Scallops live about one year before either dying off naturally or being eaten by humans, crabs, octopuses, or a variety of shell-crushing fish. They spawn primarily in the fall. After about a two-week period as plankton, larvae develop a small shell and settle onto seagrass blades. They continue to grow while attached to the grass blades by a mass of silk-like filaments called a byssus. They later fall from the grass blades and become free swimmers. Unlike oysters and clams, scallops are active swimmers. They click their shells together, forcing expelled water to propel them rapidly. Scallops are simultaneous hermaphrodites, able to spawn as either males or females, and are very fertile. A single scallop can produce more than one million eggs per spawn.
To monitor bay scallop populations in the state and maintain a plentiful breeding population, the Florida Fish and Wildlife Conservation Commission (FWC) annually reviews the status of the scallop stock. In 2002, FWC reopened an area between the mouth of the Suwannee River and the Pasco/Hernando county line. This area had been closed for seven years due to the limited number of scallops in that region.
It is believed that the comeback may be partly the result of a restoration program begun by scallop researchers at the University of South Florida, Florida Sea Grant, and FWC through its Fish and Wildlife Research Institute (FWRI). Early work funded by Florida Sea Grant determined the feasibility of aquaculturing the bay scallop both as a commercial fishery, and for replenishing depleted natural stocks. The funding allowed researchers to expand a scallop hatchery and nursery, which in turn provided enough scallop seed to test hatchery-release technology.
Early restocking efforts examined what was more effective, cage or free-planting cultured scallops. Scallops are known to be “catastrophic spawners” — when one spawns, they all do. A number of adult, spawning scallops were placed in cages on bay bottom where healthy populations previously existed. It was found that hatchery-reared scallops held in close proximity appeared to have an increased chance of successfully reproducing over natural scallops that are sparsely distributed. Recent studies by researchers, including scientists from Mote Marine Laboratory and FWRI, have shown that adult populations may quickly rebound in some SW Florida locations when late-stage hatchery-reared larvae are introduced. Future genetic studies are expected to evaluate the long-term effectiveness of using larvae to increase scallop populations.