Home Cheap jerseys New Jersey’s intertidal wetlands could disappear due to rising seas, Rutgers study finds

New Jersey’s intertidal wetlands could disappear due to rising seas, Rutgers study finds


Sea-level rise is happening so rapidly that some of New Jersey’s major coastal marshes could be engulfed entire by the next century, eliminating critical wetlands that serve as habitat for wildlife and anti- storm, according to a recently published study by Rutgers.

The study authors present four potential ways to save swamps: buy from homeowners who live at the edge of wetlands, allow an invasive reed to spread, pump layers of new sediment to the tops of swamps, or build “shorelines. living “experimental.

“In the face of sea level rise, a marsh has two options – it can either increase its rise at a rate equal to that of sea level rise or migrate inland,” said the lead author Judith Weis, professor emeritus of biological sciences at Rutgers-Newark. “Otherwise, he will be overwhelmed and drowned. “

The study was published this week in the journal Anthropocene Coasts.

In New Jersey, intertidal marshes are the areas where the Atlantic Ocean and estuaries meet land. Key habitats for crabs, shrimps, birds and mammals, marshes are also essential for absorbing rain and preventing flooding during storms and waves. They absorb toxins, such as metals, and nitrogen to help reduce algal blooms. They also absorb carbon dioxide, a greenhouse gas and contributor to climate change.

Researchers looked at the data available for four locations: the Meadowlands and Raritan Bay in northern Jersey, and Delaware and Barnegat Bays in southern Jersey.

READ MORE: Protecting New Jersey’s Back Bays from Climate Change Storms Could Cost $ 16 billion, Federal Report Says

Weis said the team was struggling to determine the impact of sea level rise on the Meadowlands in Bergen County because there is so much human activity there, including straining conservation aimed at restoring wetlands, as well as intense development.

The authors found no change in the area of ​​the coastal marshes around Raritan Bay, just south of Staten Island, between 1986 and 2015, but said strong data for the area was lacking.

But they found a significant loss of wetlands around Barnegat Bay in Ocean County. The bay is fed by salt water from the Atlantic Ocean through a cove and mixes with fresh water sources, such as the Toms River. Previous analysis showed that about 12% of the bay’s intertidal wetlands were lost between 1972 and 2012.

In highly developed areas, swamps are often trapped between rising sea levels and infrastructure such as buildings, roads and developments, and simply cannot migrate inland.

The team found considerable erosion along Delaware Bay, where salt water from the Atlantic Ocean mixes with fresh water from the Delaware River. The bay is bordered by the counties of Cape May, Cumberland and Salem in New Jersey, as well as the counties of Sussex, Kent and New Castle in Delaware.

The study said that “most analyzes suggest that the Delaware Bay marshes are eroding and turning into open water” at a rate of 1.1% to 1.9% per decade.

However, Weis noted that the wetlands around Delaware Bay have room to migrate, unlike many wetlands in northern Jersey. Yet migration creates other problems as higher concentrations of seawater move behind the receding marshes. Salt water is deadly for the globally threatened Atlantic white cedar, for example.

READ MORE: Rising waters could turn Jersey’s coastal cedars into ghost forests

“The salt water rises more and more with the rise in sea level, and that’s what is killing these trees and creating ghost forests,” Weis said. “As swamps move inland, they convert forest to swamp. So the swamps win at the expense of the forests.

State Department of Environmental Protection announced last month a 10-year plan to restore 10,000 acres of Atlantic white cedar forests in the state’s Pinelands region. Trees, which can live up to 1,000 years, were killed along streams in lowland swamps. In New Jersey, Atlantic white cedar once occupied over 125,000 acres. It fell to less than 25,000.

Rutgers’ study makes it clear that sea level rise, the main force behind the loss, is not the only threat. Development, runoff, dredging and other man-made activities contribute to this.

Parts of the coast also sink naturally for geological reasons, which worsen the effect of sea level rise.

The researchers said swamps cannot increase their elevation as quickly as the sea rises. They note that the sea level is expected to rise by 2 to 5.2 feet between the base year 2000 and 2100 under a scenario of moderate greenhouse gas emissions. This increase would be greater if greenhouse gas emissions remained high.

Sea level rise along the mid-Atlantic is already above the global average.

READ MORE: South Jersey has the fastest sea level rise on the east coast, study finds

“If the area of ​​the marshes is reduced and coastal storms become more intense, coastal communities will lose their protection and suffer greater damage,” the authors wrote. “The reduction in marsh areas, which are nurseries for some commercial and recreational fish, will likely also result in reduced fish production.”

To reduce losses, the authors said municipalities could be encouraged to buy and demolish homes to prevent erosion. But Weis said the cost of such a “managed retirement” would be high and face political opposition. from New Jersey Acres Bleus program redeems willing owners in flood prone areas, but funding is limited.

Another strategy would be to pump thin layers of sediment from nearby streams to the marshes. The experiments turned out to be promising, but Weis also said it was costly as well.

The installation of so-called living shores prevents erosion by creating oyster reefs or barriers of shells, rocks, logs and other materials built on the edge of a swamp to protect it from waves. Another expensive option.

Weis said a promising – and inexpensive – strategy calls for stopping the elimination of invasive Phragmites. Reeds grow aggressively and supplant native plants and pose threats to native wildlife. Land managers have programs to eliminate them with herbicides and replace them with native cordgrass.

However, Weis said the reeds have proven to be good buffers, allowing swamps to rise faster than they normally would, as they create a protective layer when they die.

“This plant that has been seen as a villain may be how some swamps might survive sea level rise,” Weis said.


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