South Jersey is home to some of the best places on the East Coast for marshes, plants and animals to survive sea level rise, according to a new study by The Nature Conservancy funded by the U.S. Fish & Wildlife Service.
The study looked at more than 10,000 coastal sites in the Northeast and Mid-Atlantic to see where conditions are right for marshes to migrate inland as sea level rises.
That migration would allow the marsh to continue to provide habitat for fish, birds and other wildlife. It also would protect property farther inland from flooding, said study author Mark Anderson, science director for TNC’s Eastern region.
“The Delaware Bayshore is the largest, most resilient area in the whole region,” Anderson said. It has room for the marsh to migrate, a gentle rather than steep slope to nearby lowlands, enough of the right sediments available, and good water quality.
“That area just looks really about the best area in the East for those conditions,” he said.
Other areas that stood out as best able to absorb sea level rise include the Lester G. MacNamara (Tuckahoe) Wildlife Management Area on the Great Egg Harbor River, Island Beach State Park, the Mullica River and Great Bay, which includes Forsythe National Wildlife Refuge.
“On the South Jersey coastline, the area around Tuckahoe is one of our poster children for a great place,” Anderson said. “Migration could happen and coastal systems could be sustained, even with up to a 6-foot sea level rise.”
He said 6 feet is the maximum sea level rise considered possible by the end of this century, while the rise is expected to be something more than 2 feet for sure.
Rutgers University Professor Robert E. Kopp, one of the authors of the Climate Science Special Report released last week by the U.S. Global Change Research Program, has said the report found global average sea level will likely rise by 1 to 4 feet over this century, with the higher values more likely with more carbon emissions.
The report also warned sea level could rise by as much as 8 feet, if Antarctica’s ice proves more unstable than currently thought.
Rising seas already have caused a fivefold to tenfold increase in tidal flooding since the 1960s in several American coastal cities, including in New Jersey, Kopp has said.
“I am not surprised that the Great Egg Harbor Estuary received a Resilience Score far above average,” said River Administrator Fred Akers, who oversees local management of the river under the National Wild and Scenic River System.
He said the state Division of Fish and Wildlife has purchased and preserved most of the estuary, including adjacent uplands, through the creation of Wildlife Management Areas and preserves. The Tuckahoe WMA alone preserved more than 17,500 acres, he said.
It has been a priority for open space preservation for the New Jersey Green Acres program, Akers said. Recently, Green Acres purchased 5,000 acres around Gibson Creek and Stephen Creek for $10 million, Akers said.
Atlantic County also has preserved thousands of acres of the tidal estuary and nearby uplands in its park system, he said.
The barrier islands are a different story, Anderson said.
“The barrier islands look much more vulnerable than the bayshore,” said Anderson. Many of them would virtually disappear underwater, and the marshes on their bayside would have little space to migrate, so would likely end up as ribbons of marsh, he said.
TNC wants the study to help land preservation efforts be targeted to places that can most protect against sea level rise.
“With no action, (the Northeast and mid-Atlantic) could see an 83 percent loss of existing tidal habitats to severe inundation,” the study’s executive report said. “But with proper management, there are thousands of individual sites where tidal habitats could increase and expand through landward migration, reversing this trend.”
The study estimated the resilient sites could offset more than 50 percent of tidal habitat loss, “providing critical habitat for birds and wildlife, and buffering people from the effects of storms and floods.”
The sites identified as best able to handle migrating marshes in South Jersey are in places that are already largely conserved, which is a big plus for the region, Anderson said.