The hard clam production process consists of three consecutive stages—hatchery, nursery, and growout to a marketable size.
Photo by University of Florida IFAS.
Clam farming begins in the hatchery with production of seed. Adult clams are induced to spawn by manipulating water temperatures.
Photo by Tom Smoyer, HBOI.
In the hatchery, larval clams are reared under controlled conditions in large tanks supplied with filtered seawater.
Photo by Sean Dowie.
During the hatchery phase, cultured marine microalgae are fed at increasing densities to larvae and post-set clams.
Photo by Leslie Sturmer.
Post-set clams are maintained in the hatchery until they reach about 1 mm. Over 100,000 seed are held in this downweller.
Photo by Eric Zamora.
The nursery is an intermediate step, where hatchery-produced seed are reared under semi-controlled conditions in land-based systems, such as these raceways.
Photo by Eric Zamora.
Another method of land-based nursery culture is the upweller system; some designs place the wellers, or cylinders, in the water.
Photo by Leslie Sturmer.
Clams are grown to market-size on coastal submerged lands leased from the State of Florida.
Photo by Florida Department of Agriculture and Consumer Services.
When clam seed reach about 1/4”, they are stocked in polyester mesh bags and staked to the lease bottom for growout.
Photo by Leslie Sturmer.
After 15-18 months depending on season planted, littleneck-sized clams are harvested by pulling the bags off the bottom.
Photo by University of Florida IFAS.
Harvested clams are delivered to a certified shellfish wholesaler where they are prepared for processing and shipping to markets across the country.
Photo by Eric Zamora.
Previous
Next

About the Industry

Molluscan shellfish aquaculture is the largest food-use aquaculture industry in Florida. Hard clams Mercenaria mercenaria dominate the industry. Other shellfish produced in the state include oysters Crassostrea virginica and sunray venus clams Macrocallista nimbosa. Production occurs across a total of 720 shellfish leases (average lease size is just under 2 acres) in 16 coastal counties. Most leases are found along the Florida Panhandle and Big Bend, specifically in Levy, Franklin, Wakulla, and Dixie counties. At the end of 2019, there were 336 certified producers with 56% producing hard clams, 16% producing oysters, and 28% producing both (FDACS internal data, 2019). The naturally warm temperatures and high productivity levels of Florida waters create a superb environment for growing mollusks. Growth is almost year-round, resulting in shorter crop times than realized in other states. In addition, Florida shellfish growers plant seed year-round, enabling them to harvest continuously. As a result, shellfish aquaculture production has increased rapidly over the past 30 years.

Status of the Industry

Background

Shellfish aquaculture is a relatively new industry in the state. The industry traces its beginnings to the Indian River Lagoon along the east-central coast. During the 1980s, unreliable sets of hard clams prompted harvesters to investigate aquaculture as an alternative to fishing natural stocks. This transition was facilitated by research conducted at Harbor Branch Oceanographic Institution, in which traditional culture techniques used in the Northeast were modified for Florida’s subtropical, subtidal conditions. Expanding employment opportunities for the Florida fishing industry affected by increasing regulations was the focus of federally funded retraining programs conducted during the 1990s. These community-based programs provided the infrastructure for introducing shellfish aquaculture as a means of economic growth for rural communities. Over 350 program graduates were placed onto shellfish aquaculture leases, the first leases approved along the Gulf of Mexico coast. More recently, the oyster fishery failures in 2012-14 resulted in a renewed interest in oyster culture. The establishment of water column leases has created a new opportunity for off-bottom oyster production.

Shellfish Culture Methods

Shellfish farming consists of three consecutive biological or cultural stages: production of small seed in a hatchery, rearing of larger seed for field planting in a land-based nursery, and growout on an open-water lease to a marketable size.

Take a Look at Florida Clam Farming

Changing Seas – Farming the Seas, Part 1
Produced by WPBT2 Miami

Cedar Key Clams: Fishermen Farming the Sea
Produced by UF IFAS