This text initially appeared in Hakai Journal.
Two weeks after Hurricane Fiona made landfall in Atlantic Canada on September 24, 2022, Jeff Ollerhead discovered himself gazing an upended boardwalk in Prince Edward Island Nationwide Park. Broken by the storm—one of many strongest cyclones ever recorded in Canada—Greenwich Seashore was nonetheless closed to most people. Ollerhead, who’s a coastal geomorphologist at Mount Allison College, in New Brunswick, treads rigorously across the doomed boardwalk and a big pond to succeed in the sand dunes bordering the ocean. “The entire thing had been scarped,” he says, referring to how waves carried away giant quantities of sand from the seaward aspect, leaving the usually sloping face of the dune virtually vertical.
The harm Ollerhead witnessed final fall was dramatic however not surprising. The scientist, who monitored the Greenwich Dunes for twenty years till 2015, is aware of that the dunes have confronted comparable devastation prior to now. “Greenwich was fully worn out by a interval of storms 100 years in the past, and regenerated over a long time,” he says.
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As local weather change interacts with storms, scientists try to find out what occurs when dunes have much less time to get well.
Dunes are shaped when wind deposits sand and shapes it into mounds. Greenwich Seashore has a roughly six-kilometer stretch of dunes; vegetation on high holds the sand in place. Throughout storms, rows of dunes act as limitations, defending inland areas. Just a few of Hurricane Fiona’s excessive waves topped the crest of the Greenwich Dunes—although if the storm had hit throughout excessive tide, it may have been worse. The waves eroded the dunes, however the sand saved the storm surge from flooding in.
“Sand dunes are constructed to resist storms,” says Hailey Paynter, an ecologist with Parks Canada, the federal company that manages the nationwide park. “They merely want time and area to regrow.”
Happily, within the 12 months since Hurricane Fiona, the Greenwich Dunes have proven indicators of restoration. Vegetation are popping up on the ridges closest to the ocean. Over the subsequent few years, the dunes will slowly develop as blowing sand collects across the vegetation.
How rapidly dunes get well is determined by the quantity of sand obtainable to feed them. This isn’t a difficulty on Greenwich Seashore, the place sand is plentiful, however it may current challenges in different areas. “You want a comparatively huge seashore and dry sand,” says Danika van Proosdij, a coastal geomorphologist at Saint Mary’s College, in Nova Scotia. Dunes on narrower seashores or seashores which might be typically submerged by the tide will take longer to rebuild.
Over time, winds naturally shift the place of sand dunes, and, van Proosdij says, main storms can regularly transfer dunes inland by pushing sand from the ocean-facing aspect excessive like a conveyor belt. Repeated erosion from greater and extra frequent hurricanes may transport a lot sand that dunes find yourself reforming in new locations.
But when we wish dunes to guard vital areas, resembling neighborhoods, there could also be a degree the place folks have to intervene to maintain the sand in place, van Proosdij says. In some locations, individuals are already shoring up weak dunes by trucking in seashore sand; reinforcing the mounds with timber, logs, and different biodegradable supplies that decelerate the motion of sand; or planting vegetation on high.
Ollerhead factors out that pure restoration could also be gradual, however nature can engineer dunes higher than folks can. “You possibly can’t beat nature,” he says. “You need to be taught to work with it.” The general public can do its half by leaving dunes alone. Regardless of the resilience of dunes throughout storms, they’re fragile: Marram grass, one of the vital dune-stabilizing vegetation, may be fatally trampled by as few as 10 footsteps. On Prince Edward Island, Parks Canada has blocked off significantly delicate areas with rope and added signage to coach guests. “We would like dunes to be as resilient as potential earlier than a storm hits,” Paynter says.
Happily, the Greenwich Dunes have loads of area to shift and regrow with storms, as a result of the encircling space is protected against growth by the nationwide park. Outdoors the park boundaries, Prince Edward Island not too long ago paused all coastal growth whereas the province develops a long-term coverage to guard shoreline ecosystems.
It’s troublesome to foretell how lengthy it would take the Greenwich Dunes to succeed in their former measurement, Ollerhead says. However whilst extra extreme hurricanes hammer Atlantic Canada, the forecast for dunes is mostly good—so long as folks deal with them. “A lot of the dunes might be superb,” he says. “We simply must handle them in a manner that enables them to answer nature.”
