Don't drain the swamp! Why wetlands are so important

Donald Trump has claimed that he wants to "drain the swamp" in Washington. But in the ecological world, draining swamps is a really bad idea.

From fighting climate change to sheltering birds, wetlands are crucial to the planet's health

Wetlands, like this peat bog near Ottawa, are incredibly effective at sequestering carbon - helping fight climate change. (Flickr / CJuneau)

Donald Trump has claimed that he wants to "drain the swamp" in Washington. The president is talking about politics, of course. But in the ecological world, draining swamps is a really bad idea. 

Swamps — more correctly known as wetlands — are an incredibly important global ecosystem. So today, on World Wetlands Day, let's show them some love. 

What makes a 'wetland'?

Wetlands are defined as areas that are covered in water for at least one season. They're often full of plants called hydrophytes: the ferns, sedges and rushes that we typically associate with wet, swampy, boggy areas. These plants love soils that are saturated with water.

But there are many different types of wetlands. There are bogs that are full of peat mosses, marshes at the mouths of rivers and lakes, coastal wetlands where mangrove trees grow and countless other examples. 

Mangrove forests are one of the wetland ecosystems that are most in danger from human activities. (Giuseppe Di Carlo/Conservation International)

Why are they so important?

Let me count the ways…

One reason is that wetlands act as natural water filters. When runoff from natural and man-made processes pass through, wetlands can have a neutralizing effect.  

If wetlands are in between an agricultural zone and a freshwater ecosystem, fertilizer runoff is absorbed by the wetland and used to fuel the slow processes that take place there. By the time the water reaches a lake or stream, there isn't enough fertilizer left to fuel the destructive algal blooms that can poison freshwater ecosystems.

Another big reason wetlands are important is that they are one of the most productive ecosystems on the planet.

Wetlands are the world's nurseries. Young fish escape predation by hiding amongst the roots and shoots of wetland plants like mangroves. Birds from all over the world use the dense greenery to hide their nests. The 'prairie potholes' of Manitoba, Saskatchewan and Alberta are important areas for migrating birds.

More than half of North America's waterfowl nest in 'prairie potholes,' small patches of wetland that dot the prairies of Canada and the U.S. (Flickr / USFWS Mountain-Prairie)

How do they help the environment?

It's simple: wetlands help fight climate change. 

A new study published today in Frontiers in Ecology and the Environment looks at the impact that wetlands can have in mitigating man-made global warming. These areas are able to break down organic material very slowly and without oxygen, storing carbon rather than releasing it into the atmosphere. 

Peat bogs — of which Canada has many — are especially good at storing carbon. Bogs are an incredible natural phenomenon that can take take hundreds or thousands of years to develop.

Bogs have a very low pH, which means that dead, decaying plant matter takes a very long time to decompose. So any of the carbon trapped in plants goes down into the ground and is not metabolized into carbon dioxide. Peat bogs or muskeg contain an estimated one-third of the organic carbon in global soils.

In coastal wetlands, carbon is taken up via photosynthesis, where it gets sequestered into woody biomass and soil (red dashed arrows) or respired (black arrows). (Frontiers in Ecology)

How extensive are wetlands in Canada?

We find wetlands across the entire country. Twenty-one per cent of Alberta is classified as wetland. Even small Prince Edward Island is home to wetlands — St Peter's Lake Run is a very important marsh for a bird called the piping plover.

But wetlands are disappearing too. Sixty-eight per cent of Ontario's natural wetlands have been destroyed in favour of agricultural lands or other development. Only about 25 per cent of southern Manitoba's wetlands remain.

That being said — wetland cover in Canada is still substantial. Most of the north's natural wetlands are still intact.

How can wetlands be protected? 

For starters, recognizing that just because the land is soggy and unusable for humans does not mean it is not important. In Canada there is a growing awareness about the importance of wetlands, but they always seem to get in the way of someone's attempt to make money.

There are some basic consumer choices you can make to preserve wetlands — an easy one is to look at your shrimp packaging. 

Most of the inexpensive shrimp that you find on grocery store shelves comes from farms in Indonesia and Vietnam where mangrove forests are removed in favour of large-scale shrimp ponds. The ponds last only about 10 years, so companies will then move down the coast, destroy more mangroves and start over.

Conservation isn't actually that hard, but it starts with understanding and being aware of just how important these ecosystems really are.

Happy World Wetlands Day! 


Torah Kachur

Science Columnist

Torah Kachur is the syndicated science columnist for CBC Radio One. Torah received her PhD in molecular genetics from the University of Alberta and now teaches at the University of Alberta and MacEwan University. She's the co-creator of


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