Saltwater marshes are among nature’s most productive ecosystems, a base for the web of aquatic life. Their vegetation feeds microbes and insects that are eaten by crustaceans, fish and mussels — which in turn become prey for birds and bigger fish and turtles coming in with the tide. The top of that food chain supports South Jersey’s wildlife tourism and sport and commercial fishing industries.
The region got great news this month when a study of the Mid-Atlantic and Northeast coasts determined the marshes of South Jersey are exceptionally well-positioned to survive and even expand in this century’s expected sea level rise.
One area in particular — the salt marshes along the Delaware Bayshore — were deemed “the largest, most resilient area in the whole region,” said Mark Anderson, the author of the study by the Nature Conservancy and funded by the U.S. Fish & Wildlife Service.
Other local areas with outstanding resiliency include the McNamara Wildlife Management Area at Tuckahoe, Island Beach State Park, and the Mullica River estuary/Forsythe National Wildlife Refuge.
A sea level rise of 1 to 4 feet is expected by the year 2100, according to a report this month from the U.S. Global Change Research Program.
Anderson, the conservancy’s science director in the East, said the Great Egg Harbor estuary in the Tuckahoe area would be sustainable even with a sea-level rise of 6 feet.
The study evaluated 10,000 coastal areas with a new Resilient Land Mapping Tool for the conditions that will allow marshes to survive rising seas — room to migrate inland, a gentle slope that allows migration, and appropriate sediments and water quality.
Marshes behind barrier islands are much more vulnerable because they typically have nowhere to go. With higher sea levels, many would turn into ribbons of marsh as barrier islands were submerged, Anderson said.
That resilient marshes still exist isn’t an accident of nature, but a result of successful protection and acquisition programs. Most of the Great Egg Harbor estuary, for example, has been purchased and preserved by the state Division of Fish and Wildlife, including 17,500 acres in the Tuckahoe WMA alone. Atlantic County has preserved thousands of acres more in its park system.
The purpose of the study was to determine where conservation resources and efforts will produce the best results, so the great resilience of South Jersey’s marshes will assure that they’ll get programs and funding to preserve and enhance them.
The study said 83 percent of existing tidal habitats in the Northeast and Mid-Atlantic could be lost to rising seas, but the proper management of resilient sites could offset half of such habitat loss.
That would not only continue to provide critical habitat for fish, birds and other wildlife, it would also provide a buffer from storms and flooding for people living inland.
South Jersey, already known for its salt-marsh habitats and wildlife, looks like it will have the best salt-marsh ecosystems in the most densely populated part of America. We hope governmental entities at all levels help make that happen.