Along the western front
Spartina roots are strained, but they are easily cut. One stomp and the shovel sinks into the mud, water pooling up to the toes of Ferguson’s black rubber boots.
It was a warm, clear November day – too hot, according to Ferguson. She packed her bags for a cool fall day and was wearing a blue floral fleece, but 60 degrees means she will be sweating by noon.
Earlier in the week, Ferguson – along with a handful of DEM staff and volunteers – used shovels and a small excavator to dig a channel system through the swamp. These shallow streams will give the pooled water a route to Narragansett Bay, allowing the area to drain slowly.
If the root zone of the swamp plants is able to dry out even slightly, they will grow “healthy and happy,” Ferguson said. Healthy plants form a stronger root base, and a stronger root base makes a shoreline more resistant to erosion and sea level rise.
But “we don’t want to empty it too quickly,” she said. It’s been three days since they dug the first channels, and the water level has only dropped slightly, exposing a few inches of bare mud – exactly as expected.
Stagnant water is thick with unconsolidated sediment and topped with a bacterial mat. If the water drains suddenly, this sediment will flow into the bay. It is better to dig in phases and let it settle in the swamp, keeping it as high as possible.
They are back that day to adjust the channels, digging out areas where the mud has naturally dammed. Lucianna Faraone Coccia, a Save The Bay volunteer and a Masters of Environmental Science student at the University of Rhode Island, unearths a cluster of roots.
“If it’s in there, it might clog that whole channel,” said Faraone Coccia, looking down to point to a fiddler crab that was pushing its way along the channel with its out of balance claws.
With each full shovel, the water flow becomes stronger and stronger and the piles of peat dislodged next to the gullies grow larger.
“It’s technically considered a landfill,” Ferguson said, tossing another peat ball toward the heap next to her. “We actually leave the peat on the swamp and we create these little little islands. “
These islands are about a lump of peat – about 6 to 12 inches thick, not too high, Ferguson said – but that little rise “is like a mountain in a swamp.”
Ferguson fought to keep the peat in the swamp, securing additional permits from the Coastal Resource Management Board, DEM’s Office of Water Resources, and the Army Corps of Engineers. This microtopography is essential for a healthy swamp surface, she said.
“These areas will just be a little higher and they could recolonize,” Ferguson said. “And when I say power, they recolonize. “
In one season, the islands will welcome new spartina shoots, or they will prove to be tall and dry enough to support clusters of tall marsh grasses. The tall grass clusters will provide ideal nesting habitat for the salt marsh sparrow.
As healthy salt marshes have declined, the population of the salt marsh sparrow has declined, a bird that nests in a cup of dense tall marsh grasses. The nests are built to withstand the highest lunar tides, created with a dome so that “the eggs float, but they don’t float out of the nest,” Ferguson said. But the area is flooded too frequently, which contributes to nest failure.
“This is why these little islands that we are creating are really valuable habitat,” Ferguson said.