Many scientists have debated whether coastal wetlands can survive sea-level rise by migrating inland. A new analysis by the Virginia Institute of Marine Science using highly detailed elevation maps of the Chesapeake Bay region shows that—contrary to previous studies—human barriers will do little to slow this marsh migration.

Instead, extensive areas of low-lying rural land will allow coastal marshes to persist or even expand as salty water creeps upward into what are now forests and farmland.

“The numbers are striking,” said lead author Grace Molino, a Ph.D. student at VIMS. “Bay-wide, we expect more than 600 square miles of inundated land in the Chesapeake region by 2100.”

That is four times the area that has converted to marshland in the Chesapeake Bay region since historical observations began in the 1840s, and more than 75 percent will be rural (mainly forests, forested wetlands and farm fields).

Joining Molino on the study, which appears in the latest issue of “Limnol...