Nantucket Sound is the body of water between Cape Cod and the islands of Martha’s Vineyard and Nantucket. It is situated at a confluence of the cold Labrador Currents and the warm Gulf Stream. This convergence creates a unique coastal habitat, representing the southern range for Northern Atlantic species and the northern range for Mid-Atlantic species. Nantucket Sound is characterized by remarkable richness of biological diversity, with habitats ranging from open sea to tidal flats, salt marshes, and estuaries. The complex networks of habitat utilization and species competition within the Sound remain an area for significant scientific research.
The Sound includes 750 square miles of water and seabed between the Cape and Islands and possesses significant marine habitat for a diversity of ecologically and economically important species. It has particular significance for several federally-protected species of wildlife and a variety of commercially and recreationally valuable fisheries. A 2003 report prepared at the request of U.S. Representative William Delahunt (MA 10th District) by the Provincetown Center for Coastal Studies found that the Sound “contains significant ecological, commercial and recreational resources that have been at the heart of several past nominations for enhanced environmental protection and conservation policies within the region.”
Nantucket Sound and the waters surrounding the Cape and Islands are famous for their natural beauty and abundant, diverse, and unique wildlife. The Sound is also renowned for recreational boating and fishing, and contributes to drawing over six million visitors annually to Cape Cod and the islands of Nantucket and Martha’s Vineyard. It is a source of livelihood for fishermen, and a source of solace, relaxation, and recreation for millions of visitors. Nantucket Sound is essential to our regional economy precisely because of its natural appeal.
“The ocean and bays that surround us are perhaps our town’s most important and defining natural resource and it is these unspoiled waters that are the very essence of Cape Cod. We are a community of people drawn to the sea as sightseers, swimmers, sailors, fishermen or beachcombers. We are thankful for, and jealously seek to protect, the open space of the ocean around us. There is no other part of our community that offers more sweeping vistas, wildlife diversity and a place of refuge from the steady march of development.” — Barnstable Land Trust
State vs. Federal Jurisdiction
The waters of Nantucket Sound that go from the shoreline of Cape Cod and the Islands out to three miles belong to the Commonwealth of Massachusetts. The center of the Sound, however, is under federal jurisdiction. Nantucket Sound’s jurisdictional boundaries delineated by the U.S. Supreme Court resulted in this section of federally owned waters surrounded by state waters. In United States v. Maine (1975), states have jurisdiction over all submerged lands within the three-geographical mile zone, and the U.S. has title to the seabed more than three miles from shore.
This jurisdictional delineation, however, does not apply to bodies of water such as Cape Cod Bay. Because the Bay has only one outlet to a single larger body of water and a borderline can be drawn between two points on either side of the opening, the body of water is “contained,” and the three-mile ruling does not apply.
A Sound, on the other hand, is a coastal waterway that has two or more outlets and cannot be contained by a single borderline, therefore, state waters end at the three-mile boundary.
Federal Waters in the Center of Nantucket Sound
Federal Lease Area