after hurricane sandy hit new york city in 2012, parts of the city were inundated. more than 40 people died, millions of new yorkers were without power, and hundreds of homes were destroyed. 

joe christo, who helped lead the city’s recovery efforts, said the storm was a wake-up call to the dangers of sea level rise. the hurricane cost the city $19 billion in damages, according to a report by the new york city comptroller. 

christo now works as managing director of the stone living lab, a boston-based partnership between the university of massachusetts boston’s school of the environment, boston harbor now, the city of boston, and other state and local environmental groups.

“a sandy-like storm will hit here,” christo said about boston. “and we want to try to be as prepared and ready as possible.” coastal communities are most at risk when sea level rise combines with high tides and a severe storm like sandy — the triple threat that slammed manhattan. 

to the north, about one-sixth of boston sits on landfill, making it particularly vulnerable to sea level rise. this vulnerability is made worse by sea levels rising faster — scientists predict about 1 inch every eight years. at this rate, by 2050 boston could see over a foot of sea level rise compared to 2016.

as part of the climate ready boston initiative, the city developed coastal resilience plans for all 47 miles of its coastline. the plans include developing coastal parks, raising harbor walks, building seawalls, and adapting waterfront buildings, with a focus on completing projects in high flood-risk areas by 2030.

the stone living lab’s goal is to scale up nature-based approaches as a defense against sea level rise. 

“a traditional vertical seawall works against water, and nature-based approaches work with water,” christo said. “water’s always going to win, so you want to be working with it and be able to absorb and adapt instead of trying to fight against it.”

nature-based approaches include restoring salt marshes, building oyster reefs, protecting sand dunes, and building coastal parks. christo said these approaches protect the shorelines and also bring co-benefits, like increasing biodiversity and sequestering carbon. 

most recently, the lab has been testing out a living seawall and an erosion prevention project. the hope is that these projects can provide compelling evidence for the benefits of nature-based approaches so that they can become more mainstream. 

“we want these lessons to be applied to other coastal areas throughout north america and throughout the world,” christo said. 

the stone living lab’s nature-inspired seawall

in east boston’s harbor, a handful of snails, two mussels, and species of algae are nestled into the crevices and divots across the surface of concrete panels installed on a vertical seawall. 

the species are able to call this spot their new home thanks to the living seawalls pilot project, a nature-based solution spearheaded by the stone living lab that turns traditional seawalls, usually devoid of life, into a space for marine biodiversity. in october, panels were installed at two existing seawalls in east boston and the seaport. 

the 40-pound, 2-by-2-foot panels were 3d printed to mimic natural habitats along the shoreline. they were installed along the intertidal line of the seawalls to be submerged at high tide and exposed at low. the whole project cost $400,000, according to christo.

the panels are regularly monitored by a group from project partner umass boston for changes in marine life, with portions of the seawall left without panels to serve as a comparison. 

jarrett byrnes, the project lead and associate professor at umass boston, said seawalls are an inevitable part of combating sea level rise, especially in urban areas where space is limited. but a slab of concrete or stacks of granite blocks is not ideal for marine biodiversity. 

“what we are trying to do with the living seawall project is create a habitat for native biodiversity to survive and thrive,” he said. “we’re trying to turn what is a win-lose into a win-win.”

the panels provide a rocky intertidal habitat — places with shade and moisture where species like mussels, crabs, and algae can thrive.

although it’s the seawall structure that protects against rising waters, byrnes said it’s possible that species growth on the panels could dampen wave action, a potential added benefit. 

byrnes is excited to know what the surface of the living seawalls will look like in a year. he predicts that because each panel is uniquely textured, different species will thrive on certain panels. 

“as we continue to armor our shorelines, i’m hoping that this is going to be one arrow in our quiver of making sure that coastal armoring doesn’t mean reducing nature,” he said. 

installing cobble berms across massachusetts’ coast

a strip of cobblestones along the coastline may look unassuming in massachusetts, where rocky shorelines are common. but these strips of 3- to 10-inch sized rocks, otherwise known as cobble berms, protect against sea level rise and storm surge. 

cobble berms are often naturally occurring on rocky coastlines. stones are pushed toward the back of the beach by waves, forming a berm, or a flat strip of raised land. the berms absorb wave energy and protect coastal banks and dunes from erosion. 

seawalls often have waves crashing over them and can cause erosion to the beach in front of them. cobble berms act differently. 

“if you think about a cushion, the cobble berms will move and act as a cushion to some of that wave energy, as opposed to say, a concrete seawall,” said kirk bosma, a senior coastal engineer at the woods hole group. 

the stone living lab, in partnership with the woods hole group and massachusetts office of coastal zone management, recently launched a cobble berms monitoring project. several man-made berms and enhancements to natural ones were installed at six sites across massachusetts, including one in boston. 

over the past two years, research staff partnered with the stone living lab have regularly surveyed the berms. 

data is still being gathered, but from preliminary findings, bosma said that in all six locations, erosion was reduced in areas behind the cobble berms. the data also showed an increase in species richness between cobbles and near the cobble berms, and further analysis is underway. 

“there is some added benefit beyond what they are able to do from a resiliency perspective,” bosma said. 

bosma hopes to install a pilot cobble berm in boston for an in-depth study. he envisions testing out different designs with varying shapes and sizes of cobbles, as well as tagging the cobbles to see how they move over time. 

“we’re learning … what mother nature wants to do to provide resilience,” bosma said.