How We Grow Oysters In Casco Bay, Maine 

​ A Maine Oyster Primer

  • Oysters are bi-valves that grow in salt or brackish water and eat algae and microscopic organic material. 

  • By removing organic and inorganic material alike, oysters improve water clarity. This ecological service enables sunlight to penetrate the water, allowing for underwater plants to thrive.

  • Maine produced 12M oysters in 2018, the vast majority of these were the eastern species called Crassostrea virginica.

  • Maine oysters often have to hibernate in deep water during the coldest winter months and take 2-3 years to reach market size.

  • Like wine grapes, oyster flavor profiles vary greatly based on where they grow and the conditions such as salinity, temperature, water flow, kinds of algae/food.  Our oyster is imparted with all the richness from the waters of Moshier Island and Little Moshier.

  • We grow the Royal for customers who enjoy oysters on the half shell and we distribute to Oyster Bars and fine dining restaurants.

Our Oyster Nursery

At Butterfield Shellfish, we buy seed called spat or tiny 2-4 millimeter baby oysters, from a licensed hatchery located in Maine.  Our seed stays in temperature controlled conditions until spring when we put the small oysters into fine mesh bags and float them on the water or suspend them in cages.  

Our Grow Out Process

Setting up the Lines: 


After the oysters reach about a half inch in size, we transfer them into mesh bags and slide several bags into heavy metal cages.  The cages are secured in groups on lines attached to buoys and anchored to the ocean floor.

Flipping over and back:

For the next 2-3 years we flip oyster cages over and back regularly to burn off the seaweed and barnacles that attach to the bags and cages. Flipping provides added benefits in shell strength and shape helping to form the deep cup where the oyster can grow and access the natural food sources provided by the cold Atlantic waters.

Sorting and Over-Wintering: 

Most of our oysters spend the winter months near the sea floor hibernating until spring.

We harvest Royals after they have reached approximately 3 inches in length and have formed a deep cup full of that tender, slightly briny oyster that is headed for your plate.  

Our Harvest to Your Table

We hand sort oysters on our raft, bag them up and drive them to shore where our distributors deliver them to your favorite bars, restaurants and picnic spots.

Offices at 17 Haskell Ave., Raymond, ME 04071