How Wetlands Support our Watershed

Wetlands are important features of our natural landscape, providing numerous benefits for people and wildlife. These highly productive and diverse ecosystems enhance water quality, control erosion, maintain stream flows, and provide valuable habitat.

A wetland is a land area that is saturated with water, either permanently or seasonally, such that it takes on the characteristics of a distinct ecosystem. The primary factor that distinguishes wetlands from other land features or water bodies is the vegetation adapted to their unique soil conditions. Wetland systems are not identical; they can include swamps, marshes, bogs, or fens, and may be freshwater, saltwater, or brackish. Wetlands range from the iconic mangroves of Biscayne National Park in Florida to the riparian zone of the Madison River at its confluence with Ennis Lake.

Given the diversity of wetlands throughout the world, it can be difficult to assign a single value to an individual wetland. However, we can evaluate how wetlands function to better understand their significance. Wetlands act as natural sponges, storing water and slowly releasing it over time. This function is especially valuable during periods of drought, as wetlands absorb water during wet periods and gradually release it during dry periods. By slowing the movement of water, wetlands reduce erosive potential, recharge groundwater, and decrease flood risk.

Wetlands also play an important role in water quality. As water slows and moves through plant communities, sediments suspended in the water often settle on the wetland floor. Other pollutants, such as nutrients from wastewater seepage or agricultural operations, can be taken up by plants, further improving water quality.

In addition to improving water storage and quality, wetlands are among the most biologically productive environments in the world. Shallow waters and extensive plant communities provide essential habitat for fish and wildlife. One of my favorite wetland visitors in the Madison Valley is the yellow-headed blackbird, often seen perched on cattails in the summer. More than one-third of the United States’ threatened and endangered species live exclusively in wetlands, and nearly half depend on wetlands at some point in their life cycle. Aquatic plant life also flourishes in these nutrient-rich environments.

Recognition of the importance of wetlands gained international attention in 1971, when representatives from around the globe gathered at the Ramsar Convention, also known as the Convention on Wetlands, on February 2nd. This meeting resulted in the signing of an intergovernmental treaty aimed at preventing wetland loss worldwide. In 1997, the first World Wetlands Day was celebrated on February 2nd, marking the 25th anniversary of the convention.

Despite this growing recognition, wetlands have not always been valued. As transition zones between land and water, wetlands were often viewed as wastelands, with more perceived value in draining or filling them for development. Some were even used as dumping grounds. A 1990 study by the U.S. Fish and Wildlife Service revealed that more than half of the 221 million acres of wetlands that existed in the continental United States in the late 1700s had disappeared. In Montana, approximately one-third of wetlands have been drained or filled. While awareness of wetland importance has increased, these “nurseries of life” are still disappearing at a substantial rate. The primary drivers of wetland loss in the 21st century include development, agriculture, and a changing climate.

Interested in learning more about Montana’s wetlands? The Montana Natural Heritage Program, part of the Montana State Library’s Natural Resource Information System, works to create a statewide digital wetland and riparian layer to support management, planning, and restoration efforts. With support from the Montana Wetland Council and other partners, the program maps wetlands and riparian areas according to National Wetlands Inventory (NWI) standards. To explore currently mapped wetland areas, visit:
https://mtnhp.mt.gov/resources/ecology/wetlands/