Why wetlands are so important #WorldWetlandsDay

In case you were note aware, today (2 February) is World Wetlands Day. As a freshwater aquatic scientist currently working in lentic systems,  I am overly passionate about wetlands and the services they provide. As a major player in the hydrological cycle, their protection is key to sustainable freshwater management. Apart from the hydrological aspects, they also provide unique freshwater ecosystems that are home to many endangered species.

As was eloquently said by Carlos on the Magic School Bus:

The swamp [wetland] is much more than water and mud and plants… and all the different plants help to filter out stuff, like oil, and gunk

What that means is that wetlands act as a natural filter; a water filtration plant for the hydrologic cycle, if you will. The slow movement of water through wetlands combined with the presence of vegetation acts as a sediment trap. Sediment is bits of dirt and/or particulate matter that is commonly found in water. While not inherently a bad thing, sediment is often is found combined with different sorts of contaminants such as harmful bacteria or heavy metals. These sediments are able to settle out in wetlands and micro-organisms are then able to get to work, feasting on the very materials that we consider contaminants. The result is cleaner water for all!

Again from the hydrologic perspective, wetlands also act as a sponge, storing excess moisture during wet periods and providing a source of clean water during drier periods. They also help to replenish ground water by allowing infiltration of surface water into the underlying substrate. Groundwater is often used as a source for direct human consumption, industrial processes, irrigation and can also help to maintain surface water flow during the low-flow periods of the year. With extreme weather events predicted to continue increasing in frequency, the ability for wetlands to help decrease the peak flow during surface runoff events is becoming an increasingly important part of flood-mitigation. For this reason (among others), we are seeing a push to restore historical wetlands that have been damaged or lost, especially in the prairie provinces of Canada.


In addition to the hydrologic value that wetlands provide, they also are home to many unique species of plants and animals. There are many endemic species that live solely in this ecologically-rich environments. There are also many species of fish and reptiles that spend the initial periods of their life in wetlands. As such, wetlands also are a key part of the larger food web, providing animals further up the food-chain with much needed sustenance. The loss of wetlands, and as such, key low-trophic level organisms affects the entire food chain.

Over and above all the scientific reasons for caring about wetlands, there’s also the human use aspect. As illustrated by numerous people on Twitter, wetlands provide a location for recreation and enjoyment. This can include nature walks, fishing, hunting and birding, among numerous other activities.

Wetlands are very environmentally sensitive areas that are key components of freshwater ecosystems. They’re more important than most people think! So if nothing else, in honour of World Wetlands day, try and get out to one soon. You’ll be amazed at the diversity of plants and animals you’ll find thriving – even in the winter!

*footnote: This is meant to be a broad, non-scientific summary of a few of the key ecosystem services wetlands provide. There’s lots more info that can be found. If you want to dive further into it, check out some of the links below:
State of Washington Department of Ecology
The role of wetlands in the Hydrologic cycle, Bullock and Acreman (2003)
Seven important things to know about wetlands – Canadian Geographic
Importance of wetlands to endangered and threatened species, Williams and Dodd (1978)