Seagrass

Often mistaken for seaweed, seagrasses differ by rooting themselves into the seabed, thriving in shallow coastal waters like bays, lagoons, and estuaries. Found across 159 countries, these ecosystems cover over 300,000 km² — an area roughly the size of Italy. However, these vital habitats are poorly mapped, limiting our full understanding of their global extent.

Seagrass by the Numbers

18% of Ocean Carbon Sequestered

Seagrass meadows sequester up to 18% of the ocean’s carbon, despite covering just 0.1% of the seafloor, highlighting their critical role in climate regulation.
Found in 159 Countries Worldwide

Seagrass meadows are distributed across 159 countries on every continent except Antarctica, illustrating their global significance in marine ecosystems.
29% Decline Since 1879

Since 1879, the global area of seagrass has decreased by approximately 29%. However, some regions have begun to see a reversal of this trend since the 2000s, indicating potential for recovery.
Nursery Habitat for 20% of Major Fisheries

Seagrasses provide essential nursery habitats for over 20% of the world’s largest 25 fisheries, underlining their importance in supporting global fish populations.
30% Restoration Goal

Restoring 30% of seagrass ecosystems globally requires a coordinated strategy that combines ecological restoration of seagrass meadows with the reduction of harmful human activities that threaten these vital habitats.

Key Benefits of Seagrass Meadows

Carbon Sequestration
Despite covering only 0.1% of the ocean floor, seagrass meadows store up to 18% of oceanic carbon, capturing carbon up to 35 times faster than tropical rainforests. Their sediments never become saturated, allowing continuous carbon storage.
Coastal Protection
Seagrass roots stabilize sediments, acting as natural buffers against erosion, storm surges, and flooding, reducing wave energy before it reaches shorelines.
Ocean Acidification Buffering
Through photosynthesis, seagrasses increase seawater pH, helping to counteract ocean acidification and creating healthier environments for marine life.
Water Quality Improvement
By filtering nutrients, pollutants, and sediments, seagrasses enhance water clarity and quality, benefiting coral reefs and marine life.
Biodiversity Enhancement
Seagrass meadows provide vital habitats for thousands of species, including endangered species like sea turtles, dugongs, and seahorses, supporting rich biodiversity.
Sustaining Fisheries
As nurseries for juvenile fish, these meadows support over a fifth of the world’s major fisheries, contributing significantly to global seafood supplies.
Ecotourism and Recreation
Seagrass meadows attract tourists for snorkeling, diving, and wildlife viewing, offering ecotourism opportunities that bolster local economies.
Economic and Medicinal Benefits
Seagrasses have potential medical uses due to their antibacterial and anti-inflammatory properties. In some cultures, seagrasses have been used for traditional medicine and as material for crafts.

Pressures on Seagrass Meadows

Coastal Development
Climate Change
Water Pollution

Unsustainable Recreation
Overfishing and Trawling
Invasive Species and Disease
Hydrological Changes

Taking Action to Restore Seagrass

Protect Existing Meadows
Seagrass Planting
Support Natural Regeneration
Promote Sustainable Practices
Nature-Based Solutions
Incorporate Seagrass in Climate Strategies

Marine Spatial Planning
Community Engagement
Financial Incentives
Strengthen Policies
Research and Monitoring
International Collaboration

Credits

Carlos Duarte
Vanesa Chalastani
Letizia Valluzzi

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