OYSTER AQUACULTURE
An Oyster spends almost its entire life stuck in a single spot. It opens its shell only to filter food from the water. This is its only movement… except during the first three weeks of life. At this time, newly hatched oysters (known as “larvae”) are very small and can swim freely in the water column. As they grow and gain new abilities, the larvae pass through specific stages of the lifecycle.
Once an oyster egg is fertilized and its cells begin to divide, it is called an EMBRYO. This is the first stage of the oyster lifecycle. In the TROCHOPHORE stage, hair-like structures called “cilia” develop allowing it to move through the water column. Next, during the D-HINGE VELIGER stage, two shells (or “bi-valves”) and the “velum”— an organ for movement and eating—develop.
In the VELIGER stage, a hinge between the two shells, known as the “umbo,” develops from the straight side of the D-Hinge. Veligers continue to use their velum to swim freely in the water column. After about 2½ weeks, the free-swimming larval oyster develops a foot (or “ped”) and prepares to permanently attach itself to a hard surface—usually an old oyster shell. This is called the PEDIVELIGER stage of its lifecycle. Once the Pediveliger is permanently attached, it’s known as a SPAT. From this permanent spot, the baby Spat filters algae from the water and grows quickly.
After a couple of months, the Spat grows to about the size of a quarter and reaches the JUVENILE stage. During the Juvenile stage, the oyster continues to grow and remains in this stage until it reaches adulthood. In the ADULT stage, the oyster is able to reproduce and the lifecycle continues in the next generation. Interestingly, most oysters begin adulthood as males and become females later in life. Some can even change gender from one year to the next!
OYSTER CULTIVATION PROCESS:
The Life of an Oyster
SEED ARRIVAL
By starting to grow oysters on the weekends, the family farm began by the Shelleys and has expanded to hundreds of cages and thousands of oysters.
The Shelleys purchase baby oyster seeds from the local hatchery every few months. The oyster seed is approximately 3 millimeters in length and about an eight of an inch long when it arrives on the farm. The purchase of 250,000 oysters weight about a half of a pound when bought, and in a matter of 12 to 18 months will cover an acre of the farm and weight over 25,000 pounds.
Placing 1,200 oyster seeds in each 2-millimeter mesh bags, the oyster farmers secure the bags with PVC pipe. The tiny oyster babies will remain in this protected environment inside a cage until they are mature and ready to sell. The cages are suspended in rows of cages right below the water surface. This keeps the oysters out of the muck, so they can feed and grow on nutrient-rich water while avoiding being smothered by sedimentation. Most importantly, these buoyant cages keep the baby oysters away from their biggest predator, the blue crab!
Over the next few months, the oystermen watch as the baby oysters double in size. Truly amazing!
GRADING, TUMBLING, SORTING & SPLITTING
Oysters, like any animal, grow at different rates. Therefore, skilled oystermen must separate the fast growers from the slow growers.
This is done because the varying sizes of the oysters in the cages create a compact mass (or cluster of oyster) with very little nooks and crannies for water to seep in and flow over the oysters. This compaction slows the rate of growth, so the farmers separate them out to maximize the rate of water flow.
The Shelleys monitor the oysters weekly in their floating cages to determine when they need to be removed and run through the oyster tumbler, a specially-designed machine that grades the oysters according to size, washes the oysters, and chips the beaks off the edge of the shell to give the oyster that wonderful “cupped” appearance over time. While tumbling, instead of replacing the oysters in the same bag, they “split” the volume of oysters per bag in half, thereby increasing the amount of water flow and decreasing the competition for nutrients within the cage.
MATURING & HARVESTING
Twelve to eighteen months from when the Shelleys receive the baby oysters, the oysters are ready to harvest. At this point, the Shelley Farms crew pulls up the cages from the water and brings the grow-out bags back to the oyster barge.
Here they spend many hours emptying the bags, sorting the oysters for size and quality. Essentially, they are searching for the “perfect” oyster, specifically looking for the ones that have a deep, round “cup” and measures at three inches in length.
Washing these oysters with the same sea water that they have been growing in all this time, the farmers count and box up the oysters. They then haul the oysters from the farm to the dock where trucks are awaiting shipment. It is a labor-intensive process but one that ensures that only the best oysters are taken to market.
The Shelley Farms crew works five days a week, harvesting to ensure the customer has the freshest oyster possible.
DELIVERY
Once the market-size oysters arrive to the dock, the Shelley Farms premium Louisiana oysters are shipped to restaurants in refrigerated trucks within 24 hours of harvest.
Similarly, if the oysters are being shipped direct, they are packed in Styrofoam coolers with frozen gel pack inserts and shipped overnight to your door.