter cold and frost. As freezing events become less frequent, mangroves are expanding into some subtropical salt-marsh zones.

They occur mainly on sheltered, low-energy coasts: river deltas, estuaries, tidal creeks, lagoons, bays, mudflats and the landward side of barrier islands. They are uncommon on steep rocky coasts, exposed surf beaches and shores with no intertidal sediment platform. The world’s mangroves form two broad biogeographic realms: the species-rich Indo-West Pacific, centred on South and Southeast Asia, and the less diverse Atlantic–East Pacific, covering tropical America and western Africa.

Physical controls on mangrove development

• Warm climate: frost-free tropical or subtropical conditions are the main climatic requirement.
• Tidal inundation: regular flooding connects forests to estuaries and the sea, transports nutrients and propagules, and creates salinity and oxygen gradients.
• Shelter from waves: protected coastlines permit fine sediment to settle and seedlings to establish.
• Soft sediment: mud, silt, sand or organic peat provides anchorage, though species differ in substrate preference.
• Low-oxygen soils: waterlogging excludes air from the soil, favouring plants with aerial roots and internal oxygen-transport tissues.
• Salinity: mangroves tolerate fresh, brackish and saline conditions, but most grow fastest where some freshwater reduces salt stress and supplies sediment and nutrients.
• Sediment balance and elevation: the forest floor must build vertically fast enough to remain within the tidal frame. Too little sediment, erosion or rapid relative sea-level rise can drown a forest.
• Freshwater and river discharge: rainfall and rivers regulate salinity, sediment and nutrient supply; dams and embankments can disrupt these flows.

Major mangrove landform settings

• Riverine mangroves: tall, productive forests along tidal rivers and distributaries receiving freshwater, nutrients and sediment.
• Fringe mangroves: narrow belts along open bays, islands and estuary margins directly exposed to tides.
• Basin mangroves: inland depressions behind the coastal fringe, flooded less frequently and often more saline.
• Overwash mangroves: low islands or peninsulas flooded across much of their surface during high tides.
• Scrub or dwarf mangroves: stunted forests on nutrient-poor, hypersaline or poorly flushed flats; small size reflects environmental stress rather than a different tree species.

Adaptations to salt, waterlogging and unstable sediment

• Prop and stilt roots: brace trees against tides and waves while trapping sediment.
• Pneumatophores and lenticels: project above anoxic mud and allow gas exchange during low tide.
• Salt exclusion: some roots filter much of the salt before water enters the plant.
• Salt excretion and storage: some species remove salt through leaf glands or store it in old leaves and bark that are later shed.
• Thick or succulent leaves: reduce water loss under physiological drought, because salty water is difficult for roots to absorb.
• Vivipary and buoyant propagules: seedlings begin developing on the parent tree, then float with tides until they lodge in suitable mud.

Zonation and ecosystem functioning

Mangrove forests commonly show bands from sea to land because species differ in tolerance of flooding, salinity, wave exposure and soil chemistry. The seaward edge may be dominated by species with strong prop roots, while landward zones experience less frequent flooding but sometimes greater hypersalinity. This zonation is not universal: local topography, freshwater flow, tidal range and disturbance can produce mixed or reversed patterns.

Roots slow tidal currents and trap sediment, while leaf litter feeds a detritus-based food web. Tidal creeks connect the forest with mudflats, seagrass beds and reefs, carrying organic matter, fish, crabs and prawns between habitats. Mangroves therefore function as both a terrestrial forest and a marine nursery.

Ecosystem services

• Coastal protection: roots and trunks reduce current and wave energy, stabilise sediment and can lower storm-surge damage. Protection depends on forest width, density, health, water depth and storm intensity; mangroves reduce risk but do not make exposed coasts disaster-proof.
• Fisheries: submerged roots provide refuge and nursery habitat for fish, prawns, molluscs and crabs.
• Water quality: forests trap sediment and absorb nutrients before they reach seagrass meadows and coral reefs.
• Blue carbon: large carbon stores accumulate in woody biomass, roots and especially deep waterlogged soils.
• Livelihoods: mangroves support honey, fuelwood, timber, medicines, fisheries, tourism and cultural practices when harvesting is sustainable.

Threats, coastal squeeze and restoration

Major causes of loss include conversion to shrimp ponds and agriculture, ports and urban growth, roads and embankments, timber cutting, oil spills, plastics, altered river discharge, dredging, erosion and poorly planned tourism. Climate change adds sea-level rise, stronger heat and salinity stress, changing rainfall and more intense storms. Where seawalls or development block landward migration, rising seas create coastal squeeze: the forest is trapped between deepening water and fixed infrastructure.

Successful restoration begins by repairing tidal hydrology, freshwater flow, sediment supply and ground elevation. Planting seedlings without correcting these physical controls often fails. Natural regeneration is preferable where propagules and suitable tidal conditions remain; active planting is most useful after site conditions have been restored and locally appropriate species selected.

India: distribution and geographical examples

• Sundarbans: the Ganga–Brahmaputra–Meghna delta; the world’s largest continuous mangrove forest, shaped by tides, distributaries, sediment and cyclones.
• Bhitarkanika and Mahanadi delta: Odisha’s tidal creeks, mudflats and estuarine mangroves.
• Godavari and Krishna deltas: important east-coast mangroves influenced by river discharge, aquaculture and delta modification.
• Pichavaram and Muthupet: Tamil Nadu lagoon and estuary systems with intricate tidal channels.
• Gulf of Kachchh: arid-coast mangroves adapted to high salinity, large tides and limited freshwater.
• Andaman & Nicobar Islands: species-rich island mangroves associated with creeks, bays and coral–seagrass systems.

The latest Global Mangrove Watch maps about 147,256 km² of mangroves worldwide; Indonesia alone holds ~21%, and the Sundarbans (India–Bangladesh) is the largest single mangrove forest and the only one roamed by tigers. Mangroves are carbon vaults (storing ~394 t C per hectare) and natural sea walls that blunt cyclones and storm surge. India’s cover is 4,991.68 km² (ISFR 2023), led by West Bengal’s Sundarbans and Gujarat; the MISHTI scheme (2023–28) aims to restore ~540 km². Their biggest threat is clearing for aquaculture, rice and oil palm.

SeagrassSeagrasses

Seagrasses are not seaweed. Seaweeds are algae; seagrasses are true flowering plants (angiosperms) that returned to the sea, with roots, veins, flowers and pollen. About 72 species form underwater meadows in clear, shallow, sheltered water, spreading by underground stems (rhizomes).

Global distribution

Seagrasses are more widely distributed by latitude than tropical coral reefs and mangroves. They occur from equatorial seas to high temperate and sub-Arctic coasts, in 159 countries across six continents, but not Antarctica. Tropical diversity is highest in the Indo-Pacific, where many species may grow together. Temperate coasts are often dominated by eelgrasses such as Zostera, while the Mediterranean is characterised by the long-lived endemic Posidonia oceanica.

Physical controls on seagrass meadows

• Light: the primary control. Because the whole plant is submerged, enough sunlight must reach the seabed for photosynthesis. The lower depth limit becomes shallower where water is turbid and deeper where water is exceptionally clear.
• Depth: most meadows occupy intertidal and shallow subtidal shelves, lagoons and bays. Some species extend beyond 40–50 m in very clear water, while muddy estuaries may restrict growth to only a few metres.
• Water clarity: suspended sediment, phytoplankton and algae growing on leaves reduce light and are major causes of decline.
• Substrate: roots and rhizomes require reasonably stable sand, mud, rubble or mixed sediment. Constantly shifting sand and severe erosion prevent establishment.
• Wave and current energy: many meadows favour sheltered or moderately exposed settings. Strong waves uproot plants, while complete stagnation can worsen heat, oxygen and sulphide stress.
• Salinity: tolerances differ among species. Some grow in fully marine water, others in estuaries and brackish lagoons; rapid freshwater or hypersaline shocks can cause die-off.
• Temperature: tropical and temperate species have different ranges. Marine heatwaves can exceed local tolerances and trigger large meadow losses.
• Nutrients: seagrasses need nitrogen and phosphorus, often absorbed through roots, but excessive nutrient loading stimulates phytoplankton, epiphytes and macroalgae that shade the leaves.

Plant structure, reproduction and meadow formation

Rhizomes spread horizontally through sediment and produce repeated shoots, allowing a single genetic individual to form a very large clone. Roots anchor the meadow and absorb nutrients from sediment. Seagrasses also reproduce sexually through flowers, fruits and seeds; pollen is transported through water, a rare adaptation called hydrophilous pollination. Fast-growing pioneer species can colonise disturbed sediment, while slower, larger species form persistent meadows when conditions remain stable.

Seagrasses as ecosystem engineers

• Leaves slow waves and currents, reducing near-bed turbulence.
• Roots and rhizomes bind sediment and limit erosion.
• Slower water allows suspended particles to settle, improving clarity and creating a positive feedback that favours more plant growth.
• Meadows trap organic matter and bury carbon in oxygen-poor sediment.
• Leaves and sediments cycle nutrients, release oxygen during photosynthesis and provide surfaces for algae and small invertebrates.
• By stabilising shallow seabeds, seagrasses influence lagoon morphology, tidal flats and the sediment supplied to nearby beaches and reefs.

Biodiversity and food-web importance

Seagrass leaves, epiphytes and detritus support fish, prawns, crabs, molluscs and microscopic organisms. Meadows are nursery grounds for many commercial fisheries. Dugongs, manatees and green turtles graze directly on the plants, while seahorses and juvenile reef fish use the blades for shelter. Animals often move daily or seasonally between seagrass, mangrove and coral habitats, linking the whole coastal food web.

Threats and the mechanism of meadow collapse

• Eutrophication: sewage and fertiliser stimulate phytoplankton, epiphytes and macroalgae; shading reduces photosynthesis until roots and rhizomes exhaust stored energy.
• Sediment runoff: deforestation, construction and river-basin erosion make water turbid and can bury leaves.
• Dredging and reclamation: directly remove habitat and create long sediment plumes.
• Fishing and boating: bottom trawls, anchors, propellers and vessel groundings tear rhizomes and create scars that enlarge through erosion.
• Altered freshwater flow: dams, diversions and drought can change salinity, temperature and nutrient conditions in estuaries and lagoons.
• Climate change: marine heatwaves, stronger storms, sea-level rise and changing rainfall shift suitable habitat. Deeper water also reduces seabed light unless meadows can migrate landward.
• Disease and low oxygen: pathogens, decaying algal blooms and sulphide-rich sediment can weaken or kill plants.

Once vegetation is lost, waves resuspend exposed sediment, water becomes murkier and recovery becomes harder. This turbidity feedback can lock a former meadow into a bare, unstable state and may release carbon that had been stored for centuries.

Conservation and restoration

The first priority is to remove the cause of decline: improve water quality, control sediment runoff, protect shallow habitat, regulate dredging, install environmentally safe moorings and prevent propeller damage. Restoration may use seeds, plugs, shoots or biodegradable anchoring structures, but planting succeeds only where light, salinity, hydrodynamics and sediment conditions are suitable. Large connected meadows and natural seed sources should be protected before expensive restoration is attempted.

India: important regions and species

• Gulf of Mannar and Palk Bay: India’s best-known tropical seagrass landscape and a major dugong feeding ground.
• Lakshadweep: lagoon meadows associated with coral atolls and carbonate sand.
• Andaman & Nicobar Islands: sheltered bays, reef flats and island lagoons with diverse tropical species.
• Gulf of Kachchh: intertidal and shallow-subtidal beds exposed to large tides and salinity variation.
• Chilika and other east-coast lagoons: brackish-water meadows shaped by seasonal river inflow, tidal exchange and sediment.

Common Indian genera include Halophila, Halodule, Cymodocea, Thalassia and Enhalus. The dugong is an important flagship species because its survival depends on connected, productive seagrass habitat.

Meadows cover under 0.2% of the ocean floor but bury an estimated 10–18% of all ocean carbon, up to 35× faster than a rainforest. They are the sole food of the dugong and feed green turtles and manatees. The world’s largest plant is a single seagrass clone in Shark Bay, ~180 km across and ~4,500 years old. Yet roughly 30% of seagrass has been lost since the late 1800s. India’s richest beds — and its dugongs — are in the Gulf of Mannar and Palk Bay.

Blue carbonWhy they matter together

“Blue carbon” is the carbon stored by coastal vegetated ecosystems — mangroves, seagrasses and salt marshes. The IPCC notes these can hold up to 1,000 tonnes of carbon per hectare, far more than most land ecosystems, because it accumulates in waterlogged soils that decay slowly. Protecting and restoring them is a genuine natural climate solution; destroying them releases centuries of stored carbon. Modern conservation — Ramsar wetlands, marine protected areas, ICZM, the 30×30 target, ICRI and the Mangrove Alliance for Climate — increasingly manages the whole coastal mosaic as one.

Test Yourself: MCQs

Frequently Asked Questions

What is “blue carbon”?

Blue carbon is the carbon captured and stored by coastal vegetated ecosystems — mangroves, seagrasses and salt marshes. They can hold up to 1,000 tonnes of carbon per hectare, mostly locked in waterlogged soils where it decays very slowly, which makes protecting them a powerful natural climate solution.

How do the three ecosystems depend on each other?

Mangroves trap sediment so seagrass gets clear water; seagrass and mangrove roots stabilise the seabed; offshore reefs break the swell to create the calm lagoon both need. Fish and prawns move between all three across their life cycle.

Are seagrasses the same as seaweed?

No. Seaweeds are algae. Seagrasses are true flowering plants (angiosperms) with roots, veins, flowers and pollen — about 72 species live fully submerged in seawater.

Why are coral reefs called the rainforests of the sea?

Reefs cover under 1% of the ocean floor but shelter roughly 25% of all marine species and support over a billion people — a concentration of life comparable to a tropical rainforest.

What is coral bleaching, and what is happening now?

When water gets too warm, corals expel the algae (zooxanthellae) that feed and colour them, turning white and risking starvation. The fourth global bleaching event (2023–2025), confirmed by NOAA and the ICRI in April 2024, was the largest on record, affecting about 84% of the world’s reef area before ending in mid-2025.

Where are these ecosystems found in India?

Coral: Gulf of Mannar, Gulf of Kachchh, Lakshadweep and the Andaman & Nicobar Islands. Mangroves: 4,991.68 km² (ISFR 2023), led by West Bengal’s Sundarbans and Gujarat. Seagrass and dugongs: the Gulf of Mannar and Palk Bay.

What is the MISHTI scheme?

MISHTI (Mangrove Initiative for Shoreline Habitats & Tangible Incomes), launched in the 2023–24 Union Budget, aims to restore about 540 km² of mangroves across nine states and three union territories by 2028, backing India’s pledge to the COP27 Mangrove Alliance for Climate.

Key References

Global assessments & reports

Global Mangrove Alliance (2024) — The State of the World’s Mangroves 2024.

Bunting, P. et al. (2022; v4.0, 2024) — Global Mangrove Watch: 2020 global mangrove baseline. Remote Sensing.

FAO (2023) — The World’s Mangroves 2000–2020.

NOAA Coral Reef Watch & ICRI (2024–25) — Fourth Global Coral Bleaching Event.

IPCC (2019) — Special Report on the Ocean and Cryosphere (SROCC).

Forest Survey of India (2023) — India State of Forest Report (ISFR) 2023.

Peer-reviewed studies

Fourqurean, J. W. et al. (2012) — Seagrass ecosystems as a globally significant carbon stock. Nature Geoscience 5, 505–509.

Waycott, M. et al. (2009) — Accelerating loss of seagrasses across the globe. PNAS 106(30), 12377–12381.

Short, F. T. et al. (2011) — Extinction risk assessment of the world’s seagrass species. Biological Conservation.

Edgeloe, J. M. et al. (2022) — Extensive polyploid clonality in Posidonia australis, Shark Bay. Proc. R. Soc. B 289.

Hughes, T. P. et al. (2017) — Global warming and recurrent mass bleaching of corals. Nature 543, 373–377.

Spalding, M. et al. (2010) — World Atlas of Mangroves. Earthscan / ISME.

Sources & Data

Data note: Figures reflect the latest global assessments (GMW v4.0 2024, NOAA/ICRI 2023–25, ISFR 2023) and are rounded. Marker positions indicate ecosystem provinces, not exact boundaries — pair with a standard atlas.