Marshlands along the New Jersey coast may disappear in the next 100 years without extensive mitigation efforts, according to a new study led by a team of Rutgers researchers.
Tidal marshes are ecologically and environmentally sensitive areas between land and ocean that are susceptible to impacts from sea level rise. They absorb pollutants and sequester carbon, and are home to dozens of iconic birds, mammals and sea creatures.
The study found some marshes in the Garden State are losing ground due to sea level rise. As lead author Judith Weis, a professor emerita of biological sciences at Rutgers-Newark, explains: “Faced with sea level rise, a marsh has two options—it can either increase its elevation at a rate equal to that of sea level rise or it can migrate inland. … Otherwise, it will be submerged and drown.”
The study focused on four marshes in NJ: the Meadowlands, Raritan Bay, Barnegat Bay and Delaware Bay, tracking horizontal and vertical levels over time.
The losses couldn’t quite be determined in the Meadowlands, due to the amount of development in the area. And Raritan Bay got a relatively good report; though, of course, the future of warming, rising sea levels could—and very well will—have an impact on those areas.
Barnegat and Delaware Bays, however, are already experiencing loss from erosion. In Delaware Bay, ghost forests—where trees die from salt water exposure—are cropping up as marshlands migrate inland.
Though most marshes in the state are not increasing in elevation as quickly as sea level is rising, two marshes in the Meadowlands have risen in concert with the sea level, and researchers say it’s due to an invasive species of reed. The reed limits biodiversity, but it could save the marsh, it appears.
In fact, killing fewer of the reeds (which is done with toxic chemicals) is one of four potential solutions the researchers laid out to ebb marsh declines.
“Some reeds should be left on the marsh surface to give the marsh a better chance of keeping up with sea level rise,” says Weis. “This will be controversial and likely opposed by many marsh managers, which will require a revolutionary change in marsh management.”
Another option is a similarly controversial idea to encourage towns to buy and demolish houses that prevent marshes from migrating inland. (Good luck with that…)
The other two options: Adding new sediment atop marshes that aren’t rising as quickly as they need to; and using experimental techniques, like this: “Harder materials, preferably oyster or mussel reefs but sometimes concrete blocks, can be placed in front of the marsh edge to shield waves that erode the marsh edge.”
Experiments like that are playing out along NJ marshlands today. Reasonable solutions are welcome, and soon, as the mid-Atlantic is one of the world’s coastal areas that is experiencing the highest sea level rise due to geophysical reasons.