By Mel de Jager and Patrick Lafrance
Canada’s coastlines are at risk due to the impacts of climate change. Rising sea levels threaten coastal communities, putting low-lying areas at risk of being underwater in the decades to come.
Beyond the community impact, there is another important climate change impact that must be addressed when discussing how to protect these coastal areas: Canada’s blue carbon resources.
The Intergovernmental Panel on Climate Change defines Blue Carbon as “… the carbon captured by living organisms in coastal (e.g., mangroves, salt marshes, seagrasses) and marine ecosystems, and stored in biomass and sediments.” Oceans circulate approximately 83% of global carbon, and approximately 50% of the global carbon is stored in ocean sediment. But the primary conversation around blue carbon focuses on coastal lands, which countries like Canada can directly impact.
According to the National Ocean Service in the United States: “Current studies suggest that mangroves and coastal wetlands annually sequester carbon at a rate ten times greater than mature tropical forests. They also store three to five times more carbon per equivalent area than tropical forests.”
These are vital carbon sinks that must be protected along our global coastlines.
Blue Carbon in Canada
The primary blue carbon resources found along Canadian shorelines are seagrasses and tidal marshes.
At the global scale, tidal marshes are being lost at a rate of 1-2% annually. In Canada, the Bay of Fundy salt marshes has seen a loss of 80%, primarily as a result of development, including the construction of dikes. Dikes have been constructed in the region since the 17th century, when early Canadian settlers used them to transform the salt marshes into agricultural land.
Seagrass beds are coastal areas where a variety of seagrasses – submerged, deep-rooted flowering plants – grow. They are one of the most at-risk ecosystems globally, with an increasing loss rate that is currently about 1.5% annually, amounting to nearly 30% of global coverage. In Canada, seagrass beds can be found on all three ocean coastlines (Pacific, Atlantic, and Arctic).
Protecting blue carbon resources ensures that they can continue to sequester and store carbon, and continue to provide various other benefits. Damaging or destroying blue carbon resources not only reduces total carbon sequestration capacity, but also releases the embodied carbon, which can constitute millennia of captured carbon. Current losses of blue carbon ecosystems cause emissions of up to 0.15-1.02 billion tonnes of CO2 annually.
The Blue Caron Initiative, a global program that is “working to mitigate climate change through the restoration and sustainable use of coastal and marine ecosystems,” states that climate change impacts, and man-made activities, are causing harm to both tidal marsh and seagrass volumes. “While both marshes and seagrasses help mitigate climate change impacts, they are also susceptible to its effects. Tidal marshes are most threatened by the rising sea levels associated with global warming, while seagrasses are threatened by the more extreme waves and storms as well as increasing water temperatures. Marshes are severely impacted by costal developments and agriculture, both of which require the marshes to be drained. Seagrasses are impacted by activities that reduce the light levels they receive. These activities include deforestation, dredging, algae growth from fertilizers and pollution, boating, and disturbances of sediment from agriculture and land development.”
Because of these current and historic activities, our blue carbon resources in Canada continue to deteriorate at an alarming rate.
Shoring up these resources, to ensure that they continue to thrive as valuable carbon sinks, is an increasing priority. And some action has already been taken.
In the lower mainland area of British Columbia, sediment is being added to existing marshes to raise their elevation, minimizing the impact of rising sea levels. We are also starting to see legislation passed in some coastal areas focused on protecting the existing seagrass and marsh areas.
But there is more work that is needed. Further legislation focused on not just protection, but restoration, is needed to regenerate these areas. An improved understanding of the numerous benefits of Canada’s blue carbon resources, and the value of investing in them, is also necessary to ensure that further damage does not occur. Without proper knowledge of the importance of blue carbon, development will continue to damage these precious resources.
There is much work still to be done. However, we can work together to protect Canada’s blue carbon resources, and work to restore them to their original prominence along Canada’s coastlines.
If you are a landowner, developer or municipality that is interested in learning more about how we can help protect our blue carbon resources, please visit: https://www.wsp.com/en-CA/services/biodiversity-conservation
Mel de Jager is WSP Canada’s Vice-President for Climate Change, Resilience and Sustainability. She can be reached at: Mel.DeJager@wsp.com
Patrick Lafrance is WSP Canada’s National Vice-President for Ecology and ESIA. He can be reached at: email@example.com