Mollusks

 

Look Closer! Signs of Sea Life Abound on the Beach

The shores of Fire Island National Seashore are filled with natural treasures. You just need to know where to look.

The ocean and bay shorelines of Fire Island are a place where land and sea meet and can provide clues about what's beyond the water's edge: the habitats and marine life in the nearshore waters of Atlantic Ocean and the Great South Bay. Signs of mollusks, or shellfish, like clams, scallops, and oysters can often be found on Fire Island.

Shellfish Stories: The Great South Bay

Estuaries like the Great South Bay can be one of the most productive habitats on earth, with phytoplankton, eelgrass beds, and salt marshes providing a home for a variety of sea life.

Economically important mollusks include hard-shell clams (Mercenaria mercenaria), soft-shell clams (Mya arenaria), bay scallops (Argopecten irradians), blue mussels (Mytilus edulis) and oysters (Crassostrea virginica). These mollusks are all bivalves. Other bay bivalves include the ribbed mussel (Geukensia demissa) and Morton's egg cockle(Laevicardium mortoni), and the tiny gem shells (Gemma gemma). Univalve mollusks or gastropods in the bay include mud snails (Ilyanassa obsoleta, Littorina littorea) and slipper shells (Crepidula fornicata and C. convexa).

In the mid-nineteenth century, the Great South Bay was known for its Blue Point oysters. Later, from the 1960s to the 1980s, shellfishermen harvested an abundance of hard clams. Overfishing and changes in water quality led to the fall of the Great South Bay's oyster industry in the 1930s and then a steep decline in the hard clam population in the 1980s. Initiatives to improve water quality and restore shellfish populations continue today.

Ocean Shellfish

The open water of the Atlantic Ocean along the southern shore of Fire Island does not provide the protection for organisms that is afforded by the less turbulent, estuarine waters of the bay. However, a number of invertebrates—including mollusks—dwell in the sand on the bottom of the continental shelf along Fire Island.

The economically important surfclam (Spisula solidissima) lives on the ocean side of the island. It is harvested far off-shore, but its shells frequently wash onto the beach. You may even see a flock of gulls fighting over one of these live mollusks on the beach. Other ocean mollusks include the bivalve razor clam (Enis directus) and the univalve conch (Busycotypus canaliculatum).