“Where we’re standing was open water,” boasted Bhaskar Subramanian on a sun-soaked and unseasonably warm morning last fall.
The Maryland Department of Natural Resources environmental scientist was standing on a sandy, crescent-shaped beach. Behind him, two small curved jetties, made of rock and covered in grasses, jutted into Chesapeake Bay.
Though it would have looked at home in a nature calendar, this slice of shore is actually a cutting-edge anti-erosion project. Scientists at the DNR’s Shoreline Conservation Service helped design it in the early 2000s, replacing a failing concrete bulkhead that had been protecting the Chesapeake Bay Environmental Center’s property. The jetties were carefully shaped to protect marsh grasses that the team had planted on a small replenished beach; workers from the center had also placed an oyster reef offshore to help break the motion of waves. This approach was notably more gradual than the concrete that had sharply separated the property’s lawn from the water.
Over the past decade, incoming waves calmed by the rocks and the oysters have deposited sand on the beach, and the marsh has expanded seaward, providing critical habitat for the young fish, crabs and terrapins that help filter the nutrient- and sediment-laden water washing off the land.
The project represents a small but growing countercurrent to a century-long buildup of shoreline defenses that relied on concrete and wooden bulkheads or piles of rock called revetments. Such structures, which have armored more than 1,000 miles of coastline in Maryland, can halt erosion temporarily by bouncing incoming waves back out to sea. But this protection carries a steep cost: Reflected wave energy destroys marshes and shallow-water vegetation, which are critical components of the wetlands that once supported huge quantities of crabs and fish and made the bay one of the world’s most biologically productive estuaries.
Government agencies looking for ways to increase resilience to storms and rising sea levels have begun to experiment with “living shorelines” such as the one at the center. In 2008, Maryland passed one of the nation’s first laws forbidding coastal property owners from installing a hard structure at water’s edge unless they can prove that a softer approach won’t work.
Last fall, the National Oceanic and Atmospheric Administration published its first document providing guidance on living shoreline construction techniques. It also suggests how to choose sites where such projects are likely to be effective, giving the practice a shot of credibility and national reach.
Subramanian, chief of the Shoreline Conservation Service, is among those leading the charge. His team of engineers and biologists designs experimental shorelines with as little rock and as many Spartina grasses and other wetland plants as possible, and sculpts them to deflect waves so they deposit sand rather than carry it away.
Early results are encouraging: Five experimental sites are gaining sediment. And the before-and-after surveys at two of the sites show that species including clams, shrimps and terrapins have increased since the living shorelines were put in.
But such innovative designs so far protect only a tiny fraction of Maryland’s more than 7,000 miles of coastline. Subramanian says that to reverse decades of ecological decline, scientists must come up with reliable design principles that can be replicated on a much larger scale while still being tailored to the varying conditions of individual sites.
“We have not figured it all out,” he said.
By most accounts, the living-shoreline concept was born in the mid-1970s when Edgar Garbisch, a chemist and heir to part of the Chrysler fortune, set out to show that it was possible to restore marshes. Near his family’s property on Maryland’s Eastern Shore, he placed a line of rocks in the water a few yards from shore, filled sand behind the rocks and planted marsh grasses in the sand. The experiment succeeded, and Garbisch’s project became a template for how to protect Chesapeake shorelines without concrete.
By the early 1980s, alarmed at how fast property owners were armoring their waterfronts with hard barriers, Maryland began giving grants and low-interest loans to encourage projects like Garbisch’s.
Addressing shoreline erosion is especially urgent for Maryland and other Mid-Atlantic states where land surface is sinking because of geological processes even as seas are rising because of climate change. As a result, Chesapeake Bay water levels are creeping upward at around twice the global average of 3 millimeters — about a tenth of an inch — per year. Some research indicates that natural and man-made marshes can build ground vertically fast enough to keep up with rising water — provided they receive sediment from waves or water coming off the land.
Dramatic proof that a living shoreline can forestall erosion and other damage came just weeks after the Chesapeake Bay center’s project was put in place. The DNR-led team had barely finished planting the marsh when Hurricane Isabel hit in 2003, flooding classrooms at the Naval Academy in Annapolis and properties in Baltimore’s Inner Harbor. The next day, the team found that an eight-foot storm surge had destroyed just about everything on the property — including a house — but the marsh grasses had mostly survived.
“We just couldn’t believe that it was really still intact to the degree that it was,” said Kevin Smith, who was DNR’s chief of wetland and river bank restoration at the time and who now works in the agency’s restoration, finance and policy division.
The experience helped convince both policymakers and property owners that living shorelines could be as effective as bulkheads. “We got a lot more projects done after 2003,” Subramanian said.
While many living shorelines are not only preventing erosion but also adding land, there have been setbacks. At a site on Kent Island in the middle of the bay, Subramanian and Smith built low rock-and-cobble breakwaters and planted sections of marsh to protect public parkland facing open water. Strong storms and winter ice knocked over many of the structures and ripped out some of the marsh grasses, whose young roots hadn’t taken hold.
“We went out on a limb,” Smith said. “And quite honestly we might have stepped a little too far out on that limb.”
But the site is not a complete failure, Smith and Subramanian say. Sand dunes have expanded, and the team has redesigned the shore protections to be more stable in storms. And they say they can apply the site’s lessons to future projects.
To better understand which practices reduce erosion and increase marsh habitat, Subramanian says he and his staff will survey several dozen other DNR sites and compare them against 2006 data on erosion, integrity of structures and marsh grass coverage.
Scientists are also starting to assess whether living shorelines promote life. Terrapin nesting sites have doubled at the Chesapeake Bay center since the living shoreline went in, and oysters on the artificial reef have increased, according to studies done by DNR scientists and colleagues.
Scientists have also found that at one living-shoreline site on the Chester River, populations of invertebrates such as worms, clams and shrimp are approaching those found in a natural marsh.
“That was very encouraging,” said Thomas Jordan, a Smithsonian Environmental Research Center ecologist who is leading that study.
Rochelle Seitz, a Virginia Institute of Marine Science ecologist who is involved in the Smithsonian study, sampled invertebrates in the sand before and after Subramanian worked on a site along the Corsica River in Queen Anne’s County. Within three years of the project’s completion, the combined weight of invertebrates Seitz collected had doubled.
Despite the promise of the living shoreline and the 2008 law, Maryland approves more than twice as many structural projects as living shorelines each year.
Because he cannot force people to build living shorelines, Subramanian takes skeptical property owners to see his projects in hopes of persuading them. “It’s a very slow process,” he said, but it can pay off. One property owner was resistant until Subramanian took him to Spaniard Point in Queen Anne’s County, where the DNR team had designed a pair of curving protective jetties that Subramanian calls the “crab claw.”
“We’d been working on him since 2007, and finally after he saw the Spaniard Point project in 2011, he said, ‘Yeah, I want that,’ ” Subramanian said.
“We’re trying to change people’s perceptions of what they can do with their shorelines,” Subramanian added. “What’s good for the bay doesn’t have to be exclusive of what people’s goals are [for] their properties.”
Correction: A previous version of the article incorrectly stated that Edward Garbisch’s wife was an heir to part of the Chrysler fortune. Garbisch’s mother was a member of the Chrysler family thereby making Garbisch an heir. This article has been updated.