the ocean is knocking at the front door of some beachfront homes and
hotels in North Carolina, the forests across the Albemarle and Pamlico
sounds are retreating from the shoreline.
being driven back by saltwater. It’s seeping into the soil and surface
waters of the coastal plain. What scientists call “saltwater intrusion”
has been going on since the oceans began rising when great ice sheets
started melting 20,000 years ago. But salt’s slow movement inland has
accelerated in recent years, those scientists say.
also say it has the ability to transform freshwater landscapes long
before they are permanently drowned by the rising sea. The locals know
ask Scott Lanier, manager of Alligator River National Wildlife Refuge –
the refuge sits on the eastern tip of the Albemarle-Pamlico peninsula,
which juts into the two sounds like a bottom jawbone. “I can just tell
you,” he says, “places where I used to walk in the marsh off of Point
Peter Road and hunt here early in my career, now I could take a boat
and fish in them.”
started working at the refuge when it was established in 1985 and has
spent about 15 years there. He’s noticed some significant changes to
Alligator River refuge we’re losing actual land base,” Lanier says.
“We’re losing forest, especially on the areas that are adjacent to the
sound. We’re seeing these areas be converted from forest to shrub.”
signs of saltwater intrusion are subtle ones. Plant growth slows to a
halt. There are fewer seeds, or the seeds that are dropped on the
ground have a harder time germinating. High salt concentrations can
draw water out of plants cells, stressing them out. The vegetation’s
struggle to survive the salt, however, is not the only thing changing.
intrusion eats away at the peninsula’s peat soil, lowering an elevation
that is, on average, only two feet or less above sea level. Peat is a
soil rich with organic plant litter that’s common in wet, acidic areas,
and saltwater breaks it down faster. “When the soil decomposes, the
elevation of the ground literally drops,” says Christine Pickens,
coastal restoration and adaptation specialist of The Nature
Conservancy’s N.C. chapter. “It’s called subsidence.”
top of that,” Pickens says, “the whole peninsula, well most of it, has
been ditched and drained. These ditches allow the saltwater to work its
way into the interior parts of the peninsula and chew away at that soil.”
of the eastern seaboard’s coastal plain has a similarly low elevation.
What makes this region particularly prone to saltwater intrusion,
Pickens says, is its extensive network of ditches and canals used for
farming. What farmers use to drain excess water from their crop fields
to the nearby sounds and creeks is precisely the conduit for saltwater
to reach them.
is farm country in the coastal plain of North Carolina between the
Albemarle and Pamlico sounds. It’s some of the most productive
agricultural land in the state and it’s surrounded by the
second-largest estuary in the nation.
down U.S. 264, through Hyde County, the first thing you’ll notice are
ditches filled with water that run like a narrow moat parallel to the
road. Then, you notice how most all the houses in the countryside sit
three or four feet above the ground on gray concrete blocks. The crop
rows, waiting to be planted after the winter, are saturated with water.
it’s the dead standing pine trees you see that give you the most pause.
They’ve shed their needles, branches and dark brown bark. The trunks,
pale as ghosts, loom in the marsh and green shrubbery like phantoms.
These “ghost forests,” as they’re sometimes called, are all that remain
of tress that can’t handle the encroaching saltwater.
something the farmers are already dealing with every year, says Mac
Gibbs, the former director for the Hyde County Center of the N.C.
Cooperative Extension Service for 25 years. He’s worked locally as a
farmer and commercial fisherman, too.
was born and raised in Engelhard, a small fishing community in Hyde
County, and lives on a property that his grandfather owned and farmed
that backs up to the Pamlico Sound.
losing land all the time,” he says. “There are areas that used to be
farmed in the late 1800s that are pure marsh now, and I’m talking about
for the crops, Gibbs says today the saltwater affects only crops that
are within a half mile of the creeks or, worst case, within a mile.
call it ‘saltwater intrusion,’ and I guess that’s the first sign of
sea-level rise,” Gibbs says. “At first it starts affecting the yield,
but then there’s sections of land, once it gets salt enough you can’t
puts up the best fight, he notes. And some farmers have tried
introducing a more salt-tolerant soybean, though the yields aren’t up
“Is it in their (the farmers) daily lives? Yes. Do they talk about it every day at the store? No,” Gibbs says.
can get the land back,” he adds, by pumping and diking or building tide
gates to keep the saltwater off, but it can be expensive. Farmers are
constantly comparing the tradeoff.
the county next door though, the evidence is clear that the land is
changing rapidly, says Dennis Stewart, the refuge’s wildlife biologist.
Refuge scientists several years ago compared photos from the 1990s to
2012, he explained, and did some crude calculations. “Eight to 10
thousand acres had transitioned from forested wetlands to marsh,” he
forested wetlands made up of bald cypress and pine trees, which are
home to deer, bear, pileated woodpeckers and other critters, are
gradually retreating and transforming into salt marsh. And while
there’s always been a fringe of marsh between the sound and the forests
on the refuge, Stewart says, in the past they were relatively narrow
compared to today.
you look at it over successional time, it’s happening pretty fast,”
Stewart says. “Within a three- to five-year period you can go from a
forested wetland to a shrub-dominated wetland with a lot of tree snags
(standing dead or dying tree). And then from a five- to 10-year period,
you go from a shrub-dominate wetland to predominately marsh, still with
changes, he adds, will affect wildlife. “Those forest-dwelling species
are not going to use the marsh so they’re going to have to move to
other forested areas. And then the marsh species are going to love it
because they’re going to get more marsh.”
land managers are taking a more proactive approach, Lanier and Stewart
both say, by starting to think about how they can adaptively manage the
land to buy just a little more time for wildlife to move “up-gradient.”
it’s humbling to know things may not be here forever,” says Lanier.
But, at least, he says, they’re trying to do something about it: “I get
a lot of satisfaction out of the fact that we’re not just sitting back
and watching things happen.”
“I think the hardest part about it,” he says, “is knowing we can only do as much as we can afford.”
MORE ON SALTWATER INTRUSION
Five researchers across several disciplines are joining forces to
investigate the future risks of saltwater intrusion in this region and
how its locals will ultimately play a role in conserving the land, or
not. Click here to read Part Two.
Part Three: How
increasing saltwater intrusion in North Carolina will affect trees,
soil nutrients, water quality and climate-altering greenhouse gasses. Click here to read Part Three.
article is provided by Coastal Review Online, an online news service
covering North Carolina's coast. For more news, features, and
information about the coast, go to www.coastalreview.org.)