EPA report shows potential damaging effects of sea level rise on Chesapeake Bay's marshes

A recently released report by the U.S. EPA shows that many areas around the Bay’s shoreline are already witnessing the effects of sea level rise and that vulnerable tidal marshes may erode more rapidly over the next century because of climate change.

The report, Coastal Sensitivity to Sea-Level Rise: A Focus on the Mid-Atlantic Region, examines the impacts of sea level rise on the human communities and wildlife habitat of the Mid-Atlantic coast, including Chesapeake Bay. According to the EPA, the Mid-Atlantic region is one area of the U.S. that will likely see the greatest impacts of climate change due to rising waters, coastal storms and a high population concentration along the coastline.

At the 20th century rate of sea level rise (3-4 mm per year), extensive areas of marsh in the Bay (depicted in red in the image to the right) will become marginal, or only able to survive under optimal conditions. Other low-lying areas, depicted in blue, will be fully submerged at the current rate of sea level rise. The report cites evidence that sea level rise is increasing due to climate change, which would accelerate erosion of the Bay’s marshes.

A clear example of the effects of sea level rise can be seen on the Bay’s marsh islands, many of which have already been lost or severely eroded. These islands are vital to bird species like terns, black skimmers and American oystercatchers, which use the islands to nest and breed. On the mainland shoreline of the Bay, nearly all of the beaches are eroding, which has led many waterfront property owners to install hardened shorelines as protection.

In addition to the effects of sea level rise, the report details the efforts of state and local governments throughout the Mid-Atlantic to protect coastal communities against erosion. Maryland is noted as having the most stringent policies on development along the Chesapeake and coastal areas. The state’s Critical Area laws limit development within 1,000 feet of the shoreline.

“Our state is particularly vulnerable to the impacts of climate change -- including sea level rise,” said Maryland Gov. Martin O’Malley in response to the EPA report. “We are making real progress in both preparing for the impacts of climate change but also in reducing the actions that contribute to it.”

However, the report shows that most shoreline protection structures are designed to protect properties from current sea level, rather than the anticipated increases. “Preparing now can reduce the eventual environmental and economic impacts of sea level rise,” reads a report highlight.

Waterfront property owners interested in learning more on how they can protect their shoreline from erosion and sea level rise can visit Maryland DNR’s website for more information.