Tidal Flats - Ocean Central
Tidal Flats
Tidal flats, or mudflats, are coastal landforms consisting of sediments deposited by tides and rivers, found where marine, freshwater, and land environments meet.
These ecosystems typically form in low-slope areas with regular tidal flooding. Tidal flats are composed of mud, sand, and organic material, becoming exposed during low tide and submerged at high tide. Although the global extent of tidal flats remains unmapped, the Wadden Sea, a UNESCO World Heritage Site, is the largest connected tidal flat system, spanning approximately 500 km and covering an area of 10,000 km² — about the size of Jamaica.
Key Benefits of Tidal Flats
-
Carbon Sequestration
Similar to salt marshes, seagrasses, and mangroves, tidal flats capture and store “blue carbon,” which is carbon captured by coastal ecosystems. Organic materials within these ecosystems trap carbon for long periods, helping mitigate climate change.
-
Coastal Protection
Tidal flats serve as natural coastal defenses, absorbing wave energy and protecting shorelines from erosion. During storm surges and high tides, tidal flats can absorb excess water, reducing the risk of flooding.
-
Biodiversity Enhancement
These habitats are critical for many species, including shellfish, crabs, and fish. Tidal flats also provide feeding and breeding grounds for migratory birds and other coastal wildlife.
-
Water Quality Improvement
Tidal flats filter pollutants and recycle nutrients, such as nitrogen and phosphorus, contributing to healthier ecosystems and cleaner coastal waters.
-
Sustaining Fisheries and Aquaculture
Tidal flats support important fishing and aquaculture industries, serving as nursery grounds for commercially valuable fish and shellfish species. Coastal communities rely on these ecosystems for food and employment opportunities.
-
Recreation and Ecotourism
Tidal flats attract ecotourists for activities such as birdwatching and mudflat hiking, offering recreational and educational experiences.
-
Cultural and Educational Importance
In many regions, tidal flats have deep cultural significance, serving as traditional fishing and harvesting grounds for coastal communities. Additionally, tidal flats provide rich opportunities for scientific research and environmental education.
Pressures on Tidal Flats
-
Coastal Development
Urbanization and infrastructure projects along coastlines lead to habitat loss and fragmentation of tidal flats, threatening their long-term viability.
-
Pollution
Agricultural runoff, industrial waste, and plastic pollution degrade water quality and harm the organisms that inhabit tidal flats. Oil spills and chemical contaminants further threaten these ecosystems.
-
Hydrological Changes
Dams and other water control structures reduce freshwater and sediment inflows, negatively impacting the health of tidal flats and the species that depend on them.
-
Climate Change
Rising sea levels and more frequent storms, driven by global warming, pose significant threats to tidal flats. These ecosystems are at risk of permanent submersion and erosion.
-
Overharvesting and Overfishing
Intensive shellfishing and sand mining can deplete key species and destabilize the ecological balance of tidal flats.
-
Invasive Species
The introduction of non-native species, such as invasive crabs or plants, disrupts the natural biodiversity and functioning of tidal flat ecosystems.
Taking Action to Restore Tidal Flats
-
Protecting Existing Tidal Flats
-
Restoring Hydrological Flows
-
Erosion Control
-
Sediment Management
-
Mitigating Climate Change Impacts
-
Land-Use and Marine Spatial Planning
-
Engaging Local Communities
-
Financial Incentives
-
Strengthening Policies
-
Research and Monitoring
-
International Collaboration
Credits
- Carlos Duarte
- Vanesa Chalastani
- Letizia Valluzzi