Inland Bays marshes are breaking apart, forming pockets of open water. That is one of the most significant findings in a three-year study on the Inland Bays by a group of University of Delaware scientists. The process is similar to what is occurring in Prime Hook and Bombay Hook National Wildlife Refuges.
Andrew Homsey, associate policy scientist at the University of Delaware's Institute for Public Administration, released preliminary results of the team's research during a June 7 Center for the Inland Bays Science and Technical Advisory Committee meeting.
Digitized images dating back to 1938 provide proof of what is occurring, but Homsey said more study is needed to determine the cause of the change. “It could be tied to increasing storm activity, the deepening of the inlet and the hardening of the shoreline,” he said. Other factors could include sea level rise, ditching and a lack of sediment.
He called the change from 1992 to 2007 significant. “Areas went from degraded marsh to open water,” he said. However, he said, spartina marsh is holding its own and loss seems to be leveling off.
The team's research shows how much has disappeared. About 1,000 acres of wetlands have been lost in the Little Assawoman Bay area; 625 acres along Rehoboth Bay; and 275 acres along Indian River Bay, the three bays of the Inland Bays system.
The research, which demonstrates historic changes in the area around the Inland Bays, shows dramatic changes in land use including increased development, decreased farming and numerous manmade canals. The study, funded by the Environmental Protection Agency in coordination with the Center for the Inland Bays and the Delaware Department of Natural Resources and Environmental Control, provides longterm data on tidal records and changes in sea level and tidal range as well as marsh conditions from images taken in 1938, 1968, 1992 and 2007.
Susan Guiteras, U.S. Fish and Wildlife Service regional biologist, said most people are aware that marsh in Prime Hook refuge is degrading because of coastal breaches, but what isn't as evident to most people is what is taking place at Bombay Hook refuge, north of Prime Hook along the Delaware Bay.
“We are seeing interior marsh loss as wetlands break apart to open water,” she said. “The number of snow geese are a factor – and are making it worse – but they are not the only reason.”
Sea level rise planning factor for state parks
The committee also heard a presentation by Matt Chesser, who said state park planners have changed the way they do their work because of sea level rise and climate change. Chesser is administrator of the state Division of Parks and Recreation's planning, preservation and development section.
Cheeser said research shows that 381 miles of Delaware's shoreline is at risk for sea level rise, and many state parks facilities are in that area, including two of the most popular parks in the state. Cape Henlopen State Park near Lewes and Delaware Seashore State Park at Indian River Inlet attract about half of the 4.7 million annual state park visitors. He said retreat from those areas is not an option as more and more people come to the parks. “Tourism is becoming our largest industry,” he said.
He said park planners are taking a more serious look at placement of buildings to keep them away from flood-prone areas, and they are also looking to purchase land in areas away from flood plains, instead of placing a priority on purchasing wetlands.
They are also upgrading evacuation procedures and emergency plans to get people out of parks quickly and developing pre-storm notification systems.
He used recent work at Delaware State Park as an example. The new state park office and the marina office were consolidated into one new building; the old park office on the ocean side of the park was abandoned.
“This presents a lower risk. We moved the office to a lower hazard zone to the bay side,” he said.
Another building in the park, the day-use facility on the southeast side of the inlet near the beach, was refurbished instead of being torn down and rebuilt. “We did not build new; this is a different way of doing things for us,” he said.