Coastal wetlands, tides, salt-tolerant plants, estuaries, mud, nursery habitat, fisheries, blue carbon, storm buffering, water filtration, sediment trapping, sea level rise, marsh migration, restoration, and coastal resilience
Salt marshes
Salt marshes are coastal wetlands flooded and drained by tides, where salt-tolerant plants build habitat between land and sea.
What salt marshes are
Salt marshes are tidal coastal wetlands found along sheltered shorelines, estuaries, bays, and lagoons. They are flooded and drained by tides and are usually covered by salt-tolerant grasses, rushes, sedges, and low plants rather than trees.
How tides shape them
Tides bring salt water, sediment, nutrients, and organisms into the marsh. As water slows among plant stems, sediment can settle and organic matter can build soil, helping the marsh maintain elevation.
Life in salty soil
Salt marsh plants tolerate salinity, waterlogged soils, and low oxygen around their roots. Their stems and roots slow water, hold soil together, and create structure for insects, crabs, snails, fish, and birds.
Nursery habitat
Many fish, shrimp, crabs, and other species use salt marshes for food, shelter, spawning, or juvenile growth. Marsh creeks and edges can provide safer, food-rich habitat before animals move into deeper estuary or ocean waters.
Water filtration
Salt marshes can trap sediment, take up nutrients, and slow runoff before it reaches bays or coastal waters. This helps maintain water quality, although marshes can be overwhelmed by too much pollution or sediment stress.
Storm and erosion buffering
Marsh vegetation and shallow platforms can reduce wave energy, stabilize shorelines, and give floodwater room to spread. They do not stop every storm, but they can reduce damage when combined with smart land-use planning.
Threats and restoration
Salt marshes are threatened by filling, drainage, development, sea level rise, erosion, invasive species, pollution, and blocked tidal flow. Restoration may reopen tides, add sediment, remove barriers, control invasives, or create space for marsh migration.
Why it matters
Salt marshes sit at the working edge of land and sea. They support biodiversity, fisheries, cleaner water, carbon storage, coastal protection, and cultural landscapes, making them valuable natural infrastructure for changing coasts.