Beyond the storm: science for managing our changing coast
There is a silver lining to every storm cloud, and to many coastal sites in the North Atlantic region, too.
Consider Blackwater National Wildlife Refuge on the eastern shore of the Chesapeake Bay in Maryland, established as a sanctuary for migratory birds because of the vast expanse of contiguous saltmarsh habitat encompassed within. A study conducted by Salisbury University revealed that between 1938 and 2006, the Refuge lost over 5,000 acres of that marsh to land subsidence, erosion, and sea-level rise. That’s equivalent to more than a third of Manhattan.
“It hasn’t gotten any better since then,” notes Matt Whitbeck, Supervisory Wildlife Biologist at Chesapeake Marshlands National Wildlife Complex, which includes Blackwater. For the communities of people and wildlife that rely on those tidal wetlands for food, shelter, and quality of life, the forecast probably looks pretty gloomy.
But hark, is that a bright spot on the horizon? “That study also shows that as sea levels rose, nearly 3,000 acres of upland at Blackwater converted to new tidal marsh,” explains Whitbeck.
That’s because Blackwater has both the physical space and functional processes, like inputs of sediment and freshwater, needed for marsh habitat to migrate inland. And it’s not the only bright spot. In a new study supported by Hurricane Sandy Resilience Funding, scientists from The Nature Conservancy (TNC) identified thousands of other coastal sites that have the potential to migrate, and in doing so, to offset more than 50 percent of the total predicted tidal habitat loss in the region.
TNC calls these places “coastal strongholds.” I call them silver linings.
The final product is called Identifying Resilient Coastal Sites for Conservation, and offers a resource for managers working at any scale to make strategic decisions toward helping coastal systems and communities adapt to changing conditions. The report and data are available to download from TNC’s Conservation Gateway, and will soon be rolled into the Nature’s Network conservation design to refine existing information on opportunities to maintain regional connections and connect tidal marshes to adjacent uplands.
“Because of the rate of change we are seeing in the Chesapeake Bay — where sea level rise is twice the global average — we need to think not only about where habitats are now, but where they are going in the future,” explains Whitbeck.
To his credit, he has been thinking about that for years. In 2011, Whitbeck partnered with The Conservation Fund, Audubon Maryland – DC, and the Chesapeake Conservancy to develop a strategy for salt marsh persistence at Blackwater.
But he says TNC’s tool represents a “huge step” forward. “It reinforces what we found in our study, but it also expands upon it, and can help us work across borders with new partners.”
A collaborative approach is critical for Refuges to meet their mandates for protecting fish and wildlife, and for ensuring that neighboring communities continue to benefit from functioning natural systems. Blackwater provides habitat for at-risk species like saltmarsh sparrow and Delmarva fox squirrel, and a nursery for species like blue crab that support the Chesapeake Bay’s economically and culturally important fishing industry.
The Refuge also provides a buffer against destructive storm surges that threaten infrastructure and public safety. TNC’s study is a call to action for protecting the marsh habitat we depend upon, but it also offers strategic guidance for how to do so effectively and efficiently.
“Although the study confirms that the Chesapeake Bay is seeing a great deal of marsh loss, it also shows that this system can be resilient moving forward if we plan right,” says Whitbeck.
And nowadays, planning “right” requires planning for change.
“When I was in school, pre-colonial conditions were the gold standard for land management. What was it like a few hundred years ago? That’s what we want to bring it back to,” remembers Whitbeck. “The lesson at Blackwater is that we have to let that go and think dynamically about maintaining a suite of habitats and ecosystem services across an entire landscape, and this tool can help us do that.”
The new gold standard might be to look for the silver lining.