Oyster Farming
Broodstock
Let’s begin with a little biology 101. We grow Eastern Oysters (Crassostrea virginica) native to the North American waters of the Atlantic and Gulf of Mexico. They’re disease-resistant, natural triploids originating from broodstock selectively bred at the Virginia Institute for Marine Sciences (VIMS).
What makes them unique? Triploid oysters have three sets of chromosomes and offer two important advantages in their lifecycle. Because they’re sterile (due to their uneven chromosome number), they don’t expend energy reproducing during
the summer months or lose body weight once they’ve spawned out. They remain firm and plump and grow to market size much faster than a diploid oyster (12-18 vs. 36 to 48 months).
Hatchery
It all begins in our Crocheron, Maryland hatchery with conditioned broodstock selected based on the needs of our customers . Using a scalpel, the hatchery team gently removes and collects the gametes from the oysters.
- Before the gametes are extracted from each oyster, we must determine the sex. Using a pipette, we place a small sample of the gametes on a microscope to determine whether it contains eggs or sperm.
- Sperm from tetraploid males (four sets of chromosomes) is used to fertilize eggs from diploid females (two sets of chromosomes) to create natural triploids . Fertilization takes place within minutes and cell division occurs over the next 24 hours. It’s a natural breeding process.
- As many as 115 million fertilized eggs are introduced to 1,500-gallon tanks in our rearing room.
- The larvae are voracious eaters. And we feed them well. Four to eight times a day with different algae grown in our mass culture room.
- In two to three weeks, the larvae develop an eye-spot, a sign that they are ready to latch on to a substrate.
Nursery
Moved outdoors to our downwelling system at the Fishing Creek or Crocheron hatchery, the eyed-larvae are given ambient water with hatchery grown algae and finely ground oyster shell called micro-cultch. Once settled and attached to this substrate, within 24 hours they undergo metamorphosis and become seed.
When the oysters are about 500 micron or .5 mm, they are moved to a Land-Based upwelling system and fed unaltered ambient water for the first time.
Their energy is focused on shell growth. At about 3 mm (two to four weeks post set), the oysters are graded and moved to baskets in a floating upweller system (FLUPSY).
At about 6 mm (six to eight weeks post set), the oysters are placed in Hexcyl Baskets at our leased sites to continue their growth for approximately 3 months.
Grow-Out
At about 25 mm (5-6 months old), the oysters are placed in various types of gear on one of our leased sites to continue their growth for 6-10 months.
Processing
At 12 to 18 months the oysters are ready for processing, inspection and grading before going to market.
A proprietary wet storage system provides a stable environment to hold oysters post harvest to ensure freshness and quality. Dissolved oxygen is added to increase the oyster’s health and shelf life, while salinity levels can be increased based on the brand to create a unique blend of salty and sweet.
Our Pearlception Oyster Grading Machine, uses 3-D laser image scanning to identify the precise volumetric size of the oyster for packing according to their grade.