Owning and maintaining waterfront property can be an expensive commitment. Residents across the Chesapeake Bay watershed must contend with shoreline erosion and rising sea level, while adapting to environmental regulations that protect water quality. One strategy for tackling all of these issues has gained increasing popularity: living shorelines that not only protect human property, but also utilize and even enhance the Bay’s unique natural habitat.
Scott Hardaway and Karen Duhring are marine scientists and living shoreline experts at the Virginia Institute of Marine Science (VIMS), which sits at the mouth of the York River in Gloucester Point, Va.
Scott Hardaway began working for VIMS in 1979, and is now the director of the Shoreline Studies Program. He is a leading authority on the design and implementation of “headland breakwaters,” a living shoreline technique that creates protected “pocket beaches” like those constructed at VIMS in 2010.
Headland breakwater systems are built using large stone structures called “headlands,” which sit offshore and disrupt the incoming waves that can cause shoreline erosion. Mathematical formulas determine the necessary angle, shape and placement of each headland. Wider gaps between breakwaters create long, narrow pocket beaches, while narrow gaps create wide, circular beaches.
Their wave-blocking action creates a calm, shallow lagoon between the breakwaters, which are connected to shore by a sandbar called a “tombolo.”
Additional sand must be brought in to form the tombolo and stabilize the beach. This raises the cost of these projects, but is critical to the final phase of construction: planting native beach and dune vegetation.
Karen Duhring is an educator and researcher at the VIMS Center for Coastal Resources Management (CCRM), where she helps manage and monitor living shoreline projects.
According to Duhring, on-shore plantings serve key ecological functions that enhance the effectiveness of living shorelines. On sandy beaches, plant roots stabilize loose material and improve water quality, as they filter pollutants from upland runoff.
Living shorelines use native plants—smooth and saltmeadow cordgrass here in the Bay—that have adapted to thrive and reproduce in a specific environment. Once established, cordgrass recruits naturally along the beach, dispersing seeds and rhizomes that spread horizontally beneath the sand to establish new plants in empty areas.
Beach plantings are susceptible to damage from foot traffic, so precautions should be taken to prevent the trampling of plants. Access restrictions allowed for more expensive plantings on the VIMS western shore, while heavy use from research activities limited plantings on the other.
During high tides, organic material washes onto the beach and provides nutrients for the growing plants, which in turn provide habitat and food for native wildlife.
Headland breakwaters themselves also provide habitat for crabs, mollusks and other aquatic species that thrive on underwater reefs. Along the VIMS shoreline, oysters have settled on the granite rocks to form the beginnings of a complex reef community.
According to Hardaway, headland breakwaters are not always the perfect solution for every sandy shoreline. Whenever possible, existing habitat for submerged aquatic vegetation and shellfish should remain undisturbed. While the costly structures do come with some tradeoffs, they also offer invaluable protection for human infrastructure. The once-vulnerable VIMS shoreline, for instance, has withstood Hurricanes Irene and Sandy—thanks to its headland breakwaters.
As the living shorelines at VIMS demonstrate, projects such as these—which successfully address the needs of both humans and nature—are critical to Bay restoration. Through the work of experts like Hardaway and Duhring, these living shorelines continue to serve both practical and educational purposes, teaching the public how we can responsibly manage our natural resources today in order to preserve them long into the future.
View full-resolution photos on the Chesapeake Bay Program Flickr page.
Thanksgiving is the perfect time to express gratitude for the good in life. We have much to be thankful for—and so does the Chesapeake Bay! Here is a look at six moments from the past year that signaled good news for the watershed.
6. A sustainable blue crab population. The most recent report on the Bay’s blue crab stock reveals a population that has reached sustainable levels and is not overfished. Winter estimates place the adult female blue crab population at 97 million, based on a dredge survey taken at almost 1,500 sites throughout the Bay. The survey also measured more juveniles than have been counted in the past two decades. A stable blue crab population means a more stable Bay economy, with watermen employed, restaurants stocked and recreational crabbers (and crab-eaters!) happy.
Image courtesy Erickson Smith/Flickr
5. Additional American eels. American eel numbers are up in the headwater streams of Shenandoah National Park, following the removal of a large dam that once blocked eels from moving upstream. Other anadromous swimmers like shad, herring and striped bass—which must migrate from the ocean into rivers to spawn—are also using this reopened habitat. Our rivers are thankful to see the return of these important residents.
4. A huge boost in oyster restoration. This year, restoration partners in Maryland put more than 600 million oyster spat into the Chesapeake Bay in the largest targeted restoration effort the watershed has ever seen. While some of the oyster larvae went into the Upper Bay, most went into Harris Creek, a tributary of the Choptank River that was declared an oyster sanctuary in 2010. While habitat loss, disease and historic overfishing have contributed to a dramatic decline in native oyster populations, planting “spat on shell” onto harvest-safe sanctuaries is one way to bring the water-filtering bivalves back.
3. A lot of living shorelines. When shorelines wash away, fish, crabs and other wildlife lose valuable habitat, and coastal landowners lose their lawns. To curb shoreline erosion, coastal property owners are turning toward living shorelines, which replace hardened bulkhead and riprap with grasses and trees. This summer, the Chesapeake Bay Trust’s Living Shorelines program awarded $800,000 to 16 homeowner associations, non-profit organizations and towns to install more than 6,800 feet of living shoreline and wetland habitat in the Chesapeake Bay watershed.
2. Greater green infrastructure. With the implementation of green infrastructure, cities can use the natural environment to better manage stormwater runoff. Green roofs, rain gardens and pervious pavement, for instance, can absorb stormwater runoff before it flows into local rivers and streams. This year, the U.S. Environmental Protection Agency (EPA) and the National Fish and Wildlife Foundation (NFWF) awarded $4 million to local governments for green infrastructure projects. But the environment is not the only one who will be thankful; green infrastructure can revitalize communities and produce cost benefits that can exceed those of traditional stormwater management methods. We are grateful that more towns will be greener in both color and concept!
1. Long-term improvements in Bay health. A number of Bay monitoring sites have shown long-term improvements in nutrient and sediment levels. According to an August report from the U.S. Geological Survey (USGS), one-third of monitoring sites have shown improvement in sediment concentrations since 1985, two-thirds have shown improvement in nitrogen concentrations and almost all have shown improvement in phosphorous concentrations. These improvements in long-term trends indicate pollution-reduction efforts—from upgrades to wastewater treatment plants to cuts in fertilizer use on farms and suburban lawns—are working.
More than 6,800 feet of living shoreline will be coming to the Chesapeake Bay, thanks to $800,000 in federal, state and private funding announced this week.
Living shorelines provide coastal landowners with an erosion-control alternative, as grasses and trees replace hardened bulkhead and riprap to stabilize the shoreline and provide vital habitat to fish, crabs and other wildlife.
Sixteen homeowner associations, non-profit organizations and towns will receive funding through the Chesapeake Bay Trust's Living Shorelines program, a multi-state effort that promotes the installation and understanding of living shorelines throughout the watershed.
The Chester River Association, for instance, will restore 270 feet of shoreline in Centreville, Md., protecting a wetland and creating an outdoor classroom for children and adults. The Northern Virginia Regional Commission will design a 542-foot shoreline in a Woodbridge, Va., public park along the Potomac River. And Alice Murray and Susan Stricker will restore 410 feet of shoreline on their eroding Popham Creek property, thanks to an almost $40,000 grant administered to the West/Rhode Riverkeeper.
The non-profit organization, which advocates for the West and Rhode rivers as part of the Riverkeeper Alliance, will provide the mother-daughter pair with guidance throughout the project, which will be furthered by a significant cash match from a Maryland Department of Natural Resources loan.
"I have been wanting to do this for 50 years," Murray said. "It's a thrill!"
While Murray and Stricker often see shorebirds, waterfowl and even fox near their beach, both hope the new shoreline will bring more wildlife to the area and help restore the creek that seems to be missing the underwater grasses, plentiful fish and clear water of the past.
Now in its seventh year, the Living Shorelines program has awarded more than $4 million to 68 Maryland and Virginia projects, creating 28,000 feet of living shoreline and 18 acres of wetland habitat. This year marks the largest amount ever awarded to support this restoration technique.