Cleaning up that dirty water: Massachusetts Oyster Project at Boston Harbor

On a balmy, overcast October afternoon, I found myself wearing pink gardening gloves and digging through a large wheelbarrow full of dirty, year-old oysters. I wasn’t shopping for the evening’s dinner; these oysters aren’t meant for human consumption. I was helping sort oysters that would go back into Boston Harbor. I volunteered with the Massachusetts Oyster Project for their oyster seed planting–a citizen science effort to test whether oysters could once again thrive in the harbor.

Oyster reefs once created a prominent necklace along the North American Coastline, especially in New England. In his 1941 Geographical Review article, Gordon Sweet writes about how Native American cultures on both coasts valued the oysters and their shells for sources of food, arrowheads, and commerce. The best evidence of this probably comes from the ancient, stories-high shell heaps in Damariscotta, Maine.

It was not long before new European settlers began to plunder the oyster beds for their own food supplies. Sweet’s report mentions that New England’s oyster population began to decline at the end of the 17th century and continued  into the 18th century. The year before the colonies declared their independence from Britain, collectors in the Cape Cod town of Wellfleet had exhausted their own oyster beds. The decline only continued–oyster reef conservation scientists estimate that the global oyster reef population declined by 85 percent since the 1800’s. Overfishing, dredging, pollution and disease all contributed to the oysters’ decline. In Boston’s case, urban growth such as filling in tidal flats and pollution also contributed to oyster reef destruction. Most of the oysters we eat today come from oyster farms–75 percent of which are located along  North America’s East and Gulf Coasts

Oysters stick to each other to create  reefs that provide a fertile bed for wildlife diversity, water filtration, denitrification, and erosion protection along coastlines. Reefs thrive in estuaries, where ocean salt water mixes with river fresh water, such as the mouth of the Charles River in Boston Harbor. Oysters’ filter-feeding abilities allow them to clean water of bacteria, pollution, and algae. Each oyster can filter up to 2 liters of water an hour. The impressive filtering capacity makes them effective cleaners and “sentinel species” that show signs of pollution, disease, and poor water quality. Massive oyster reefs can also protect coastlines from erosion.

For the past four years, the Massachusetts Oyster Project has worked to prove that oysters can survive and sustain themselves in Boston Harbor. According to an interview with WBUR, Mass Oyster started when dentist-turned-venture capitalist Andrew Jay read a copy of Kurlansky’s The Big Oyster, a history of oysters in New York. Since then, Jay and his fellow volunteers have been planting oysters into the harbor.

On a recent Saturday, more than 30 volunteers of all ages, mostly parents and their young children, congregated at the Constitutional Marina boathouse in Charlestown to plant  oysters. Jay, wearing a green t-shirt that read “Oysters can filter up to 30 gallons of water a day,” greeted volunteers with a smile as they approached the picnic tables on the marina dock. Once everyone congregated at the marina, they trooped to the dockside, where Jay appeared with two purple mesh bags containing nearly 65,000 dime-sized oysters. Volunteers funneled the young oysters into long mesh tubes tied closed on each end, which they dropped into designated places in the harbor. Keeping the young oysters in the nets helps protect them from predatory starfish and crabs while they are growing.

One of the veteran volunteers gathered kids to follow him to another location along the dock. Here, the young volunteers shuffled through wheelbarrows full of loose piles of large, dirty oysterswhich Mass Oyster had planted in the harbor in 2010. Many stayed alive and were almost big enough to eat, if the diner didn’t mind a horrible stomachache.  Volunteers released these older oysters from their growing chambers and dropped into another part of the Boston Harbor with the younger oysters.

Once we removed stray fish, crabs, and starfish from last year’s groups of oysters, the volunteers and I starting putting the older oysters into net tubes just like we did with the younger ones. As we did this, veteran Mass Oyster volunteer and scuba diver Dave Wolfe pulled up to the dock with his speed boat. Wolfe and eager volunteers, mostly children, took multiple trips to the other end of the Boston Harbor in order to drop the oysters overboard into a specified part of the Boston Harbor. We needed to put them in a part of the water that poachers couldn’t reach.

The event lasted three hours. Then the oysters are  on their own until the spring, when Jay and Wolfe will gather some divers together to check on the oysters. Hopefully efforts like Mass Oyster’s could clean the harbor’s “dirty water” enough to bring a healthy oyster reef ecosystem back to Boston.