Restore Ecosystems - Tidal Flats

Tidal flats —intertidal areas of mud, sand, and mixed sediments—are among the most threatened coastal ecosystems, frequently lost to land reclamation, dredging, and coastal development.

These intertidal areas of mud and sand provide critical ecosystem services, including nutrient cycling, carbon storage, coastal protection, and habitat for migratory birds, fish, and invertebrates.

Losing tidal flats carries significant ecological and economic consequences, as tidal flats support food security, fisheries, and carbon sequestration that contribute to climate mitigation. Despite their importance, global monitoring is limited, and restoration efforts remain fragmented.

Key Stats

Tidal Flat Extent

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Globally, tidal flat ecosystems have decreased 3.3% between 1985 and 2015.

Tidal Flats Score Data

Data Frequency

35Years
Data Quality

Sufficient – At least 2 data points available for trend analysis AND at least one data point in the last 7 years
Geographic Range

100% of global data available
Global Goal(s)

Global Goal(s)

Data Availability

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Tidal flats face pressures from urban expansion, damming of estuaries, and rising sea levels.

Many tidal flats are being lost faster than coral reefs and mangroves, especially in Asia and Europe, where coastal modification is widespread. Climate change is compounding these pressures, as sea-level rise outpaces natural sediment accumulation.

Although international frameworks like Ramsar designations, migratory bird treaties, and coastal zone management policies provide tools for protection, monitoring remains a major challenge. The dynamic and shifting nature of tidal flats makes them difficult to assess and manage using traditional tools. Coordinated global action is urgently needed to track their extent, address human pressures, and enhance ecosystem resilience in the face of climate change.

Extent and Change

Explore where tidal flats are most prevalent and how those habitats are changing.

Extent & EEZ

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There are approximately 127,921 km² of tidal flats globally—100% of which lie within national EEZs.

Tidal Flat Net Change

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Globally, tidal flat ecosystems have gained 6,647 km² and lost 6,916 km² resulting in a net change of -268 km² between 1999 and 2019.

Threats and Risks

Track the pressures driving tidal flat loss.

Sea Level Rise

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Globally, approximately 22% of tidal flats lie within areas experiencing high sea level rise.

Explore Sea Level Rise

Protection and Restoration

See where tidal flats are safeguarded.

Protection

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Globally, approximately 31% of tidal flats lie within established protected areas.

Explore Protected Areas

Protecting and restoring tidal flats maintains critical feeding and breeding grounds, buffers coastal zones against erosion, improves water quality, sequesters carbon, and sustains fisheries and agriculture.

Taking Action

Protect Existing Tidal Flats

Preserving the current extent of tidal flats through conservation laws and the expansion of marine protected areas is essential. Long-term management and enforcement of these areas are critical to preventing further degradation.
Restore Hydrological Flows

Reconnecting tidal flats to natural water systems by modifying or removing barriers, such as levees and dams, can restore tidal cycles, sediment transport, and ecosystem health.
Control Erosion

Nature-based solutions, such as living shorelines, can stabilize tidal flats and prevent further erosion.

Manage Sediment

Adding sediment to degraded tidal flats can restore their elevation and support the growth of vegetation, including salt marshes and mangroves, which reinforce the ecosystem.
Mitigate Climate Change Impacts

Incorporating tidal flats into climate strategies as valuable blue carbon sinks and planning for their landward migration through managed retreat can help them persist amid rising sea levels.
Land-Use and Marine Spatial Planning

Coastal zoning that considers tidal flat restoration and managed retreat is vital for meeting global restoration targets.

Engage Local Communities

Involving local communities in restoration efforts ensures long-term success and aligns ecological goals with community livelihoods.
Financial Incentives

Innovative financial mechanisms, such as payments for ecosystem services and blue carbon markets, can encourage the protection and restoration of tidal flats.
Strengthen Policies

National and international policies must align to facilitate tidal flat restoration. Linking restoration efforts to the UN Sustainable Development Goals can enhance global commitment.

Research and Monitoring

Mapping the global extent of tidal flats and supporting research into restoration practices are crucial steps for long-term protection.
International Collaboration

Cross-border partnerships among governments, NGOs, and international bodies will ensure coordinated global action in protecting and restoring tidal flats.

Case Studies 1

East Sea
Getbol – Korean Tidal Flats World Heritage Site

Designated as a UNESCO World Heritage Site in 2021, Getbol (Korean Tidal Flats) represents the world’s largest remaining tidal flat system and one of the planet’s most important ecological corridors for migratory birds along the East Asian–Australasian Flyway. Spanning four distinct tidal flat types—estuarine, open embayed, archipelago, and semi-enclosed—Getbol demonstrates exceptional geological diversity and supports more than 2,169 marine and coastal species, including 27 globally threatened bird species such as the critically endangered Spoon-billed Sandpiper. Historically, over 65% of tidal flats in the Yellow Sea were lost due to land reclamation from the 1950s through the early 2000s. However, since 2018, Korea has undergone a major policy shift, adopting national legislation such as the Getbol Act (2020) and restoration plans under the Master Plan for Tidal Flat Conservation and Restoration (2021–2025) to reverse habitat loss.

These initiatives include large-scale removal of marine debris, control of invasive species such as Spartina alterniflora, restoration of high-tide roosting areas, and the integration of citizen science for migratory bird monitoring. The conservation of Getbol is not only a biodiversity imperative—it is vital for climate resilience: tidal flats in this region store significant amounts of blue carbon, protect coastal communities from storm surges, support traditional fisheries, and maintain nutrient cycles that sustain food security across East Asia. By positioning tidal flats as living infrastructure for climate mitigation and adaptation, the Getbol initiative is emerging as a global model for coastal ecosystem restoration in the face of sea-level rise and development pressure.

Ministry of Oceans and Fisheries (Republic of Korea); UNESCO World Heritage Committee; Local Governments (Seocheon, Gochang, Shinan, Boseong–Suncheon); Korean Marine Environment Management Corporation; Community Stakeholder Groups and Citizen Science Initiatives.
worldheritageoutlook.iucn.org

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Restore Ecosystems - Tidal Flats - Ocean Central

Tidal flats —intertidal areas of mud, sand, and mixed sediments—are among the most threatened coastal ecosystems, frequently lost to land reclamation, dredging, and coastal development.

Key Stats

Tidal flats face pressures from urban expansion, damming of estuaries, and rising sea levels.

Protecting and restoring tidal flats maintains critical feeding and breeding grounds, buffers coastal zones against erosion, improves water quality, sequesters carbon, and sustains fisheries and agriculture.

Taking Action

Case Studies 1