How Much is a Clam Worth to Long Island Sound?

Clams and oysters are an important source of seafood and support a vitally important aquaculture industry for Long Island Sound. But did you know that oyster and clam aquaculture also serves an important ecological role in improving water quality in the Sound?

Shellfish feeding and nutrient uptake is measured at a watershed in Greenwich for research about shellfish to support their role in the ecology of the Long Island Sound.
Field experiments to measure feeding and nutrient uptake by shellfish in the Greenwich watershed in 2015. Credit: NOAA Fisheries/Julie Rose

The shellfish take up nutrients such as nitrogen when they filter feed on phytoplankton (commonly known as algae). By reducing excess algae in the Sound, they are also reducing the chance of algal blooms that can rob coastal waters of the oxygen fish and other animals need to breathe. Recently, the NOAA Northeast Fisheries Science Center’s Milford Lab, working with partners including the NOAA National Centers for Coastal Ocean Science and Stony Brook University, set off to find out just how valuable shellfish are in improving water quality in the coastal waters of Greenwich, CT. In the study, recently published in Environmental Science & Technology, the researchers determined that it would cost between $2.8-$5.8 million a year in infrastructure improvements, such as wastewater treatment upgrades and stormwater best management practices, to remove the same amount of nitrogen as the “ecosystem services” provided by shellfish.

An article on the NOAA website describes how the researchers estimated the ecological and economic value of nitrogen reduction that results from oyster and clam aquaculture. It also describes how the researchers collaborated with local shellfish growers and the Greenwich Shellfish Commission to get the harvest data they needed for the study.

Three of the study’s authors serve on Long Island Sound Study committees: Gary Wikfors, chief of the Aquaculture Sustainability Branch at the Milford Lab, serves on the Management Committee; Julie Rose, a research ecologist at the Milford Lab, serves on the Science and Technical Advisory Committee (STAC), and Anthony Dvarskas, an economist at Stony Brook University, now with the New York State Attorney General’s Office, also serves on the STAC. The research is consistent with an Implementation Action of the Long Island Sound Study Comprehensive Conservation and Management Plan to “conduct primary valuations of the critical ecosystem goods and services supported by Long Island Sound and its coastal habitats.”

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