‘Living Shorelines’ Will Get Fast Track to Combat Sea Level Rise
Scientific American - 07/06/2016
As sea levels rise along U.S. coasts, it may soon get easier for people and local governments to obtain federal permits to build what are known as “living shorelines,” natural or nature-based structures designed to protect communities and infrastructure from extreme storms and flooding even as they protect habitat.
The Army Corps of Engineers is considering a new category to its nationwide permits that would allow speedier approval of living shorelines, which include wetlands with sea and marsh grasses, sand dunes, mangroves, and coral reefs.
Studies have shown that living shorelines host greater populations of fish and other organisms crucial for shorebirds and for recreation and commercial fisheries, said Rachel Gittman, a postdoctoral research associate at Northeastern University’s Marine Science Center. Gittman, who spends much of her time in North Carolina, was asked by the Pew Charitable Trusts to analyze the effectiveness of natural shorelines compared to hard infrastructure. The work is part of the foundation’s climate adaptation efforts to improve flood readiness in U.S. communities.
Bulkheads, sea walls and vertical structures with marginal structural complexity don’t provide the same habitat for marine organisms as natural shorelines, Gittman said.
“It’s not the same type of habitat. It’s a difference in the slope of the shoreline. A vertical wall is very different than the slope of the shoreline. We think it has to do with the wave dynamic, so how sediment is transported changes when you put in a wall,” she said. “And we also just think it’s a simplification of that shoreline. So you go from a shoreline that might have lots of pools and crevices and rocks … to a wall. Organisms are not finding refuge along that shoreline.”