The Ecology of an American Dream

Every 4th of July, my family and I head to Cape Cod to spend the holiday weekend with my sister and brother-in-law, Jenny and Patrick Ross, at their home in Bourne, MA. Unlike many of the residents in their neighborhood, Jenny and Pat live on The Cape year round. They decided to move to Bourne full-time to fulfill Pat’s dream of starting an oyster farm.

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Bourne, MA is located on Cape Cod, just across the Cape Cod Canal and near the waters of Buzzard’s Bay.

Building an oyster business was no easy task. Pat and Jenny not only had to learn about the business and legal hurdles of oyster farming, they also had to learn about the biology of oysters and how these animals interact with their ocean environment, also know as their “ecology”. Oysters are bivalve mollusks, which means they have a two-part shell with one hinge. Inside the shell, is the oyster, a fascinating invertebrate that is coveted by humans for its flavor and also plays a vital role in marine habitats.

Oyster on a half shell. Oysters are bivalve mollusks that are coveted by humans for their flavor and also play a vital role in their habitat.
Oyster on a half shell. Oysters are bivalve mollusks that are coveted by humans for their flavor and also play a vital role in their habitat. Photo credit: https://www.monkscoveoysters.com/

Small oyster farms, like Monks Cove, represent one of the few businesses that are truly environmentally sustainable. In fact, adding oysters to the water can help the ocean. Oysters and other bivalves are filter feeders. Along with filtering the microscopic plants they use as food out of the water, the can also filter out other things, like excess nitrogen. Nitrogen is an element that is required by living things to survive, but human activity can increase ambient levels of nitrogen in the water, causing damaging consequences for aquatic organisms. Oysters can help reduce the effects of this dangerous excess nitrogen.

I recently had an opportunity to go out with Jenny and Pat on their oyster boat, “The Aw Shucks” and see first hand how they take care of their oysters and how the oysters have become a part of the local habitat. Their farm is located out in subtidal zone of Buzzard’s Bay (check out the map at the beginning of this post and the chart below).

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Monks Cove Oysters are grown in the subtidal zone of Buzzard’s May. Many farms operate in the intertidal zone, but Jenny and Pat chose a space farther out in the water to avoid recreation, conservation and residential areas. Photo credit: https://www.ecy.wa.gov/programs/sea/pugetsound/beaches/tide.html

The oysters are grown from tiny 3/4 inch babies, called seed, in special cages under the water. The cages are hauled up by a solar-powered pulley system on The Aw Shucks.

Pat and Jenny hauling up one of 100 oyster cages holding roughly 300,000 oysters!
Pat and Jenny hauling up one of 100 oyster cages holding roughly 300,000 oysters!

Oysters aren’t the only things they haul up with the cages. Wild and farmed oysters can create microhabitats for other marine plants and animals. The cages collect different types of seaweed and animals, from small young toadfish, to huge spider crabs. As the cages are opened up, hundreds of tiny crabs scrambled about to hide themselves inside their oyster bed nursery.

A baby monkfish found on Monks Cove Oyster cages
A baby toadfish found on Monks Cove Oyster cages
A spider crab, like those found on Jenny and Pat's oyster cages. Photo credit: https://www.inaturalist.org/guide_taxa/255118
A spider crab, like those found on Jenny and Pat’s oyster cages. Photo credit: https://www.inaturalist.org/guide_taxa/255118
A tiny crab. One of hundreds that fall out from their nurseries among the oysters.
A tiny crab. One of hundreds that fall out from their nursery among the oysters.

Unfortunately, some of the animals that grow on the oysters are unwanted guests. Small snails, know as “oyster drills” show up on occasion. These predators attach themselves to an oyster and drill through its shell to feed. Luckily, oyster drills have not become a problem at Monks Cove, but another creature has – the Boring Sponge. This soft-bodied parasitic animal bores into the shells of oysters and uses the shell as its home. A boring sponge infestation weakens the oysters’ shells and, sadly, Monks Cove experienced one.

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The tiny holes in this oyster shell are the tell-tale sign of a Boring Sponge infestation.

The boring sponge was no fault of Pat and Jenny, they occur naturally and have affected many oyster farms in the region where the sponge can grow. Because the sponge is such a pest, scientists have investigated ways to combat infestations. Pat and Jenny were able to use the results of scientific studies on boring sponge control to fight off the sponge at their farm. They use a special brining process that increases the salinity and dries out shell enough to inhibit growth of the sponge, but rescue the oysters.

Despite the struggles of getting a new business off the ground and unforeseen sponge infestations, Monks Cove Oysters is thriving and their oysters are delicious. The flavor of their oysters is actually a product of the specific environment in which the oysters are grown. Pat and Jenny’s farm is a unique business that is tightly linked to their community and to their local natural environment. Not only do they deliver a locally produced and sustainably grown product, but they also add a source of environmental education by giving farm tours. They are even helping out scientists as part of a study into best practices in oyster farming. Owning your own business is the classic American dream and oyster farming is an example of how to live that dream in a environmentally friendly way. I’m lucky to be able to visit one every year and learn about the amazing ecology of the oyster farm.