Cape Cod Oyster Populations Using Remote Set Technology
by Tracey Crago, WHOI Sea Grant
Off the landing at
Scudder's Lane in Barnstable, Mass., low tide has exposed the usual
cast of characters: periwinkles, oyster drills, quahogs, razor clams,
oysters, and green, mud, hermit and Asian shore crabs.
But these mudflats
also reveal a curiosity not found in any field guide: racks of shallow,
rectangular cages, anchored by steel legs to the muddy bottom. They
sit, adorned with sea lettuce and barnacles, waiting for high tide.
The cages are part
of Barnstable's oyster remote set project, initiated in 1997 as
an experiment. The term "remote set" describes oysters that have
been reared in tanks, attached to material put in the tanks, and
then moved to another location. It is a decades-old technique that
has been used mostly for restoration efforts, for which quantity
is more important than appearance: remote set oysters tend to cluster
together, making them less attractive than the single oysters preferred
by consumers, restaurateurs, and private growers.
shellfish biologist Tom Marcotti refers to remote set as a rough and
dirty way of growing oysters. "You don't have to pamper these oysters,"
he says. "Come harvest time, the harvesters pick up a cluster, break
them up with a screwdriver, keep the three out of 10 that are keepers,
and toss the rest back, many as singles, to grow to the three-inch
Walton (right), MMA hatchery manager, shows an Americorps volunteer
a tank full of juvenile oysters growing on bagged sea clam shells,
as part of the Cape Cod oyster remote set project.
assisted by the Southeastern Massachusetts Aquaculture Center (SEMAC),
got the attention of shellfish constables in other Cape Cod towns,
as well as folks at Barnstable County Cooperative Extension (BCCE)
and Woods Hole Sea Grant (WHSG), who initiated a Cape-wide pilot
project utilizing remote set technology three years ago.
Bill Walton, fisheries
and aquaculture specialist for WHSG and BCCE, along with Diane Murphy,
a Barnstable County marine extension agent, run the program that
was started by Dale Leavitt, former WHSG extension leader. In 2003,
nine of Cape Cod's 15 towns are participating. The project is designed
to increase town oyster populations, establish a suitable habitat
for future populations, and boost the towns' supply of harvestable
Long before cages and
mudflats enter the picture, this story begins in two shellfish hatcheries,
located at opposite ends of the Cape. At the Buzzards Bay hatchery
of the Massachusetts Maritime Academy (MMA), tucked in next to the
Academy's training ship Enterprise on the Cape Cod Canal, manager
Beth Walton oversees the first and most critical phases of the remote
set project: spawning brood stock oysters, raising the larvae, and
transferring the larvae to tanks stocked with cultch (shells, rock,
or other hard substrate) to which the larvae will attach. Ditto
on the other end of the Cape, where Eastham Director of Natural
Resources, Henry Lind, tends to his oysters. Whereas Walton oversees
the spawning and setting phases before turning the oysters over
to the towns for grow-out, Lind keeps his oysters well into the
grow-out phase (usually October), before parceling them out to towns.
At the MMA hatchery,
Beth Walton's trained eye can spot oyster larvae, or "spat," on
clam shell fragments, but she's encountered many a doubting look
from shellfish constables who come to pick up their cultch bags.
She knows they are there, not just because she can see them, but
for what she can't see in the tanks: algae. Oysters eat phytoplankton—and
lots of it, says Walton, who cultures a variety of algae onsite
in the hatchery's greenhouse.
success with remote set oysters helped the town secure grant
funding for 1,000 bags of oysters this year. Each bag contains
thousands of juvenile oysters.
Once the MMA oysters
have set, they are ready to be transported to towns for grow-out.
Oysters at MMA have been grown for Barnstable, Bourne, Brewster,
Dennis, Yarmouth, and Wellfleet. Lind's hatchery in Eastham will
supply oysters to Provincetown and Truro (jointly), Chatham, Eastham,
Conrad Caia, shellfish
constable in Yarmouth, received 100 bags of oysters in early July.
He chose the north side of Grays Beach, inside Chase Garden Creek
off Cape Cod Bay, for his oysters. "It's a high energy zone; the
current rips through there. But I want to see if I can get them
to grow there," he says. The alternative—the south side of Grays
Beach—has its share of problems, from water quality to dermo, an
oyster disease that can wipe out large portions of a population.
"Eventually," says Caia, "I'll put them where the current isn't
so strong. Otherwise, I could be putting the harvesters in danger."
Caia estimates that
since he put the bags in the water, he's spent just a few hours
tending them. The next step, splitting up the bags and placing the
oysters into cages, will take more time: Caia estimates a couple
of days for labor, monitoring, and patrolling the area. He predicts
that the final phase, during cold weather season, will be most labor
intensive: breaking down the cages and planting the oysters off
If the pilot project
succeeds in Yarmouth, Caia would like to continue and possibly expand
the program. "I'd like to try and spark something here. We've got
no intertidal zone and only two areas open to harvesting right now,"
he says. Currently there are no wild oysters in Yarmouth, though
Caia says there was a wild fishery several years ago.
Knowing what to expect
from the project is hard, says Caia, because it's his first time
growing oysters in the wild. But the uncertainty doesn't keep him
from thinking big: he'd like, one day, to produce an oyster reef
that replenishes itself and sustains the recreational fishery in
Yarmouth. "Maybe it's just a pipe dream," he says, "but that's what
I'd like to see."
is pleased that other Cape towns are giving oysters a try. "It's
a fantastic way for towns to bring back the oyster fishery to what
it might have been. When we had our pilot study back in '97, we
put the oysters out, opened the area to harvest, and saw how excited
people were to harvest oysters where they hadn't been before." By
the end of the third growing season, Marcotti says between 90100
percent of the oysters he'd planted were harvestable. "We had so
many oysters to harvest that you could go along and pick the prettiest
ones—whatever hit your fancy that day."
In Eastham, Lind is
encouraged by the feedback he's getting. "This has presented itself
as a way to provide training to folks interested in shellfish and
aquaculture, while testing a concept that the Barnstable County
shellfish officers have been considering for a long time: is it
prudent to have a municipally- or county-operated shellfish hatchery
to supply the Cape towns with seed?" Competition with commercial
shellfish hatcheries was one concern, says Lind. But because most
local hatcheries are producing quahog seed, oysters provide a compromise.
One exception is Aquacultural
Research Corporation (ARC) in Dennis, a private hatchery. But ARC
has partnered with Barnstable's Marcotti, who, this year, received
funding to expand his program. The grant allowed him to purchase
1,000 bags of oysters from ARC, owned and operated by Barnstable
resident Dick Kraus. "Collaboration between the private and public
sectors makes perfect sense to me," he says. "You can contribute
to private economic gain and supply jobs, while at the same time,
the public benefits."
Such partnerships are
possible for other towns, says Walton. "Our hope is that this project
will allow towns to decide if remote set is a method that works
for them, as it has in Barnstable. Ultimately," he says, "towns
may turn to private hatcheries to supply remote set on a larger
scale." Not only is that good for both the public and private sectors,
"it means a lot more oysters for Cape waters."