Salt Marsh Restoration

July 2017

Throughout May and June 2017, more than 200 volunteers planted salt marsh grass seedlings in the lower Narrow River, completing a multi-year plan to restore the area. Under the guidance of the US Fish and Wildlife Service (USFWS), volunteers of all ages removed salt marsh grass plugs from the trays in which they had been growing all winter long, loosened the roots, and tucked them into evenly spaced holes in areas of the marsh that had been raised in the dredging and elevation stage of the project that was completed in January 2017.

NRPA coordinated volunteer scheduling with Ben Gaspar, Biological Technician with USFWS, who provided training and onsite supervision. The collaboration resulted in the successful planting of all 35,000 salt marsh grass plugs. Gaspar reflects “It was wonderful to engage all different ages from the community in a very hands on way. The repeat volunteers and smiling faces at the end of plantings made it very worthwhile to facilitate the nature connection to the marsh.”

Volunteers included Narrow River Watershed residents, kayakers, fly fishers and others who care deeply for this valuable resource. Groups such as Lila Delman Real Estate, Fuss and O’Neill, Inc, Rhode Island Saltwater Anglers Association’s Kayak and Fly Fishing Committees, and the URI Men’s Rowing Team demonstrated their commitment to the river by helping to plant. Student groups from URI, Compass School, Meadowbrook Waldorf School, EnrichRI homeschool group, and more than 35 students and teachers from South Kingstown High School all brought their energy and enthusiasm to the planting.

Many volunteers expressed their appreciation for the opportunity to be a part of the restoration and health of the salt marshes. The collaboration of NRPA and USFWS for this stage of the project was a continuation of the cooperative joint effort of many entities throughout the restoration project, which included participation from Save the Bay, the Town of Narragansett, and the RI Coastal Resources Management Council. Over the next few years, USFWS will be monitoring the restored marshes and reporting on the longterm success of the project.

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April 2017

saltgrass (Disticis spicata)

cordgrass (Spartina alterniflora)

Narrow River Preservation Association is working with the US Fish and Wildlife Service on the next phase of the Narrow River salt marsh restoration project.

While the marsh has historically been underwater only at “spring” (new and full moon) tides, in recent years, due to sea level rise, the majority of the marsh is being flooded too frequently for the marsh grasses to thrive.

This winter, in partnership with the Nature Conservancy and the Coastal Resource Management Council, US Fish and Wildlife completed the dredging phase of the restoration project.

During this phase, using a method called thin layer deposition, crews dredged specific areas of the lower Narrow River and then dispersed the dredged material onto the surface of the marsh to raise the elevation. In areas where the elevation has been raised 3 inches or more, volunteers will soon plant marsh grass seedlings (plugs).

Marsh areas at the increased elevation will flood less frequently, which will hopefully increase the lifespan and resilience of the marsh to future sea level rise and other stressors.

Last fall, US Fish and Wildlife collected local seeds from three different types of salt marsh grasses along Narrow River. Since then, a nursery has been growing the seedlings (plugs).

Around the first of May, 35,000 plugs will be ready to plant.

The salt marsh grasses to be planted are cordgrass (Spartina alterniflora), saltmarsh hay (Spartina patens), and saltgrass (Disticis spicata).

The planting will occur over two or three days, with a morning and an afternoon shift each day. Volunteers will be able to choose which shifts they would like to work.

Volunteers are advised to dress for the weather. The work will be messy and rubber boots are encouraged. Helpers of all ages are welcome and NRPA is working with school groups who plan to volunteer. USF&WS will provide all of the needed tools and supplies as well as water and snacks.

The volunteer response at press time has been outstanding. Nearly 200 individuals and several groups have signed up to volunteer.

Many hands will make quick work of the 35,000 plugs.

Work has been ongoing since December 1, 2016 along the Narrow River as part of the salt marsh restoration and elevation pilot project, intended to combat drowning and increase the lifespan and resilience of the marsh to future sea level rise and other stressors. Contractor Patriot Marine has been dredging near Sedge Island under the supervision of the US Fish and Wildlife Service and the Coastal Resources Management Council.

Crews are using a restoration method called thin layer deposition to place dredged material on the surface of the marsh to raise the elevation so that plants can thrive. Material is dredged from select locations to create depths where eelgrass can grow, creating an important habitat. The dredged materials are then dispersed on the adjacent marsh surface to slightly increase the marsh’s elevation, primarily in areas where the vegetation has died off or become stressed from prolonged flooding. These areas will be replanted with marsh grasses.

From Narrow River Kayaks south to Sedge Island, the dredge footprint creates an approximately 65-foot wide channel in the river. Sand from the river is being used to elevate the marshes on the eastern side and on Sedge Island.

This photograph (taken December 13, 2016) showing an astronomically high tide, gives a good sense of what the project is trying to accomplish. The entire marsh is under water with the exception of the mound of material being pumped onto the marsh. While the marsh should be underwater during “spring” (new and full moon) tides, the majority of the marsh is being flooded too frequently. The mound of material will be graded with low ground pressure equipment to raise the marsh plain. Increasing marsh elevation will also benefit the Saltmarsh Sparrow, a species of concern, which nests in the marsh grass.

NRPA is organizing volunteers to plant salt marsh grass plugs early in the spring under the supervision of the US Fish and Wildlife Service as part of the restoration efforts.

This aerial video by East Greenwich Resident Ray Stachelek clearly shows the phases of the dredging and salt marsh restoration project that took place in November and December 2016. New phases of work will continue through 2017.

March 2015

For the third and final presentation of the 2015 On Pettaquamscutt winter speaker series, Wenley Ferguson of Save the Bay and Nick Ernst of USFWS explained the various strategies for marsh adaptation being used in Narrow River and throughout the Narragansett Bay Estuary.

Some of the tools in the Narrow River strategy include:

• Dredging in selected locations to improve channel flow and promote eel grass growth
• Marsh edge protection using coir logs and bagged oyster shells (a method also being evaluated near Middlebridge)
• Digging runnels and repairing existing ones to improve surface drainage.

On March 23, the R.I. Coastal Resources Management Council and U.S. Fish & Wildlife Service began a marsh restoration pilot study on the marsh just south of Middlebridge. The pilot is comparing two methods of “thin-layer deposition” in which a layer of sand is used to raise the elevation of the marsh surface and thus enable the marsh to keep up with sea level rise.

The pilot will compare the results of two 50 by 100 foot plots where roughly four inches (100 cubic yards) of sand were added.

With the hydraulic method used for the first plot, water, air and sand were combined in a tank and pumped onto the marsh.

In the second plot, the layer of sand was spread using a Bobcat loader.

USFWS scientists will be measuring sediment levels, vegetation response and peat compression (soil bulk density) throughout the year to help inform suggested methods for larger scale thin-layer deposition of material dredged from Narrow River later this year.

The work is part of a multi-prong USFWS effort to restore estuarine conditions in the John H. Chafee National Wildlife Refuge in the Narrow River to enhance resiliency against sea level rise, climate change and future storm events.