Marsh

A marsh is a type of wetland where the soil is regularly or permanently saturated with water. It may be found beside rivers and lakes, along coasts, or in shallow depressions where water collects. Unlike a swamp, which is often dominated by trees and shrubs, a marsh is mainly covered by grasses, reeds, sedges and other plants adapted to wet conditions.

The water can be fresh, salty or somewhere in between, depending on its location and the sources that feed it. Some marshes remain wet throughout the year, while others become much drier during part of the year. Their appearance can therefore change with rainfall, tides, river flow and seasonal water levels.

Marshes are important ecosystems because they provide food, shelter and breeding areas for many organisms. Birds, fish, amphibians, insects and small mammals can all depend on them, while their dense vegetation offers places to hide and reproduce. Marshes also perform useful natural functions: their plants and soils can trap sediments and absorb some pollutants, and wetland soils can store large amounts of carbon.

Coastal marshes can help reduce the force of waves and flooding, while river and inland marshes can temporarily hold excess water. Despite these benefits, many marshes have been drained, filled or altered for farming, construction and other human activities. Protecting them helps preserve biodiversity and the natural processes that support healthy landscapes.