Though Canada is often known as a land of lakes, it is also a country of wetlands. Stretching like a necklace of emeralds, sapphires and rubies across the Canadian landscape, wetlands cover 14 per cent of the Canadian land mass, accounting for almost twice as much area as lakes.
Canada is home to a quarter of the world’s remaining wetlands, yet they remain like hidden treasures that most Canadians rarely pay a second thought.
The importance of wetlands to a sustainable future has been recognized internationally. Signed in 1971 in the Iranian city of Ramsar, the Convention on Wetlands — often called the Ramsar Convention — supports international collaboration and national action for the conservation of wetlands.
This week, delegations from contracting parties to the convention, including Canada, have come together in Victoria Falls, Zimbabwe, for the 15th Conference of the Parties.
Despite decades of efforts, wetlands continue to be under threat around the world. Delegates will work this week to chart a path forward that further elevates wetlands in the global consciousness, highlighting the need to protect these ecosystems and meet international goals to safeguard biodiversity and slow climate warming.
Canada currently has 37 Wetlands of International Importance under the Ramsar Convention, covering more than 13 million hectares. Yet many of Canada’s wetlands remain unprotected.
Canada’s wetlands
The term “wetland” usually conjures an image of a shallow pond bordered by cattails. In fact, Canadian wetlands come in a range of shapes and sizes, all of which provide valuable services. Those reedy marshes provide critically important habitat and water storage, particularly in the Prairies, southern Ontario and Québec.
The vast majority of Canada’s wetlands are made up of swamps, fens and bogs, most of which also hold deep deposits of organic soils called peat. Bogs and fens can resemble vast mossy carpets. But they can also look a lot like forests, hiding their soggy soils beneath a canopy of trees.
This wetland diversity contributes to their value. At the interface of terrestrial and aquatic ecosystems, wetlands are often biodiversity hotspots.
They are home to weird and wonderful species, including carnivorous plants like sundews, pitcher plants and bladderworts. And if you’re hungry, peatlands are a great place for berry picking.
Interwoven in our boreal landscape, wetlands also support iconic Canadian species like beavers, moose and woodland caribou and are key habitats for waterfowl and other migratory birds.
Preserving wetlands is also a key flood mitigation strategy. Storm water can fill up pore spaces in mossy peat soils, or spread out across the flat expanse of swamps and marshes, reducing peak flows and helping to protect downstream infrastructure. As the water slows, water quality can also be improved. Sediments have time to settle, while plants and microbes can remove excess nutrients.
Carbon storage
In recent decades, wetlands have gained international attention for their role in carbon storage. Waterlogged sediment and soil lead to slow rates of decomposition. When plant litter falls in a wetland, it builds up over time, creating a bank of carbon that can be stored for millennia.
Peatlands are particularly good at accumulating carbon, as they are home to plants that inherently decompose slowly. Because of this, peatlands store twice the carbon of the world’s forests. Keeping this carbon stored in wetland soils, and out of the atmosphere, is important to climate change mitigation.
Yet, the buildup of carbon in wetlands is slow. Many of these ecosystems have been adding to this carbon bank since the last ice age; digging through metres of peat is like travelling back through time, with the deposits at the bottom often thousands of years old.
This means that the carbon stored in wetlands is irrecoverable within human lifetimes. Once lost, it will be many generations before the full value of this treasure can be returned.
The economic value of the water-filtering and carbon storage that Canadian wetlands provide has been estimated at $225 billion per year. It’s clear: healthy wetlands contribute to our society’s well-being.
But just as important, they are an integral component of the Canadian landscape. Wetlands are interwoven with our forests, fields, lakes and now even our cities. They link us to the land and water. They are places of wonder and spiritual connection.
Impact of climate change
Despite their value, wetlands in Canada face many threats. In southern regions of Canada, most wetlands have already been lost to drainage for agriculture and urban development. Further north, up to 98 per cent of Canadian peatlands remain intact.
However, climate change and resource development are already exacerbating wetland disturbance and loss. Warming temperatures have contributed to larger and more severe wildfire that also impact peatlands and lead to large carbon emissions.
Thawing permafrost is further changing wetland landscapes and how they function. Warming also allows for northward expansion of agriculture with the potential for loss of even more wetland area to drainage.
Natural resource extraction further contributes to wetland disturbance, often with unexpected consequences. Geologic exploration used to map oil and gas reserves has left a network of over one million kilometres of linear forest clearing across the boreal forest, much of which crosses peatlands.
This has contributed to declines in woodland caribou populations and led to increases in methane emissions from these ecosystems.
Mining often involves regional drainage or excavation of peatlands, resulting in the loss of their services. The recent push to fast-track production of critical minerals in Canada is putting vast areas of our wetlands at risk.
Wetland restoration research is ongoing, with some promising results. However, given the long time-scale of wetland development, avoiding disturbances in the first place is the best way to safeguard wetlands.
As stewards of a quarter of world’s wetland treasures, policymakers and everyday Canadians need to ensure wetlands are safeguarded and preserved for a prosperous future.
Maria Strack receives funding from the Natural Sciences and Engineering Research Council of Canada, Environment and Climate Change Canada, the Canadian Sphagnum Peat Moss Association, Ducks Unlimited Canada, Imperial Oil Ltd., Alberta Pacific Forest Industries Inc., Cenovus Energy, Canadian Natural Resources Limited, ConocoPhillips Canada, Natural Resources Canada, and the Alberta Biodiversity Monitoring Institute.
