• Volunteers with the Nature Conservancy of Canada plant marram grass on the dunes near St. Peters Harbour on May 29, 2016. Marram grass grows extensive root systems that help preserve the integrity of the dunes, an important buffer against erosion. (Photo: Sean Landsman)

On the last weekend in May, a group of around 20 Prince Edward Islanders gathered at St. Peters Harbour on the Gulf of St. Lawrence to shore up their province's defences against erosion — by planting grass.

Marram grass grows extensive root systems in loose sand, making it an important component of a healthy dune ecosystem that supports endangered seabirds such as the piping plover. But it also provides a natural buffer against the wind and waves that carve away a little more of the island's north shore every year — a natural process of erosion that climate change is accelerating.

"From a conservation perspective, sand dunes were always valuable habitats, but these places are increasingly critical in terms of how we can adapt to climate change," says Dan Kraus, Weston Conservation Scientist with the Nature Conservancy of Canada (NCC), which organized the marram grass planting.

All of Canada's coastal areas are threatened by climate change-related sea level rise, but perhaps none so drastically as Prince Edward Island, which is low, flat and composed of soft sandstone, making it particularly vulnerable to erosion. Researchers from the University of Prince Edward Island estimate that the ocean will encroach upon some 1,000 homes and buildings, 45 kilometres of road and five sewage treatment facilities within the next 90 years.

While healthy marram grass dunes won't stop coastal erosion, they do provide a buffer against storm surges that can easily wipe out unprotected harbours and cause massive damage to property.

"Beaches are dynamic, volatile systems that are going to change no matter what," explains Julie Vasseur, program director for the NCC in P.E.I. "But if you lose the grass and you lose the dunes, everything behind the beach is exposed to the weather conditions the dunes were helping to absorb."

Adds Kraus, "We need to start thinking of these sensitive habitats as a kind of infrastructure."

The public has an important role to play in protecting marram grass dunes, namely by staying out of them: in addition to planting new grass, the St. Peters Harbour volunteers also built a boardwalk so people can admire the dunes and access the beach without trampling the fragile plants.

Related: Nature Conservancy of Canada protects P.E.I. 'hotel for birds'