Coastal Wetlands

Estuaries and coastal freshwater wetlands have been significantly altered by urbanization, development, and industrialization, putting species at risk and decreasing the resilience of human communities. These habitats have been significantly reduced or degraded in most areas outside of Alaska and northern British Columbia. Additional threats include introduced and invasive species and pollution.

Efforts to protect and restore coastal wetlands are critical to slow or reverse the decline of coastal birds. Birds that overwinter in coastal areas are facing the steepest proportional losses; a third of shorebird species have experienced cumulative population losses exceeding 70% since 1980.

As we look to the near future, sea level rise and increased flooding and storm surge will dramatically alter coastlines – and how people and wildlife use coastal lands and waters.

Coastal wetlands encompass a variety of habitats, including estuaries, tidal and subtidal flats, marshes, swamps, and freshwater wetlands, all unique and productive environments. These habitats serve as vibrant feeding grounds and nurseries for numerous species of birds, fish, mammals, invertebrates, and other wildlife.

Across the northern Pacific Flyway and beyond, coastal wetlands form a critical network of stopover sites for millions of migratory birds, which they use to breed, rest, refuel, and overwinter. When these habitats are lost or degraded, migratory birds lose vital parts of this network and have fewer safe places to land.

Coastal wetlands play an essential role in reducing the impacts of climate change, acting as natural buffers against storms, flooding, and sea level rise, by helping to absorb and dissipate the energy of waves, and by holding excess water during heavy rains and high tides. Wetland vegetation helps stabilize soil and prevent erosion along coastlines. Vegetated coastal habitats also efficiently trap suspended organic matter during tidal inundation, capturing carbon at a rate ten times greater than tropical forests.

Coastal wetlands hold significant cultural value to Indigenous Peoples and local communities and are important for spiritual practices and well-being, cultural heritage, traditional harvests, and subsistence. Coastal wetlands also sustain commercial fisheries and shellfish farms and support recreational tourism. In addition, they provide several vital ecosystem services, improve water quality, and maintain the health of coastal ecosystems by filtering pollutants, sediment, and excess nutrients from water before it enters the ocean.