Fire Island forms an interface between two distinctly different marine environments. The Atlantic Ocean borders the southern exposure of Fire Island and the Great South Bay and other estuarine environments border its northern exposure.

The estuary is one of the most productive habitats on earth, with its phytoplankton, eelgrass beds and salt marshes. In the Great South Bay, that means home for a variety of sea life. Detritus from the marshes is washed into the bay, where it is used as food by many organisms, including mollusks and crustaceans.

The sandy beaches within the intertidal zone support algae, bacteria, and a few species of worms and small crustaceans.

Crustaceans include crabs, shrimp, copepods, isopods, and other invertebrates with a hard exoskeleton.  

One economically important shellfish in the waters surrounding Fire Island is the blue crab (Callinectus sapidus). Other crabs include the lady crab (Ovalipes ocellatus), green crab (Carcinus maenas), and spider crab (Libinia emarginata).

Ghost crabs (Ocypode sp.) dig their burrows on the beach, while mole crabs (Emerita talpoida) live in the swash zone along the edge of the ocean. The horseshoe crab is not a crustacean, but in a class of its own, more closely related to spiders.

Other crustaceans include the sand shrimp (Crangon septemspinos), and grass shrimp (Palaemonetes vulgaris).    

For More Information

A series of Science Synthesis Papers was published in 2005 to support the preparation of a General Management Plan for Fire Island National Seashore.

• Conservation and Management of the Living Marine Resources of Fire Island National Seashore
  (Fire Island National Seashore Science Synthesis Paper) by David O. Conover, Robert Cerrato, and William Wise, Stony Brook University, December 2005.

Additional recent studies that include inventories of crustaceans near Fire Island include:

• Intertidal Wetland and Estuarine Finfish Survey of the Backbays, April 2002
  U. S. Army Corps of Engineers 
  As a part of the U.S. Army Corps of Engineers (USACE) comprehensive study to identify, evaluate, and recommend longterm measures for hurricane storm damage reduction for the south shore of Long Island, New York from Fire Island Inlet to Montauk Point (FIMP), a number of environmental studies have been completed.