May 2022, ScientificAmerican.com 55research and development at the company, ushered me
into the hatchery, a moist, cavernous space that reeked
of the sea. White first met Mook while she was a re -
search scientist at Bigelow Laboratory for Ocean Sci-
ences in East Boothbay, Maine, and her knowledge of
bivalves is exhaustive. Mook’s oysters, she says, are bred
for certain traits—size, shape, disease resistance—in
shellfish labs in Virginia and New Jersey and shipped
to Mook’s as brood stock. “Some are male, some are
female, but you can’t tell which without opening them,
and that would kill them,” she says.
Workers need to wait for the oysters to declare their
own sex: both females and males clap their shells before
a spawning session, during which females release a
cloud of as many as 20 million eggs and males emit a
stream of sperm. Technicians carefully combine the eggs
and sperm in small white bowls to begin a process of in
vitro fertilization. The resulting embryos are transferred
to tanks holding 3,000 to 6,000 liters of water, which is
gradually warmed to optimize growth. “We check them
under a microscope every day,” White says. “We can see
the cells divide, and in 24 hours, they have a shell.”
In about two weeks the oysters form a pigmented eye-
spot (interestingly, mature oysters have eyes all over their
bodies), a sign that they are approaching the pediveliger
stage, when they will sprout the bivalve equivalent of a
foot. White pulled out trays of ground oyster shell on
which tiny oysters “set” this foot, glomming on to the
hard surface with a kind of natural glue, much as they
would in the wild. “We sell 140 million seed oysters a
year,” she says. Those oysters, sold to oyster farmers
around the state, will eventually grow into mature oys-
ters that go for about $15 a dozen in local markets or $25
a dozen at restaurants.
In Maine the oyster-growing season lasts only five
months, from April to October. But Mook’s success
derives in part from his ability to extend this period by
growing them indoors in the colder months, beginning
in January. Like cats and dogs and chickens, indoor oys-
ters need to be fed. Mook has developed proprietary
growth and processing techniques for algae, and the
details are a company secret. He notes the minute organ-
isms are heterotrophic, meaning they can extract energy
from sugar, and they do not require light, which helpsBILL MOOK,
founder of Mook
Sea Farm in
Walpole, Maine
( above ), grows
algae in special
tanks as oyster
food. The small-
scale operation
is housed in two
huts ( bottom left ),
and oysters
are sometimes
moved to land
( top left ) from
a nearby river
so they can be
protected from
the water’s rising
acid levels.