Oyster farming appealed to me for many reasons, chief among them how inherently sustainable growing oysters for food is. Sea farming is often tucked under the larger “fisheries” umbrella because we go to work on the sea in boats and come back with food to sell. But there are big differences between the work of fishermen and aquaculturists.

At its core, oyster farming is one of the most sustainable means of food production in that it doesn’t require any natural resource extraction from the environment. In fact, when farms are run responsibly, studies show, oysters not only cause no harm to the environment but also provide valuable ecosystem services.

Oysters are filter feeders. They feed by gulping in seawater, filtering it through their gills, and extracting their food in the process, primarily phytoplankton and algae. Since farm-raised oysters get all their food from the natural environment, they don’t have to be fed.

There also aren’t any other inputs commonly required in other kinds of farming — no fertilizers, pesticides, antibiotics, fresh water. On an oyster farm, nothing goes into the ocean except the oysters and the gear needed to support them.

There are two big environmental benefits to oyster farming. First, there is no need for an external food source or other additives to ensure oysters’ healthy growth to harvest day. Second, through the filter-feeding process, oysters also help mitigate some of the impacts that human activities have had on the chemistry and environment of our coastal waterways.

Oysters are a species that once existed in great numbers in Maine before being overharvested. Introducing more of them into our bays and estuaries can help moderate the higher-than-normal amounts of nitrogen and carbon now found in our ocean water, thanks to human shoreside activities and runoff. Through their feeding process, oysters sequester nitrogen and carbon into their shells and tissues. Filter-feeding animals like oysters can also help improve the clarity of seawater, allowing more sunlight to reach deeper and helping valuable ecosystem members such as eelgrass recover lost ground.

This kind of food production is only truly sustainable, however, if it exists harmoniously and benefits the community where it’s located. In my own oyster business, I’ve worked hard to ensure that where and how I operate are as sustainable as possible for both the community and bay. By choosing to keep my business and my farm small, I can grow oysters in my home waters of Casco Bay while limiting the impact I have on other users on the water. By using smaller, lighter-weight gear and farming in shallow water in a big open area, I can take advantage of the wind and waves to do most of the physical tumbling that cage-grown oysters require and reduce my reliance on fossil-fuel-powered equipment. And finally, by selling everything I grow directly to my greater community through weekly farmers markets and a community-supported aquaculture program, I provide a significant amount of fresh, healthy protein directly to my community in a way that is affordable, reliable and accessible.

Maine’s working waterfront has always been a vibrant, strong community of small-scale business owners and operators, and with support, small-scale sustainable oyster farming stands to complement and strengthen our waterfront infrastructure and traditional way of life into the future.

Emily Selinger owns and operates Emily’s Oysters, a 4-acre oyster farm and direct-to-consumer retail business based in her hometown of Freeport.