Crop of the Bay: Homegrown Oysters
by Audrey Thomasson
Mark Boswell is a real maverick. Most weekdays, he’s a salesman for an Ohio-based company covering a region that spans the northeast to southern states. On Sundays he steps into the role of interim preacher at Maple Grove Baptist Church in Foxwells.
And in between, he’s an oyster farmer with a start-up business operating as Fleet’s Island Oyster Company.
He had no experience as a waterman when he started the venture 18 months ago. But when the opportunity came up to move into his family home place in Foxwells near Windmill Point, he decided to follow the tradition of his grandfather, and the great-grandfathers before him, and become a waterman.
“I came back here to learn more about what my grandfather did.”
It was his grandparents’ stories of life as a waterman that filled a young boy’s head with romantic adventure and big dreams he never forgot.
“My grandmother said Little Bay had so many workboats you could walk across them.”
Boswell tells the story of the day his grandpa caught so many fish in his pound nets, he sent his wife into town to hire additional men to help bring in the catch.
In those days, being an oysterman meant taking the boat out and searching for oyster beds by scratching the river bottom. Oystering was more plentiful and the waters were cleaner. But it was still a hit-or-miss proposition.
“Watermen in those days were hunter/gatherers. Today, it’s oyster farming and we’re harvesters,” Boswell explains. He calls today’s oystermen “...the last of the cowboys of the water...a dying breed locking horns with Mother Nature.”
Oyster farms rely on aquaculture—starting oysters under controlled conditions in marine environments and underwater habitats.
That’s exactly where Boswell started—and you can too.
|1. At the aquaculture system at Oyster Seed Holding in Mathews, the cycle of life begins from four varieties of brood stock oysters.|
|2. Oystermama Judy Ambrose shows commercial oysterman Mark Boswell how the feed tanks work. Algae must be grown to feed growing oyster larvae and seed. It’s a water forest of 80 120-gallon tanks.|
|3. Larvae will double in size every two to three days during the first life cycle.|
|4. At the beginning of the second stage of life, spats attach to shell surfaces as they continue forming shells that are now beginning to harden.|
|5. At 2 millimeters to 1/4-inch, spats are ready for an oyster nursery. The bag contains some 500,000 spats for Boswell’s Fleet’s Island Oyster Company.|
|6. At Boswell’s commercial facility, he divides up his spats into buckets which are submerged into a tank fed from the creek. Water is continually pumped through the tanks, which he cleans every couple of days.|
|7. As they grow, Boswell transfers them to river cages at his dock...|
|8. ...then into cages located in 400 leased acres of river.|
|9. Backyard growers can purchase fertile or sterile oyster seeds to grow in their floats.|
OSH’s brood stock manager, Judy Ambrose, is known to all as ‘Oystermama.’ She takes care of the brood stock, making them fat and happy, keeping conditions exactly right for hibernation, and then, when the time is right—which just happens to start around Valentine’s Day, go figure—she tricks their environment into spring and they start spawning—upwards of 1.5 billion larvae a year.
“You can see the cell division in about 20 minutes,” she says with pride. “And they’ll double in size every two to three days.” What looks like a splash of oily water is oyster larvae. They are nurtured in large tanks until they metamorphose into spats that cling to shells and continue developing their own shells as oyster seeds.
I won’t overwhelm you with details of the whole “ancestry.com of oysters” thing and the breeding process. Or drown you in details about the daily care of the brood stock and larvae including operating a high density food hatchery that feeds millions, daily cleaning and sterilization, and the critical process of controlling water temperature to “change” the seasons.
In a nutshell, Oystermama’s job involves a highly scientific process beyond most of our IQs. However—and here’s the part the general population can grasp—she also incorporates a few unscientific, but proven methods.
Prior to setting up the lab for spawning, she fills the place with music to put the moms- and pops-to-be in the right mood. The first week they hear classical works from their underwater cages. Then it’s dance time—a little salsa, maybe some Harry Connick Jr. And finally, what oyster could resist spawning when they hear Marvin Gaye’s “Let’s Get it On.”
Perched above the tanks is the image of a fertility goddess. You get the picture. Nothing is left to chance.
To the point: Scientists and growers want to reproduce stronger oysters at a faster rate. This is accomplished in a controlled environment by reconfiguring the oyster’s DNA (removing one of the four sets of chromosomes) making a ‘triploid’ oyster—one that is sterile. Triploids are more robust and resistant to disease, giving them a 50% higher survival rate. Also, they grow to maturity in just 18 to 24 months rather than three years. But for backyard growers, they also provide fertile oysters who will keep the process going under the dock.
This is all good news for the Chesapeake Bay, since oysters are the primary filtration system to clean the water of contaminants pouring in from sewers, farms and any place people and animals happen to occupy.
One mature oyster will clean 50 gallons of water in a day. Put a couple billion oysters in the water each year, and maybe in a few generations the bay will resemble the place Captain John Smith saw when he explored the area 400 years ago. At that time, oyster reefs were so great they crested the water’s surface and filtered the entire bay in a day.
Virginia and Maryland encourage people with water access to grow oysters. Maryland even offers tax exemptions. Those living in Virginia will have to be content with the knowledge they are saving our little corner of the world.
Local growers, including her own company, Oystermama’s Baybies, offer 1,000 oyster seeds for about $25. They sell start-up bags and will give you advice on how to hang it, when to flip it over, and when to graduate to the next size bag or cage as the oysters grow.
Before you yell “OMG, they’re all crammed together in one bag!” let me explain. The oyster life cycle consists of two stages: the first being as free swimming plankton which lasts 2 to 3 weeks. This is followed by a “couch potato” stage lasting the remainder of its life. In their time beneath your dock they will be just filtering water and maybe making the occasional pearl. So make them comfortable for the next 18 months—until you start eating them.
“There are a variety of cages, reefs, bags, floats, tubes, and tar slides” being used to raise oysters, according to Oystermama. They can cost anywhere from $15 for a bag up to $75 for a float. Each comes with its own set of instructions.
Just make sure their new accommodation is tied to home base or they’ll be floating away with the tide. Keep them off the river bottom so they don’t smother, but submerged so that they won’t freeze in winter. “Ice is an insulator, so don’t knock it off the shells,” she advises.
Circle C Oyster Ranchers Association in Maryland suggests you choose a location where there is a good flow of brackish water. The oysters’ food comes to them on the tide and they require constant feeding. The side of the float should face into the waves and should be clear of pilings.
Sea nettles and barnacles around your dock are good indicators that the salinity is right for oysters, but there is a breed for low salinity water, too. If you can leave your boat tied up to the dock year round, you probably also have the right wave energy and water depth.
Now, all you need to do is watch your oysters grow and give them a little attention.
Yes, blue crabs love oysters. If one gets inside the oyster bag, it can eat an average of 40 oysters over the summer. Remove any that you find. Other crabs are not harmful to oysters. To identify a blue crab, the back legs are formed with little paddles on the ends.
Whenever the mesh bag or float starts getting plugged up with unwanted organisms, both plant and animal, flip it over. You may have to do this every three to five weeks. Knock off barnacles as soon as you see them.
Although oysters can withstand being out of the water for a while during the cleaning process—up to 12 hours or so—they need to be underwater the rest of the time. Expect a loss rate of 10 to 15% over the entire process.
When the shells reach about three inches, they are ready for harvesting.
According to Boswell, oysters are like grapes; they take on the flavors of their surroundings. But if you don’t like shellfish, raise them for their contribution to the planet. Your grandchildren will be glad you did.
Mark Boswell considers himself one of the last of the cowboys. But rather than herding cattle, this buckaroo is rustling oysters. A million of them. And raising them on 400 acres of river leased from the state. At the same time, his oyster farming venture is an important benefit to the environment because oysters filter contaminats from the water.
If Boswell can do it, anyone can, he says. While you probably don’t want to start a commercial enterprise, it’s easy to start up a homegrown crop.