Jones Beach Island: A Barrier in Motion

Jones Beach Island belongs to one of the most dynamic landform systems on the Atlantic Coast. It is part of the outer barrier, a chain of long, narrow islands running the entire length of Long Island's southern shore, separating the open Atlantic Ocean from the sheltered bays and wetlands between the islands and the mainland. Jones Beach State Park alone runs about six and a half miles along Jones Beach Island, which lies between South Oyster Bay and Great South Bay to the north and the ocean to the south.

Barrier islands like this one are not static. They are built from sand deposited by wave action and longshore currents, and they migrate slowly westward over time as waves erode their eastern ends and deposit sand on their western ends. The entire outer barrier of Long Island, including Fire Island, Jones Beach, and Westhampton, is drifting in this way, a geological process that no amount of engineering can entirely stop.

The natural vegetation of a barrier island is a sparse community of beach grasses and low shrubs adapted to salt spray, shifting sand, and periodic flooding. Almost all of that natural vegetation on Jones Beach Island was buried when Moses built up the island in nineteen twenty eight. The planted beach grass holding the dunes together today is doing deliberately what barrier island plants once did on their own, before the dredges and the construction crews and the parkways arrived and made this sliver of sand one of the busiest public beaches in the world.