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 watching an upended boardwalk in Prince Edward Island Nationwide Park. Broken by the storm—one of many strongest cyclones ever recorded in Canada—Greenwich Seaside was nonetheless closed to most of the 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 achieve the sand dunes bordering the ocean. “The entire thing had been scarped,” he says, referring to how waves carried away massive quantities of sand from the seaward aspect, leaving the usually sloping face of the dune virtually vertical.
The injury 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 utterly worn out by a interval of storms 100 years in the past, and regenerated over many years,” he says.
Learn: The village that will probably be swept away
As local weather change interacts with storms, scientists are attempting to find out what occurs when dunes have much less time to recuperate.
Dunes are fashioned when wind deposits sand and shapes it into mounds. Greenwich Seaside has a roughly six-kilometer stretch of dunes; vegetation on high holds the sand in place. Throughout storms, rows of dunes act as boundaries, 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 might have been worse. The waves eroded the dunes, however the sand saved the storm surge from flooding in.
“Sand dunes are constructed to face up to 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.”
Thankfully, 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 recuperate will depend on the quantity of sand accessible to feed them. This isn’t a problem on Greenwich Seaside, the place sand is plentiful, however it could possibly current challenges in different areas. “You want a comparatively large seaside 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 are 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 larger and extra frequent hurricanes might transport a lot sand that dunes find yourself reforming in new locations.
But when we would like dunes to guard vital areas, corresponding to neighborhoods, there could also be some extent the place individuals must intervene to maintain the sand in place, van Proosdij says. In some locations, individuals are already shoring up weak dunes by trucking in seaside sand; reinforcing the mounds with bushes, 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 individuals can. “You possibly can’t beat nature,” he says. “You must 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, some of the vital dune-stabilizing crops, could be fatally trampled by as few as 10 footsteps. On Prince Edward Island, Parks Canada has blocked off notably delicate areas with rope and added signage to coach guests. “We would like dunes to be as resilient as doable earlier than a storm hits,” Paynter says.
Thankfully, the Greenwich Dunes have loads of area to shift and regrow with storms, as a result of the encompassing space is protected against improvement by the nationwide park. Exterior the park boundaries, Prince Edward Island just lately paused all coastal improvement whereas the province develops a long-term coverage to guard shoreline ecosystems.
It’s tough to foretell how lengthy it would take the Greenwich Dunes to achieve their former dimension, Ollerhead says. However at the same time as extra extreme hurricanes hammer Atlantic Canada, the forecast for dunes is mostly good—so long as individuals handle them. “A lot of the dunes will probably be effective,” he says. “We simply need to handle them in a approach that permits them to answer nature.”
