Why have more than half of the original wetlands in the lower 48 U.S. states been lost?

More than half of the original wetlands in the lower 48 U.S. states have been lost primarily due to their conversion into agricultural land.1

Beyond agriculture, human-caused disturbances have significantly contributed to this decline. Wetlands have been systematically drained, diked, dredged, and filled to facilitate urban expansion, building projects, and road construction. Major U.S. cities, including Chicago and Washington, D.C., were built on sites that were once partially covered by wetlands.12

Additional factors driving this loss include:
* Infrastructure Development: The construction of dams has stabilized river flows, radically altering river basins and destroying associated wetlands.2
* Resource Extraction: Logging has removed dominant tree species from various wetland types, while peat mining has removed accumulated organic substrates.2
* Land Reclamation: Techniques such as installing tile lines or digging ditches have been used to remove water from swampy areas to make them suitable for crop production.3

It is ethically imperative to recognize that wetlands are among Earth’s most productive ecosystems, serving as vital habitats and providing essential services like water filtration and flood control. Prioritizing their conservation and restoration is a fundamental responsibility for sustainable development.412