Green Clams from Florida’s Nature Coast

by Kevin Folta
Freshly harvested clams.
UF/IFAS Photo by Tyler Jones Freshly harvested clams.

Cedar Key Littleneck Clams (Mercenaria mercenaria) are no different genetically from other Northern Hard Clams. Their claim to fame comes from the warm nurturing waters where they are raised. These particular clams are recognized for their firm texture, sweet-salty flavor, high protein, and low fat. They are high in vitamins, minerals, and omega-3-fatty acids. They are served steamed, roasted, grilled, or on the half shell. Clams also impart environmental benefits, making clam farming a clean-and-green enterprise.

But these clams are not just delicious — they have a story. They saved a town, and are the foundation of a new industry.

The year 1994 marked the end of an era — the end of net fishing off the island of Cedar Key, Florida. Generations of net anglers had sustained both industry and family alike, yet new rules threatened the economic sustainability of the tiny fishing town.

Cedar Key is one of Florida’s best-kept secrets. When we dream of the Sunshine State thoughts gravitate to Mickey Mouse and oranges, coastal beaches, and kayaking serene swamps. But about two hours north of Tampa on the Gulf side resides a region that is a throwback in time. This region of shallow coastline is home to nature unadulterated, with miles of weedy ocean flats that span as far as the eye can see. The waters teem with life, featuring abundant birds, fish, and shelled critters.

The end of gill-net fishing brought crisis, but simultaneously spawned opportunity. Net fishermen retooled into clam farmers, using Cedar Key’s reefs as a foundation of new industry. The State of Florida, along with experts from the University of Florida/IFAS assisted in the transition. Now the tiny island village is one of the nation’s leading clam producers — an industry generating over $30 million a year.

Clam fishermen harvesting bags of mature clams
UF/IFAS Photo by Tyler Jones Clam fishermen harvesting bags of mature clams off the coast of Cedar Key, Florida.

The waters off Cedar Key are especially well-suited for clam farming. The area is fed by active currents and fresh-water rivers and streams that deliver abundant nutrients to the adjacent reefs. Along with the warm subtropical temperatures, these conditions create a perfect environment for clam aquaculture. Clam farmers are leased a 2.5 acre space on the shallow ocean floor to raise their crop.

“People in Cedar Key don’t consider themselves aquaculturists – they’re clammers. We’re into our second generation of clam farming families, with a third on its way. It’s a way of life now, and if we keep doing the right things, I think it is here to stay,” said Dr. Leslie Sturmer, University of Florida/IFAS Aquaculture Extension Agent.

How do you farm clams? Like any livestock, parent clams are carefully chosen. They are selected for fast growth and shell patterns, and then mated. Young clams are raised as “seed” in an inland hatchery. The young clams are grown to 1.5-2.0 cm in diameter and are then transferred to large polyester net bags that are carefully placed into the cradle of the sea. The clams develop in the sun-warmed waters off Cedar Key, filter-feeding the abundant phytoplankton and nutrients wafting in the sea water. Twelve to twenty-four months later they are fully grown, and ripe for harvest.

Clam farming has an important green edge. The bottom-dwelling clams are filter feeders. Each clam filters hundreds of gallons of water every day, assimilating nitrogen flowing from onshore, and clarifying the water from microorganisms. They require no inputs like fertilizers or other production chemistries. The Cedar Key shore has everything they need. Clams remain one of the most sustainable seafoods.

Cedar Key Clams are currently served in over 70% of Florida seafood restaurants and are sold nationwide through a rapid distribution system.
Freshly harvested clams.
UF/IFAS Photo by Tyler Jones Freshly harvested clams.

The future looks bright for Florida clamming. Another species called the Sunray Venus Clam is native to Florida. It is larger and has a flavor different from the traditional hardshell clam, but is not yet adapted for aquaculture. However, scientists are treating it like any crop, working on breeding the species to work well in the aquaculture system.

When net fishing ended in the 1990s a way of life ended. However, innovation and hard work, with a pinch of science, brought about a new opportunity that brings a taste of a sustainable seafood resource to tables all over the country.

Harvesting a bag of Sunray Venus clams
UF/IFAS Photo by Tyler Jones Leslie Sturmer (left) and Reggie Markham (right) harvest a bag of Sunray Venus clams just offshore of Cedar Key, Florida.