Value Between the Tidelines: PEI Salt Marshes Hold Carbon Worth $580 Million

26 Oct Value Between the Tidelines: PEI Salt Marshes Hold Carbon Worth $580 Million

Posted at 16:54h in News by

Value Between the Tidelines: PEI Salt Marshes Hold Carbon Worth $580 Million

CHARLOTTETOWN, PEI – Walk along the edge of a Prince Edward Island salt marsh at low tide, and you’ll see grasses, mudflats, and shorebirds foraging in the shallows. What you can’t see is what lies beneath your feet: a vast store of carbon locked in the soil.

New research highlights just how significant this carbon storage is. Salt marsh soils across Prince Edward Island store an average of approximately 68 tonnes of carbon per hectare (about 60,000 pounds per acre), based on measurements collected at study sites throughout the province.

“People often think of marshes as quiet, empty places,” says Heather Laiskonis, Executive Director of the PEI Watershed Alliance. “But these soils are working hard every day. They are holding carbon that would otherwise warm our planet.”

Adding It All Up

The Government of Prince Edward Island has identified approximately 7,612 hectares of salt and brackish marshes across the province. While this inventory does not capture every marshland, applying the research findings to these identified areas reveals the significant carbon storage potential of PEI’s coastal wetlands.

Researchers estimate that PEI’s salt marsh soils collectively store more than 500,000 tonnes of carbon, with a reported social value of approximately $580 million.

What Does Social Value Mean?

The estimated dollar value is based on the social cost of carbon, an economic measure used to estimate the societal damages associated with additional greenhouse gas emissions.

These damages can include impacts on human health, agriculture, fisheries, infrastructure, and natural ecosystems.

For this study, researchers used a social cost estimate of $1,128 per tonne of carbon dioxide (CO₂) to assess the value associated with carbon stored in PEI’s salt marsh soils.

Importantly, this figure does not represent the market price of PEI’s wetlands or potential revenue from carbon credits. Rather, it illustrates the potential economic consequences associated with releasing stored carbon into the atmosphere.

“This number helps us see what’s at stake,” says Laiskonis. “It tells us what we could lose if these places disappear. And it shows Islanders the numbers behind something they already know; protecting nature is a worthy investment in our future.”

More Than Carbon: The Many Benefits of Salt Marshes

Carbon storage is only one of the many important services provided by healthy salt marshes.

These coastal ecosystems also:

  • Help protect coastal communities from flooding and storm surges.
  • Provide essential habitat for fish, birds, and other wildlife.
  • Improve water quality by filtering pollutants and trapping sediments.
  • Support coastal resilience in the face of climate change.
  • Contribute to the natural beauty and ecological health of PEI’s coastlines.

These benefits, known as ecosystem services, carry significant environmental, social, and economic value beyond carbon storage.

When marshes are drained, filled, or otherwise damaged, some of their stored carbon can be released into the atmosphere. At the same time, communities may lose natural protection against flooding, erosion, and severe weather.

Replacing these services through engineered infrastructure can be expensive and, in some cases, impossible.

Despite their importance, the full value of wetlands is often overlooked in land-use planning and development decisions.

A Climate Solution We Already Have

As researchers around the world explore new technologies to remove carbon dioxide from the atmosphere, PEI already has an important natural climate solution along its shores: protecting and restoring existing wetlands.

“We don’t need to invent anything new,” says Laiskonis. “The solution is already here, growing along our shores. If we protect our wetlands, they keep doing their job for us.”

Healthy salt marshes also support biodiversity, provide habitat for wildlife, and contribute to the scenic coastal landscapes that are central to PEI’s identity and tourism industry.

The findings reinforce the importance of recognizing salt marshes and wetlands as valuable natural infrastructure that should be considered in decisions related to coastal development, wetland conservation, and climate adaptation.

“Protecting our salt marshes isn’t only about the environment,” says Laiskonis. “It’s an investment in PEI’s long-term economy and in our ability to bounce back from a changing climate.”

About the PEI Watershed Alliance

The PEI Watershed Alliance represents 25 community-based watershed organizations working to protect, restore, and enhance watersheds across Prince Edward Island.

Through restoration projects, environmental monitoring, education, and advocacy, the Alliance supports healthy watersheds, thriving ecosystems, and resilient Island communities.

Research Acknowledgements

This research was made possible through funding from the Government of Canada’s Nature Smart Climate Solutions Fund, supporting the PEI Watershed Alliance and participating member organizations in their efforts to better understand, enhance, and protect PEI’s salt marshes and wetlands.

The project contributes to a growing understanding of the important role these coastal ecosystems play in carbon storage and climate resilience.

Special thanks to the team at TransCoastal Adaptations at Saint Mary’s University for conducting the field sampling and laboratory work throughout this project.