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Status: Recognized IBA
Ownership: State of Connecticut/Department of Environmental Protection, Guilford Land Conservation Trust, Madison Land Conservation Trust, Town of Guilford, Audubon Connecticut
Nominator: Leslie Kane, Environmental Planner, Town of Guilford
Size: ~1000+ Acres
Location: 73° 6’ W, 41° 10’ N

Habitats:
Primary—Brackish tidal marsh, estuary
Secondary—Deciduous forest, tidal freshwater marsh, river/stream

Land Use:
Primary—Hunting/fishing, Nature and wildlife conservation
Secondary—Utility/right-of-way

Threats:
Serious—Introduced animals, pollution, habitat conversion, Hydrologic changes (rising sea level), development (on upland borders)
Minor—Invasive or non-native plants, predators

The East and West River Marsh Complex, located in Guilford and Madison, is one of Connecticut's first globally significant IBAs. Large numbers of the globally vulnerable Saltmarsh Sharp-tailed Sparrow nest in the hundreds of acres of high quality salt meadow habitats of the marsh. Photo by Paul J. Fusco.

Site Description: The East and West Rivers and their tidal marshes join together at their outlet into Long Island Sound. This complex of tidal marshes is important for many different bird species during their migratory routes in spring and fall, as well as for breeding grounds in season. There are significant areas of protected lands held by the Connecticut Department of Environmental Protection (DEP), Audubon Connecticut, Guilford Land Conservation Trust, and the Town of Guilford. Even though there are many acres of protected brackish tidal marsh, there are upland areas that are developed or under threat of development.

IBA Criteria: Connecticut Endangered and Threatened species; High Conservation Priority Species; Rare, Unique or Representative Habitat; 500+ Waterfowl (winter) 1000+ Waterfowl (staging); 100+ Terns/500+ gulls; 500+ Shorebirds; 25+ Breeding pairs/100+ Individual Staging, Feeding Wading Birds; Exceptional Concentrations of Migratory Landbirds; Single Species Concentrations; Long-term Research and/or Monitoring.

Birds: This site, including the East River Saltmarsh Wildlife Management area is an extremely important breeding site for Saltmarsh Sharp-tailed and Seaside Sparrows, both state-listed species. Partners in Flight has estimated that Saltmarsh Sharp-tailed Sparrows have the highest proportion of their global population in southern New England, with an estimate of half of the world population breeding in Southern New England. Early indications from a study currently underway (2004) indicate extremely high densities of Saltmarsh Sharp-tailed Sparrows nesting in the marsh. In addition, the marsh complex is also an important site for migrating shorebirds during spring and fall. At least one location within the marsh complex, a Phragmites control project, gets extensive use by feeding shorebirds in the migration season. The marsh complex is used extensively by Great and Snowy Egrets for foraging in the breeding and post-nesting dispersal seasons, and the Common Terns that nest on Falkner Island regularly forage in the marsh.

Non-avian Resources: Historically, these marshes have been used for salt hay. East River Marsh provides habitat for a state endangered mammal and state special concern insect species. It is the only area remaining in the state for at least one state endangered plant species. West River Marsh is used by Diamond-backed Terrapins throughout the summer.

Existing Conservation Measures: Studies are ongoing regarding Sluice Creek. The East and West River salt marshes carry heavy sediment loads and are dredged to improve their channels on a somewhat regular basis. Flow issues in the upper reaches of the West River salt marsh have been modified with a new bridge constructed on Route 146. The increased span of this bridge affords a higher tidal reach, and is improving the habitat north of Route 146. Long Cove is the site of Connecticut DEP salt marsh restoration work. The quality of habitats here has increased dramatically and migrating bird counts are up. A study of Saltmarsh Sharp-tailed Sparrows began in the summer of 2002 with the goal of obtaining information about population sizes, habitat needs and trends of this species. This information will be used to determine how the marshes can be most effectively managed to support large populations of sparrows. Some restoration work at this marsh has been funded through revenues from duck stamp sales.

State-listed Species: