Northeast Coastal Areas Study
Significant Coastal Habitats
Site 28 (RI)
I. SITE NAME: Block Island
II. LOCATION: Block Island is located in Block Island Sound approximately 10 miles (16 km) south of the Rhode Island mainland and 15 miles (24 ha) northeast of Montauk Point, New York.
TOWN: New Shoreham
COUNTY: Washington
STATE: Rhode Island
USGS 7.5 MIN QUAD: Block Island, RI 41071-25
USGS 30x60 MIN QUAD: Block Island 41071-A1
III. GENERAL BOUNDARY: Block Island is 3.5 miles (6 km) wide and 7 miles (11 km) long, with a land area of 6460 acres (2616 ha). The entire island, including Great Salt Pond, and surrounding nearshore waters is contained within the boundary.
IV. OWNERSHIP/PROTECTED STATUS: Approximately 20% (1,271 acres/515 ha) of Block Island is currently protected through easements and ownership by conservation organizations and local, State, and Federal governments. Of particular interest for additional protection status is the West Beach area, delineated on the accompanying map, which includes those lands south of Sachem Pond along the west shore of the spit to Gunners Hill. The West Beach area consists of a mixed ownership pattern of private, State, Town and The Nature Conservancy properties. Several areas are zoned for conservation by the Town. The U.S. Fish and Wildlife Service owns and manages Block Island National Wildlife Refuge near the northern end of West Beach. The U.S. Marshall has seized the southern end of the West Beach area for violation of Federal drug laws.
V. GENERAL HABITAT DESCRIPTION: Block Island is part of a glacial end moraine of unconsolidated glacial till with elevations ranging from sea level to 211 feet (64 m), with clay, sand and gravel bluffs along the east and south shores that reach 160 feet (49 m). Human development on the Island is generally clustered around the Town center with lesser densities across the rest of the island. The Island was completely cleared of forests by the mid-1700's for pasture and cropland. Unlike other places in New England, the Island's isolation from mainland seed sources and its windy climate have inhibited the regrowth of trees, and Block Island is dominated today by coastal scrub species consisting of shadbush (Amelanchier spp.), bayberry (Myrica pensylvanica), arrowwood (Viburnum spp.), black cherry (Prunus serotina) and rose (Rosa spp.). There is a diversity of coastal habitats, including salt ponds, fresh and saltwater swamps, dune complexes dominated by American beachgrass (Ammophila breviligulata), coastal beaches, marshlands and open fields at the West Beach area. Mean tidal range (at Old Harbor) is 2.9 feet (0.88 m).
VI. SIGNIFICANCE/UNIQUENESS OF AREA: This scenic and relatively unspoiled area is one of the most important migratory bird habitats on the East Coast, and during the autumn the diversity of migrating birds is often spectacular. The island must be viewed as a critical link or stepping stone in the migration of many bird species, particularly raptors and passerines, between southern New England and eastern Long Island and points north and south. Several rare and endangered species may be regularly encountered here, including peregrine falcon (Falco peregrinus), a U.S. Endangered species. The area also provides important nesting habitat for herons, gulls, waterfowl and sandpipers. Other species of regional emphasis or importance occurring here include: American burying beetle (Nicrophorus americanus), a U.S. Endangered species, Block Island meadow vole (Microtus pennsylvanicus provectus), a candidate species for listing under the Endangered Species Act, northern harrier (Circus cyaneus), American oystercatcher (Haematopus palliatus), American bittern (Botaurus lentiginosus), New England blazing-star (Liatris borealis), a candidate species for listing under the U.S. Endangered Species Act, sea-beach knotweed (Polygonum glaucum) and regal fritillary butterfly (Speyeria idalia). A black-crowned night-heron (Nycticorax nycticorax) rookery is established on the southern tip of the West Beach area. There are historical breeding records for piping plover (Charadrius melodus), a U.S. Threatened species, and least tern (Sterna antillarum) in the West Beach area, and it is possible that the Northeastern beach tiger beetle (Cincindela d. dorsalis), a U.S. Threatened species, may occur here. Significant spawning grounds for fish and shellfish are present in the salt ponds and marshes.
VII. THREATS: The Block Island area as a whole is experiencing increased residential development pressure for second and retirement homes. There are risks of both groundwater and surface water pollution from increased or older septic systems, underground storage tanks, runoff and greater use of Great Salt Pond by yachts. Morainal grasslands are vulnerable to habitat succession, particularly by Japanese black pine (Pinus thunbergii), and fragmentation. The dunes and bluffs are highly susceptible to coastal erosion. Several habitats and populations of rare and endangered species are threatened by plant succession, inappropriate land management, insensitive development and the introduction of predators. The currently high and growing densities of herring gulls (Larus argentatus) and great black-backed gulls (L. marinus) on the beach are a potential problem, particularly to other nesting birds. The growing white-tailed deer (Odocoileus virginianus) population may threaten rare plants.
VIII. CONSERVATION CONSIDERATIONS: The Nature Conservancy, the Block Island Conservancy and the Block Island Land Trust have been active in working with landowners throughout Block Island. There is a specific opportunity in the West Beach area to cooperatively protect additional fish and wildlife habitat in the general area of the Block Island National Wildlife Refuge, which, along with other conservation lands, would allow most of the West Beach area to be managed and protected as a larger ecological unit.
Appropriate management of upland areas on Block Island is important for the protection of the valuable wetland resources associated with the ponds, particularly around Great Salt Pond. The interlinked ecological relationships among the species of special emphasis and concern on Block Island provide the opportunity to develop integrated management plans for the island as a whole, which should be considered as a single ecosystem and managed accordingly. The Nature Conservancy has designated Block Island as one of its first bioreserves and is currently developing island-wide management plans in cooperation with the U.S. Fish and Wildlife Service, Town, State and other private conservation groups.
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