What are Wetlands and Why Do We Need Them?


There is a variety of wetlands with different compositions of plants and animals, but they all share general characteristics, including poorly drained soils, hydrophytic (water-loving) vegetation, and various kinds of biological activity which are adapted to a wet environment. More specifically, wetlands include five primary freshwater types: bogs and fens (both are peatlands), swamps, marshes, and shallow open waters such as sloughs, ponds, and pot holes.

Wetland: area of land covered by shallow water or saturated by water – National Geographic

Why do we need wetlands?

Wetlands are one of the most productive ecosystems on the planet and are important for a number of reasons.

1. Wetlands prevent floods and drought

Wetlands can act as natural flood prevention systems, capable of absorbing massive amounts of water during storms and guarding against erosion. By holding soils in place with their roots, wetland plants absorb the energy of waves, and break up the flow of stream or river currents.

During the wet season, wetlands soak up excess rain, snow, and surface water. In drier seasons, wetlands not only provide wildlife habitat, but also slowly release their stored waters into underground aquifers and streams. Wetlands are the source of groundwater recharge for many aquifers that serve as community water supplies.

2. Wetlands filter water

Wetlands act as natural filters, removing sediment and pollutants from the water. The primary way that wetlands filter water is by slowing the flow of water from the surrounding land, thereby preventing erosion and enabling the wetland plants more time to absorb the nutrients being carried by the water. This slowing of the flow also allows suspended sediment to settle to the bottom of the wetland, sending clearer water downstream.

3. Wetlands support rare animals and plants

Great basin spadefoot (toad)

Wetlands play a disproportionately important role among ecosystems in providing food, shelter, and safety for wildlife species. It is estimated that more than 50% of wildlife species in North America rely on access to wetland habitat for at least part of their lifecycles, and almost 35% of all rare, threatened, and endangered wildlife species are dependent on wetland ecosystems.

4. Wetlands store carbon

Wetlands sequester carbon from the atmosphere through plant photosynthesis. That carbon is held in the living vegetation as well as in litter, peats, organic soils, and sediments that have built up, in some instances, over thousands of years, playing a key role in regulating greenhouse gases and buffering the impacts of climate change.

The worrying state of wetlands

Regardless of their many values, wetlands have been converted to other uses at a rapid rate. Wetlands are filled to make way for housing and industry, are diked, drained and polluted by poor agriculture practices, and are dried through the construction of dams, roads and pipelines, limiting and often irreversibly altering wetland hydrology and habitats. Factor in increasing climate change impacts, and without protection and conservation, wetlands are severely at risk.

Photo: Katelyn Bissat

How we can help

  • Visit and appreciate the diversity in your local wetlands.
  • Participate in environmental stewardship initiatives, such as tree and shrub planting and litter clean-ups.
  • Support wetland conservation and citizen science initiatives.
  • Get informed!

Feature photo: Katelyn Bissat