Can Mud Save the Chesapeake Bay?

Salt Marsh Sparrow

No, but mud and $13 million can possibly help an endangered sparrow. Bay Journal, Officials spray mud onto Chesapeake island to save imperiled saltmarsh sparrows. 

About a decade ago, a bird species facing a rapid population decline vanished from one of its previously documented haunts on Maryland’s Eastern Shore. What had once been a swath of ideal high-marsh habitat for saltmarsh sparrows near Deal Island now flooded too often.

Experts cite sea level rise as one of the main drivers of the increased flooding, which in turn accelerates erosion and, ultimately, the loss of the marshes.

Saltmarsh sparrows build their nests close to the ground amid wetland grasses. With high tides and storm surges inundating those nests more often, the birds fled, said David Curson, director of bird conservation for Audubon Mid-Atlantic.

“If we don’t take action, nearly all of the marshes in the [Chesapeake] Bay will be lost to erosion by the end of this century,” said Curson, who has surveyed the Deal Island population for years. “This would be a real disaster because of the essential ecosystem services they provide.”

Actually, marshes will move backward, up the slope as seawater advances, if they are given room to grow. 

After four years of planning, a $13 million effort is underway to test a possible solution. The U.S. Army Corps of Engineers is using mud dredged from a nearby river to raise the height of a section of marshland that once hosted the sparrows.

A dredge operated by Cottrell Contracting Corp. of Chesapeake, VA, started siphoning muck from the bottom of the lower Wicomico River in mid-October. That is routine. Since the 1890s, the river has been dredged every few years to maintain adequate depth for ships traveling to Salisbury. The port handles 1 million tons of cargo per year, making it the state’s second-largest water hub after Baltimore.

What’s different is where the dredged material is being placed. Typically, it has been unloaded wherever a willing landowner could be found and environmental hurdles could be cleared.

When Wicomico County and the Army Corps could no longer locate a suitable site on the lower half of the river a few years ago, they began looking farther afield. The partners prioritized sites at the greatest risk of washing away. A spot within the state’s 13,000-acre Deal Island Wildlife Management Area (WMA) easily fit the bill, they said.

This is a portion of Deal Island, MD, where
 dredged sediment is being pumped in

“You can see the marsh is breaking up,” said Curson as he displayed photographs during a virtual public meeting for the project.  The project entails mixing the dredged silt with water and pumping the resulting slurry through a temporary 9-mile pipeline. There, workers spray the material onto a 75-acre plot of badly eroded wetlands that lie between the Manokin River and the WMA’s main impoundment.

That phase of the project is scheduled for completion by mid-February. If all goes according to plan, the targeted acreage will receive 140,000 cubic yards of fresh earth, raising its height an average of 1.5 feet. The Army Corps plans to restore vegetation over two years by spreading seeds from the air and planting grasses by hand.

A second phase of dredging on the upper portion of the river is scheduled for late 2024, but that spoil is ticketed for a site near Salisbury.

Fortunately, there is no shortage of mud on the Eastern Shore. I'm shocked that they actually have to pipe it 9 miles. For a sparrow.