Oyster Gardens
Course cultivates shellfish lovers who want to grow their own

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Amber Tonry has never eaten an oyster, raw or otherwise, but she will get her chance later this year when the oysters that she and her husband Rick are raising in the Damariscotta River get big enough. The Tonrys are taking a new University of Maine course that is teaching people how to grow the prized shellfish for their own use, just as they would raise tomatoes or lettuce in their kitchen garden.

University of Maine Cooperative Extension Associate Dana Morse, who is affiliated with the Maine Sea Grant College Program, and Chris Davis, an oyster grower and director of the Maine Aquaculture Innovation Center (MAIC), are the instructors for the oyster garden course held in Damariscotta and Blue Hill. Starting in March 2004, they focused on oyster biology, water quality and aquaculture regulations. When the 18-month course ends this fall, students will have a broad view of how humans affect coastal ecosystems, and the practical skills to grow a valuable shellfish.

To help defray the cost to students, Maine Sea Grant, the Maine State Planning Office and MAIC provided financial support, working in partnership with the Damariscotta River Association, Pemaquid Oyster Co., and Bagaduce River Oyster Co. The course is designed for noncommercial oyster growers; Davis teaches a separate course for people starting an oyster business.

Last summer in the Damariscotta River near Dodge Point, the novice oyster farmers aboard the Seaducktress deployed their spat in plastic floating trays.

The tiny oysters, each less than a quarter-inch long, were held in the black trays by orange bags like the one being emptied by Lincoln Brown.

By the end of the first summer, many of the oysters were nearly 2 inches long. They wintered in a wet lab at the Darling Marine Center before returning to the river this summer.

Retired professor Donald Huffmire and Savick Harvey check on the floating nursery. Photos by Dana Morse and Linda Healy

The oyster gardening students bring a variety of experiences to the task. They include a commercial fisherman, a high school biology teacher, a retired university music professor, and a grandmother and her grandson. Morse remembers the excitement of the first class gatherings. "They wanted to get their babies in the water and watch them grow," he says.

In mid-summer, the students got their chance. They received about 1,000 spat, baby oysters less than a quarter-inch long that were produced at UMaine's Darling Marine Center in Walpole, Maine. Students placed their spat in containers, also called "bags," made out of sturdy, fine-mesh plastic. Attached to plastic floats, the bags are designed to stay on the surface of the water and provide oysters with constant exposure to their primary food source, the microscopic plankton that flow back and forth with every passing tide. Students were responsible for mooring their bags in an estuary or bay at a location specified in their short-term state permits.

For the next five months, students tended the bags weekly, keeping them free of fouling by algae and occasionally dividing their growing crop into new bags to avoid overcrowding. By late fall, the oysters had grown to nearly 2 inches long.

Morse traces the first oyster garden program to the Chesapeake Bay, where, in the 1980s, the goal was to restore overharvested reefs. Subsequently, the idea spread to North Carolina, New Jersey and New York's Long Island Sound. Some programs aimed at oyster reef restoration, while others served people who simply wanted to eat their own homegrown shellfish.

"One of the main things they (instructors) found was that it was really engaging to people," says Morse.

"They were getting an education in biology and ecology." Among the topics covered in the UMaine course is phytoplankton. Sarah Gladu, coordinator of Cooperative Extension's volunteer phytoplankton monitoring program, taught students how to collect phytoplankton with a net and identify them with a handheld microscope.

For Amber Tonry, participating in the UMaine course seemed a natural extension of living by the shore. The Tonrys are lobstermen and operate their boat, the Sea-ducktress, from their dock near Dodge Point on the Damariscotta.

Since the Tonrys were on the water on a daily basis, they were able to check on their bags regularly. During the 2004 Oyster Festival in Damariscotta, they also took people out to get a firsthand look at their crop. "It's amazing to see how easy it is. You have to tend them once a week, but they pretty much take care of themselves," says Amber.

Mark DesMeules, executive director of the nonprofit Damariscotta River Association (DRA), is also taking the class. DesMeules says his whole family, including his children, love to eat raw oysters.

The oyster garden course dovetails nicely with the DRA's mission to educate people about the health of the river and estuary, DesMeules says. "(The course) helps people become more knowledgeable about the river as an ecosystem and about the importance of clean water. We've had discussions about how land use affects water quality and about invasive species. With this project, we're using a native oyster (the American or Eastern oyster, Crassostrea virginica). European oysters have been put into the river, and we don't really know if that could be a problem or not."

While raising oysters gives people a new understanding of the coastal environment, the course also has led participants to consider competing uses of the river. Among lobstermen, kayakers, shoreland owners, aquaculturists and others, the potential exists for conflicts. Coastal waters are a public resource, and students got a taste of how public policies address one aspect of this issue — oyster aquaculture — through the state permit application process.

"How many oyster leases can you have? You also have fishermen who need access to their docks. Shoreland owners like the views from their homes. Kayakers really don't want to be paddling through lots of oyster bags," says DesMeules.

Oysters go into a period of hibernation during the winter, and growers typically remove them from the water or anchor them to the bottom where they are safe from ice and the occasional Arctic chill. Before ice began to accumulate on their bags last winter, most class participants stored their oysters in tanks at the Darling Center. Others put them in refrigerators or down on the sea floor.

By this past May, the young oysters were back in the sunlight at their lease sites, where they continued feeding and growing. Students were learning about oyster predators such as birds and the diseases that can threaten their crops before they mature.

This fall, the oysters should reach about 3 inches in size — and be ready to eat. While they could continue to grow (American oysters can reach up to 8 inches long), Morse and Davis plan to host an oyster feed to celebrate the students' success.

by Nick Houtman
September-October, 2005

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