During the summer when our bay waters begin to warm up to the perfect temperature, usually around 70 degrees Fahrenheit, the reproductive organ (gonad) of a mature Bay Scallop (Argopecten Irradians) begins to fill with both egg and sperm. Yes, the Bay Scallop is a true hermaphrodite, unlike clams and oysters which are protandric hermaphrodites, meaning they often mature as males then switch to females later in life.
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Once the temperature reaches optimal spawning conditions, it triggers mature scallops to release millions of eggs and sperm (gametes) into the water column hoping to meet up with other scallop gametes to form a scallop larva. Once the larvae have formed they will float freely throughout the water column along with billions and billions of other microscopic plankton bits. At this stage about one in a million scallop larvae will survive.
After several weeks and lucky enough not to be consumed by other filter feeding organisms, the scallop larvae will metamorphose and develop a calcium carbonate shell enabling it to sink to the bottom of the bay.
At this stage of the scallop's life, habitat plays a vital role in the survival of this species. The young scallop will require a safe haven such as an eelgrass bed to shelter itself from predators such as crabs and sea stars. It is here the scallop will stay for the remainder of the season and into the fall, nourishing water through its gills, extracting both oxygen and nutrients in the form of plankton.
The feeding rate of a bay scallop is astounding and enables the scallop to grow quite rapidly, reaching close to 40 millimeters by the winter.
As spring approaches the following year, an abundance of phytoplankton blooms occur around March and April. These blooms allow these now reproductively mature scallops to filter in the necessary nutrients to properly develop their gonads for the release of the next generation of scallops into our waters.
Once these year-old scallops have spawned in June, July, and August, they filter feed and accumulate the necessary energy reserves needed to sustain themselves during the cold winter months. This energy reserve is in the form of sugars such as glycogen and gives the bay scallop's adductor muscle its sweet taste during the harvest season (November to March).
At this time the scallops are 65 to 70 millimeters in size. Since the life cycle of a bay scallop is only 18 to 22 months, those scallops not harvested will expire by the following spring only spawning once in their lifetime.
Visit the South Fork Natural History Museum (SoFo) and its marine touch-tank to learn more about these magnificent creatures. Call SoFo at 631-537-9735 for more information.
Frank Quevedo is the executive director of the South Fork Natural History Museum. Located in Bridgehampton, SoFo is the only state-of-the-art natural history museum on the South Fork. Check it out at sofo.org.