Marshes lying at or below the water line on the southwestern corner of the Eastern Shore might be swallowed up by the Bay by the end of the 2020s, according to the lead author of a study of how sea level rise will affect the northern half of eastern seaboard.
The chances are no better than even that those marshes can adapt fast enough to survive encroaching waters after the next decade, said U.S. Geological Survey scientist Erika Lentz. Lentz and her colleagues found that marshes, forests and especially beaches will adapt to sea level rise, to varying degrees. The study, published in the journal Nature Climate Change, offered relatively promising news for undeveloped parts of the coast as a whole.
“The shore might look at lot different but it will still be there,” Lentz told the Bay Journal.
However, the study found that marshes at or below the water line are unlikely to move inland fast enough to avoid inundation by rising sea levels predicted beyond the 2020s. The only portion of Bay captured in the study’s satellite images was along the southwestern edge of the Eastern Shore.
Doug Myers, senior scientist with the Chesapeake Bay Foundation, said marshes will move inland as long as they don’t run up against a barrier, such as a road. Steps can taken to preserve them, he said, such as removing barriers and spraying modest amounts of sediment on them to keep them from being inundated.
The Bay Foundation is working with Wicomico County, MD. and the Army Corps of Engineers to build up local marshes there, using sediment dredged periodically from the Wicomico River for navigation purposes, Myers said.
Donald Boesch, president of the University of Maryland Center for Environmental Science, pointed out that there are a number of studies looking at the survivability of marshes in the midst of sea level rise, and the findings vary.
“It’s hard to predict the rate and pattern of marsh erosion,” he noted, adding that a recent study from the Virginia Institute of Marine Science found that the marshes would fare somewhat better.
“We need to know where we can take action to protect marshes, allow them to move inland and add sediment,“ he said.
In the meantime, the threats posed by unchecked greenhouse gas emissions are severe, Boesch warned.
“We could see a Bay that’s a lot bigger, a lot deeper, with just a few marshes – or not,” Boesch said.
“It all depends on the choices made by this generation and the next,” Boesch said. If nothing changes soon, he said, all indications are that there will be vast sea level rise in the 2100s, with the Antarctic ice shelf disintegrating and melting.
This story was revised and updated on March 30