By
FRANK CARINI/ecoRI News staff
 |
| Photos by Will Collette |
These unique ecosystems are a priceless resource with
irreplaceable benefits to both people and wildlife. The Ocean State is losing
and has lost thousands acres of salt marsh to development and a changing
climate.
It’s been estimated that the state has lost about 60 percent of its
salt marshes, many of which were filled with mud and sand dredged during
navigation projects or filled in with other waste materials. Downtown
Providence, for instance, was once known as the Great Salt Cove, prior to its
filling.
Salt marshes are the protectors of Rhode Island’s most important
cultural, economic and environmental resource, Narragansett Bay.
But more than
50 percent of the bay’s salt marshes have been destroyed during the past three
centuries. Much of the remaining marshes have been diminished by coastal
development, a changing climate and mosquito ditching. Mosquito ditches are
narrow channels that were dug to drain the upper reaches of salt marshes.
It
was believed that such efforts would control mosquito breeding, but all that
work did was drain salt marshes and kill off mummichogs, a mosquito-eating fish
that are important prey for herons, egrets and larger predatory fish.
Salt marshes are shoreline wetlands that are flooded and drained
by salt water brought in by the tides. These intertidal ecosystems — foraging
habitat for fish, shellfish, birds and mammals, and home to nursery areas and
spawning grounds — are essential for healthy coastlines, communities and
fisheries. They are an integral part of Rhode Island’s economy and culture.
Salt marshes play an important role in Rhode Island’s
fishing/shellfishing industry. The economic value of
salt marshes related to recreational and commercial fishing activities is
estimated to be $6,417 an acre, according to James Boyd of the Coastal
Resources Management Council (CRMC).
They help Rhode Island’s tourism/outdoor-recreation industry
generate some $2 billion annually. The many vistas afforded by the state’s
salt-marsh landscape also contribute immeasurably to the Ocean State’s beauty
and peacefulness.
Healthy salt marshes help communities, buildings, infrastructure
and the environment better withstand the impacts of sea-level rise and coastal
storm surge. Salt marshes protect shorelines from erosion by buffering wave
action and trapping sediment. These vital ecosystems reduce flooding by
absorbing rainwater, and protect water quality by filtering runoff and
metabolizing excess nutrients, such as nitrogen.
But storm surge and wave erosion, combined with the lack of
replenishment from estuaries whose rivers have been dammed or choked off by
centuries of development, have left once-hardy tidal-marsh ecosystems at a
point where salt-marsh elevations can’t keep up with sea-level rise, according
to Jennifer White, a biologist with the U.S. Fish & Wildlife Service.
For example, the coastal portion of the Sapowet Marsh Wildlife Management
Area in Tiverton has experienced more than 90 feet of shoreline
erosion in the past 75 years, according to the Rhode Island Department of
Environmental Management (DEM).
The Nature Conservancy and the U.S. Fish & Wildlife Service
are working to restore and strengthen salt-marsh habitat at Sachuest Point National Wildlife
Refuge in Middletown to better withstand the impacts of
sea-level rise, coastal storm surge and coastal erosion.
The East Coast, from North Carolina to Boston, is considered a hot
spot for sea-level rise, with coastal waters climbing three to four times
faster than the global average, according to the U.S. Geologic Survey.
The current sea-level rise estimates for
Rhode Island are a foot by 2035, 2 feet by 2050 and 7 feet by 2100. Areas at
most risk for sea-level rise — Barrington, Charlestown, Narragansett, North
Kingstown, Warren and Westerly — are already experiencing the death of salt
marshes. A 5-foot rise in sea level is expected to wipe out 87 percent of the
state’s remaining 4,000 acres of coastal wetlands, according to CRMC.
Although coastal areas go through natural periods of change, there
has been a net loss of sediment during the past few decades in Rhode Island,
according to CRMC’s Shoreline Change Special Area
Management Area (Beach SAMP), and many municipalities have
faced or are facing erosion issues on both public and private beaches. The
agency also has noted that the most eroded portions of Rhode Island’s coastline
have lost more than 250 feet of beach in the past 50 years.
Salt marshes and other wetlands are highly sensitive to
development, which can disrupt their highly valued services. Polluted
stormwater runoff from inland development can damage salt-marsh health.
This
runoff from roads and other impervious surfaces, and nutrient-rich runoff from
fertilized lawns and agricultural areas and from septic systems and cesspools,
also can degrade freshwater wetlands.
Balancing development interests with a healthy environment is a
difficult task, especially when the policies, regulations and guidelines that
govern development are constantly under attack, underenforced or ignored.
Threats of litigation, special interests and a state economic
development plan that preaches “cranes in the sky” are applying considerable
pressure on the Ocean State’s dwindling collection of healthy salt marsh.
Art Ganz, president of the Salt Ponds Coalition, told ecoRI News late
last year that no one is enforcing coastal development. “We have the tools,
like the Beach SAMP and Stormtools, that do a
good job planning and thinking about the changing coastline and how it should
be developed, but there’s been no implementation yet. Nobody wants to be the
first guy to say no and get slapped with a lawsuit.”
During the 2016 General Assembly sessions developers were given a
boost with the passage of the wetland buffer bill that
allowed wetland buffers to be included in determining the number of homes or
apartments that can be built on a parcel.
The legislation was a surprise follow-up of
a law passed in 2015 that allows the state to establish universal protective
zones for freshwater wetlands. Rhode Island development was given a similar
boost in 2013, with passage of a law allowing unbuildable sloped land to
be included in lot sizes.
Ganz, who retired from DEM’s Department of Natural Resources in
2005 after 35 years, noted that despite CRMC cease-and-desist orders
development continued along Green Hill Beach in
South Kingstown. He said some of the properties there will be under 5-9 feet of
water when the next 100-year storm strikes.
“Coastal planning is ignored and the problem keeps magnifying as
we keep developing places,” Ganz said. “The awareness is there but enforcement
is lacking. We’re using taxpayer money to
jack up houses that should have never been built. Where are we going? I don’t
know.”