P.E.I. dunes are recovering post-Fiona, but winter could be challenging

Post-tropical storm Fiona brought sudden and dramatic change to P.E.I.'s North Shore last September, but researchers are already seeing some significant recovery.

"Dunes are very dynamic," said Chris Houser, dean of science at the University of Waterloo and a professor in its Department of Earth and Environmental Sciences.

"We really don't have a good understanding about dune recovery. A lot of work has been done on the actual storm impact and the amount of erosion, because it's impressive, it's in a moment. Recovery takes years."

While it was understood a year ago that recovery would be slow, some signs are emerging that it is starting already.

The waves and storm surge from Fiona carved as much as 10 metres of dune away in a single night. Where there had been slopes covered with marram grass, a sharp-edged sand cliff was left behind.

But those cliffs were unstable. Their top edges began to collapse onto the beach below. At the same time, sand that had been washed away began to be pushed back on shore by the waves and tide. Once on dry land, the sand was blown back up against the cliff, contributing to the re-creation of the previous slope.

More than that was needed, however. The dunes had to have something to hold them together.

"We want the vegetation, not only to hold the sediment in place but also to catch sand that's blowing up the beach," said P.E.I. National Park ecologist Hailey Paynter.

"That's where we'll really see the dunes rebuilding. First step is having some of that vegetation re-establish."

Marram grass is the best known of these ocean-side dune plants, but the ecosystem also includes beach pea, sea rocket, and blue-green artemisia, also known as hoary mugwort.

A big part of the establishment of these essential plants is keeping people out of the areas where dunes are regrowing, because one ill-placed foot can disturb the growth of a young plant.

Education about the importance of staying off the dunes has always been part of P.E.I. National Park's work, but it has taken on a special emphasis on Prince Edward Island over the last year.

"Allowing these dunes the space and time to recover without people trampling on them — that's the best thing we can do," said Paynter.

Visitors have been heeding the warnings, she said.