Photo: Jim O'Neill
Jacob's Point Salt Marsh
Our primary study location is Jacob's Point Salt Marsh in Warren, Rhode Island. The marsh is owned and managed by the Warren Land Conservation Trust which has graciously granted our research team access to the site for the five-year study period. The site is approximately 35 acres (14-ha) along the northeast shore of Narragansett Bay as the bay narrows to form Warren harbor. The site borders Rhode Island Audubon's Claire D. McIntosh Wildlife Refuge with its Nature Center, Aquarium and boardwalk. (The study site is a half mile walk from the Nature Center parking lot). The East Bay Bike Path borders the study site on its eastern edge, providing another way to access the site.
A narrow sand/upland-barrier ridge separates the marsh from the bay. Tidal waters enter the estuary via two tidal channels that breach the ridge and flow east and south, respectively, into the marsh interior. The extreme southern segment of the marsh is separated from the larger wetland by an elevated road-bed constructed in the 1930s. Tidal flow is maintained to this southern tract via three, 1.5-m culverts running north-south beneath the road-bed along the courses of the original marsh channels. The regular cycle of the tides provides the conditions needed to sustain the Saltmarsh Sparrow and the other animals and plants of this micro environment.
The Jacob’s Point marsh is dominated by “salt meadow” communities of the high marsh. The salt meadow grassland is comprised of stands or mixed communities of salt marsh hay (Spartina patens) , spike grass (Distichlis spicata), and black grass (Juncus gerardi). In the eastern one-half of the marsh, and south of the road-bed, the salt meadow community transitions gradually to include the shrubby plant, high tide bush (Iva frutescens) where the land is slightly higher above sea level. High tide bush occurs in dense clumps with sparse grassy growth beneath, and in a band of dense, shrubby habitat along marsh-upland edges. Salt marsh cordgrass (Spartina alterniflora) occurs in two forms at Jacob’s Point: (1) a tall form (more than 1 meter) grows within the regularly-flooded intertidal zone along the upper elevations of creek- and ditch banks (“low marsh”); and (2) a shorter form (less than 1 meter), “high-marsh" cordgrass, which grows in small patches on the high marsh where it intergrades with the salt meadow grasses. This mix of grasses and bushes is essential to the nesting requirements of Saltmarsh Sparrows.