Located approximately 6.5 miles southeast of Providence, this IBA spans the municipalities of Barrington and East Providence. Contiguous wetland habitat lies upstream along the Runnins River over the border into Massachusetts. The IBA is surrounded by lands representing a variety of land use including commercial, institutional, residential, agricultural, and recreational uses.

{link:For IBA map, click here.|http://www.audubon.org/bird/iba/maps/RI/RI3500m_HAC09.pdf}

Ornithological Summary

The salt marsh system included within this IBA is the third largest salt marsh estuary in Rhode Island. This system provides important breeding populations of Clapper Rail (Rallus longirostris), Seaside Sparrow (Ammodramus maritima), and Marsh Wren (Cistothorus palustris). A colony of Common Tern (Sterna hirundo) historically nested on "The Tongue" a spit of marsh that bisects the cove*.

* http://library.fws.gov/pubs5/necas/web_link/32_hundred%20acre%20cove.htm

Some comprehensive work on salt marsh sparrows was conducted in this marsh back in the early 80?s by Steve Reinert, where he reported (for example) in 1981 a total of 16 pairs (12 nests found) in the northeast section alone. Adding the additional salt marsh habitat in the northeast section, and in the cove and lower Runnins River, Walter Berry of the USEPA Office in Rhode Island was able to record 58 individuals during a survey conducted in 2007.

Survey efforts in 2007 also revealed the presence of Willets in suitable nesting habitat during the breeding season (7 birdes counted), and 9 Seaside Sparrows. The marsh also likely provides suitable habitat for nesting rails, and foraging habitat for various long-legged waders. During late fall, winter, and early spring months, large concentrations of bay ducks can be found in the cove and the adjacent Runnins River.

The area of Hundred Acre Cove known as "The Tongue" is also the only known breeding locality of the Diamonded Back Terrapin (Malaclemys terrapin) in Rhode Island (R. Enser - personal communication).

Conservation Issues

Sea-level rise threatens the marsh as development in the upland has encroached to the edge of the marshes and other fringing wetlands around Hundred Acre Cove and the Runnings River. Under this scenario, the high marsh zone (the habitat of the Saltmarsh Sharp-tailed Sparrow) is prevented from moving landward and thus subject to more frequent flooding and floods of longer duration. Such flooding events result in a greater number of Saltmarsh Sharp-tailed Sparrow nest failures.

Stands of Phragmites on the western edge of the IBA suggest nutrient and stormwater input/runoff to the system from adjacent development. Phragmites invasion of the marsh is detrimental to the high marsh habitat of the Saltmarsh Sharp-tailed Sparrow as Phragmites begins to out-compete Spartina patens, Juncus gerardii, and other high-marsh vegetation required by this species for nesting.

Predation is often a significant cause of Saltmarsh Sharp-tailed Sparrow nest failures. Increased predation rates due to the attraction of opportunistic predators to human-disturbed environments is a concern in fragmented landscapes surrounded by continuing human development.

Ownership

Approximately 46.1% of the IBA is open water. The land within and around Hundred Acre Cove is under various ownerships including the Audubon Society of Rhode Island (ASRI), two municipalities (i.e., the Town of Barrington and the East Providence Conservation Commission), two land trusts (the Barrington Land Trust and the East Providence Land Conservation Trust), and various private entities.

Habitat

Almost half (46.1%) of this IBA consists of open water associated with the Runnings River Estuary. A large percentage (23.8%) is composed of saltmarsh habitat which includes areas suitable for nesting Saltmarsh Sharp-tailed Sparrow, a species of global conservation concern. Minor habitat areas consist of beach, brackish (phragmites -dominated) marsh; shrub swamp, or a mixture of one or more of the following: pannes, pools, and tidal flats.

Land Use

The majority of this IBA (81.7%) is composed collectively of open water (49.1%) and wetland (32.6%), while remaining undeveloped areas are composed of either shrubland (2.0%), deciduous forest (8.9%), or mixed forest (0.8%).

Open water areas support fishing, boating, and other water dependent uses. Wetlands provide hunting opportunities and support various passive recreational activities such as birdwatching, nature study, photography, etc.

Stay abreast of Audubon

Our email newsletter shares the latest programs and initiatives.