Oysters: Salivation and Salvation of Maine’s Coastal Environments

Oysters have long been known to be “ecosystem engineers.” These small but powerful bivalves can filter as much as five gallons of water a day as they feed on algae and other microscopic detritus, which directly correlates to significant improvements in water quality. At the same time, more than any other type of food, the flavor profile of an oyster also strongly exhibits a sense of time and place, much like architecture can in the built environment. 

Maine’s unique geology along its southern coast provides an ideal location for oyster growth. Waters in the finger-like coast are often very cold, which means that oyster growth here is slower (3-4 years for a full-size oyster) compared to other warmer water locations, but this also contributes to a very full-bodied flavor profile since the oyster has more time to develop in its habitat. Unfortunately Maine’s wild oyster population became extinct in the 1940s due to both over harvesting and pollution from several brickyards located along the river, with piles of red clay bricks still dotting the shores. Yet just a few decades later, the hard work of environmental activists and cultivators has led to a recent resurgence of wild oysters.

I visited mid coast Maine and the Damariscotta River, a well-known estuary for oyster growth for thousands of years, to taste some of the freshest and most popular oysters, learn about the growing industry, and experience this beautiful landscape. 

The Whaleback Shell Midden State Historic Site is home to one of the largest oyster shell middens, a former Native American dumping ground for discarded shells with some as large as 1 foot long, which has been transformed into a public park. A large number of the shells from the midden were partially repurposed in the late 1880s and processed into chicken feed. However, remnants of the midden are still very much present along the eastern bank of the upper Damariscotta and a short hike to the edge of the river provides views to the Glidden Midden across the way.

While touring Glidden Point oyster farms, the farmer explained that freshwater from the lakes region flows southward to help balance the salinity and minerality of the Atlantic Ocean. The significant 11-foot tidal changes are constantly delivering nutrients to oysters at all levels of the 80-90ft deep river. It is this movement which also contributes to robust shell growth for a highly marketable oyster: one that is easy to shuck with a flat “lid” and has a cup that cradles the oyster in its brine, making for a delectable oyster experience. There are nearly a dozen different types of oysters being cultivated at various locations along the river, yet each type is unique in terms of appearance and flavor profile.

The term “Damariscotta” is a corruption of an Algonquian term meaning “place of an abundance of alewives,” which are small salty fish that spawn in the river and are just one of the many species that play a role in the cycles to keep the estuary healthy. During a kayak tour of the Damariscotta, a number of double-crested cormorants, osprey, eagle nests, and even a harbor seal could be seen during just a short 3-hour paddle down the river. Oyster cultivation and the positive effects on the water quality over recent decades have enabled this biodiversity not only to grow but to thrive.

With such a positive impact, one might wonder why oyster farmers are not compelled to increase oyster growth to continue to increase the water quality and thus the quality of their product. Currently there appears to be no incentive for farmers to do so, and there are a number of factors to consider, including leasing procedures and farming technology. 

Oyster farming leases and sites are controlled by the state and a 10-20 year lease can take 2-3 years to obtain. Farming technology has also continued to evolve with recent developments by Mook Sea Farms. One of two hatcheries in the state, Mook provides “seed” for dozens of local oyster farms as well as cultivates their own oyster varieties in the Damariscotta, one of which are called Moondancers. It is through this cultivation process that they have developed a cylindrical “Flow N Grow” system. In contrast to rectangular mesh bags that float on the water surface, the Phase 3 “Flow N Grow” allows surface culture oysters to be automatically turned just at or below the surface of the water, are spatially more efficient, and allow for the equipment to be largely out of sight of the pastoral views across the river. 

Oysters are truly powerful filters that have the unique ability to both help establish and allow estuaries like the Damariscotta River to flourish. With a new-found appreciation for both their positive environmental impact and the time and care needed for their cultivation, whenever I have the opportunity to enjoy a Moondancer, I’ll be able to close my eyes and see that oyster’s beautiful home.

Resources:

Jacobsen, Rowan. A Geography of Oysters.
Jacobsen, Rowan. The Essential Oyster.
Maine Oyster Trail: https://seagrant.umaine.edu/wp-content/uploads/sites/467/2019/09/2019-maine-oyster-trail-map.pdf
Mook Sea Farm: https://www.mookseafarm.com/
Coastal Rivers Conservation Trust: https://www.coastalrivers.org/about-us/river-facts/