Return to resources for:
- Coastal Decision Makers
- Educators and Students
Shellfish Aquaculture in Massachusetts
(Click here to view this document
as a PDF file.)
Shellfish aquaculture in Massachusetts is thriving! Though centuries
old, the practice of farming shellfish is a fairly recent undertaking
in the United States -- within the last 150 years.
In Massachusetts, shellfish aquaculture can be divided into two
categories: public and private. Public aquaculture, also known as
community or municipal aquaculture, focuses on local restocking
and/or restoration efforts in areas that are or once were productive
shellfishing areas. Such programs generally fall under the auspices
of town shellfish constables. Municipal aquaculture programs raise
clams, oysters, and/or scallops to a size that they can be released
into the wild with a reduced risk of mortality from predation. At
the appropriate size threshold, the shellfish are seeded into productive
fishing areas to support local wild harvests, both commercial and
Private aquaculture involves licensing tracts of marine intertidal
and subtidal areas for private use to grow a variety of commercial
shellfish species, including quahogs and oysters. Local shellfish
hatchery and nursery businesses often support public and private
aquaculture operations and municipal restoration programs.
Nursery trays are commonly used during the
early stages of shellfish culture. Shown here, trays holding seed
quahogs in Blackfish Creek, Wellfleet. Photo by Dale Leavitt.
Production of farmed shellfish in Massachusetts has been expanding
steadily over the past 10 years as the number of towns, farmers,
and areas licensed for culture have increased. Of the $4.6 million
total value for cultured shellfish production in Massachusetts in
1996, quahogs account for the vast majority, at $3.8 million, while
oysters make up the difference, at $0.8 million. Since 1996, the
number of private aquaculture permits for shellfish culture has
increased from about 250 to over 300, while the areas privately
licensed for culture has increased from 600 acres to over 1,000
acres. Greater than 95 percent of this culture area is located on
intertidal and subtidal flats within two counties of southeastern
Massachusetts: Barnstable (Cape Cod), and Dukes (Martha’s
While shellfish aquaculture is experiencing significant growth,
commercial harvest of wild quahogs and oysters in Massachusetts
has remained fairly flat, hovering at the $5.5 million mark for
the past ten years. Of this, Cape Cod harvests account for approximately
$3.1 million, while Martha’s Vineyard harvests provide an
additional $0.55 million, together accounting for nearly two-thirds
of the total harvest in Massachusetts. In terms of the recreational
fishery for quahogs and oysters, figures are more difficult to come
by, mostly because recreational harvesters do not have to report
their catch -- other than an estimate -- when renewing their licenses.
Despite the lack of harvest data, recreational quahog and oyster
fisheries are a very important component to the way of life in southeastern
Town shellfish departments on Cape Cod and Martha’s Vineyard
are committed to public aquaculture of hard clams and other shellfish
species for the purpose of stocking shellfish for wild harvest.
In 1999, with funding from the Massachusetts Division of Marine
Fisheries, distributed by Barnstable County, all fifteen towns on
Cape Cod collectively purchased 20 million juvenile quahog seed
from commercial hatcheries as part of their municipal restocking
On Martha’s Vineyard, the Martha’s Vineyard Shellfish
Group (MVSG), a consortium
of Island towns dedicated to producing shellfish seed in a hatchery,
provided 11 million quahog seed, four million oyster seed, and six
million juvenile bay scallops to the six island towns in the program.
These juvenile bivalves will be released into the wild fishery after
nursery culture within each town’s municipal shellfish nursery
program. In addition, the MVSG provided one million seed oysters
to private growers on the Island that are participating in a fishermen’s
retraining program administered by the MVSG.
Current Culture Practices
Massachusetts has two shellfish hatcheries that pro-duce a wide
variety of seed shellfish, including American oysters, quahogs,
bay scallops, soft shell clams, and surf clams. One hatchery is
a commercial enterprise, Aquaculture Research Corporation (ARC),
located in Dennis, MA. ARC has been at the forefront of shellfish
hatchery technology and production for over thirty years. MVSG is
the second Massachusetts hatchery and has been operational since
1978. Unlike a commercial hatchery, the goal of MVSG is to supply
the public shellfish propagation programs on the island with quahogs,
oysters, and bay scallops. Both hatcheries are proven success stories.
The nursery stage of both quahog and oyster farming involves the
use of trays: a bottom tray system on Cape Cod, and a raft-based
tray system on Martha’s Vineyard. In both methods, growers
purchase small seed (1-3mm) and plant it into shallow trays (4–8
inches deep and usually 32-square feet in size) in late spring (June).
Private quahog growers harvest the seed stock in October, or once
quahogs reach approximately 15mm in size. They are then planted
under netting for the final grow-out stage. Town shellfish restocking
programs take a different approach: seed remains in nursery trays
throughout the winter until it reaches approximately 25mm in size.
This generally occurs by spring, at which point the seed is planted
directly into the wild.
A recent WHOI Sea Grant Extension Program/Cape Cod Cooperative
Extension effort involves assisting with the development of upwelling
nurseries in Massachusetts. Upweller technology allows growers to
purchase smaller, less expensive seed and grow it in a protected
environment (the upweller) until it is ready for the field nursery
(late summer) or direct grow-out planting (fall). For the final
grow-out stage, most growers plant on the bottom and cover the crop
with a fine mesh net to exclude surface predators.