Photos of the Long Island Sound

Our Plan

Nutrient Bioextraction in Long Island Sound

A University of Connecticut research team harvest kelp near the Thimble Islands in Branford, CT.

Ribbed mussels in Long Island Sound.







Nutrient Bioextraction combines growing and harvesting shellfish and seaweed for the purpose of removing nitrogen and other nutrients from coastal waters. Nutrient bioextraction can also provide economic benefits. Since 2009, the Long Island Sound Study has promoted efforts to bring nutrient bioextraction to Long Island Sound. In 2018, the New York State Department of Environmental Conservation and NEIWPCC with support from LISS hired a bioextraction coordinator to implement a Bioextraction Initiative.

Why is Nutrient Bioextraction Being Considered for Long Island Sound?

Reducing nutrient inputs is a priority for many estuary programs in the United States, including Long Island Sound, Chesapeake Bay, and the Gulf of Mexico. By reducing nutrients in coastal waters, states and federal agencies hope to reduce widespread and recurring problems with algal blooms, loss of seagrass, and hypoxia (low dissolved oxygen). Nutrient bioextraction can complement existing programs (such as using advanced treatment methods to remove nitrogen from wastewater treatment plant sewage discharges into the Sound). It is the only method available to remove nitrogen after it has entered the Sound.

What is Being Done to Advance Bioextraction in Long Island Sound and the East Coast?

Practical Government and Private Sector Applications of Bioextraction. Learn about nutrient bioextraction projects taking place in Long Island Sound and elsewhere along the East Coast. See examples

Ribbed Mussel Pilot Study. Learn about the pilot program completed off of Hunts Point in the South Bronx (near the western Narrows of Long Island Sound) to test the effectiveness of ribbed mussels and seaweed in removing nitrogen from the local environment. See mussel study project summary.

Ecosystem Services Assessment of Bioextraction in Long Island Sound. This research project used ecological, economic, and other models to show that oyster aquaculture in Long Island Sound compared favorably to existing nutrient reduction methods, in terms of both the cost and effectiveness of nitrogen removal. Oyster aquaculture has the added benefit of providing a sustainable source of local seafood. See research project summary.

Seaweed Pilot Studies. Learn about the pilot program completed off of Hunts Point in the South Bronx and two sites in Connecticut to test the effectiveness of seaweed in removing nitrogen from the local environment. See seaweed study project summaries.

2009 Bioextraction Workshop. In 2009, the Long Island Sound Study held a workshop to learn more about topics related to nutrient bioextraction from experts around the world and to discuss opportunities for nutrient bioextraction in Long Island Sound. See bioextraction workshop.

What is the Nutrient Bioextraction Initiative?

The mission of the Nutrient Bioextraction Initiative is to improve water quality in NY and CT marine waters by removing excess nitrogen through the cultivation and harvest of seaweed and shellfish. The Initiative will provide information to help decision makers with the guidelines needed to facilitate public and private seaweed and shellfish farming and harvest operations in their coastal waters. We do this by:

  • Assessing the efficacy of and potential challenges involved in advancing seaweed and shellfish aquaculture to remove excess nitrogen loads from NY and CT surface waters;
  • Actively reviewing and reporting on literature, permits, and policies; and providing recommendations to streamline the regulatory process;
  • Developing a GIS-based tool to identify potential seaweed and shellfish aquaculture sites for bioextraction;
  • Creating an interconnected workgroup of professionals and stakeholders that will work towards advancing bioextraction.
The Nutrient Bioextraction Initiative is a project of the New England Interstate Water Pollution Control Commission, in collaboration with the NYS Department of Environmental Conservation and the Long Island Regional Planning Council with funding from the EPA’s Long Island Sound Study program. 

What is the Bioextraction Workgroup?

The Bioextraction Advisory Committee (BAC) is a small network of interdisciplinary researchers and experts in nutrient bioextraction, seafood safety, nutrient resource management, and shellfish and seaweed aquaculture working in federal, state, and local government agencies; academic institutions; non-profit organizations; and the aquaculture industry. The BAC stays up-to-date on the work on the Bioextraction Initiative through regular webinars and provides guidance and recommendations on projects in order to produce sound science that ultimately will be used to inform management decisions.


Fact Sheets

(The 2010 fact sheet includes a graphic on how nutrient bioextraction works)

Nutrient Bioextraction Initiative (2018) – Overview of the current initiative in Long Island Sound.

What is Nutrient Bioextraction? (2010) –  Explains nutrient bioextraction and the initial efforts in LIS.

Learn More

Popular Media Links

Kelp: It’s What’s For Dinner
Focuses on GreenWave training new kelp farmers, bioextraction, and environmental benefits of farming kelp. See video.

Using Mussel Power to Clean Rivers
Focuses on NOAA pilot project in the Bronx River estuary to harvest ribbed mussels from a raft to remove nitrogen pollution. See video.

Farming Underwater: 3D Solutions for Land and Sea
Discussion on removal of nitrogen and carbon to improve water quality conditions. Connects researchers (from University of Connecticut), kelp farmers (GreenWave), and end users. See video

Seaweed Farming and its Surprising Benefits
60 minute Reporter Leslie Stahl interviews the owner of kelp and oyster farm in the Thimble Islands and UConn scientists about the benefits of kelp farm. See transcript.

A nasty tasting shellfish could be the job for cleaning rivers.
Report on a  published article in a science journal that describes the ecological benefits of harvesting ribbed mussels based on research from the Bronx River pilot study. See Economist article. | Science Magazine article

Can Seaweed Cut Methane Emissions on Dairy Farms?
Adding seaweed to cattle feed may significantly reduce methane emissions from dairy cows. See article.

The Climate-Friendly Vegetable You Ought to Eat
New York Times food writer describes the nutritional and cooking benefits of kelp. See article.


Mussel Socks

A pilot study at the location where the Bronx and East rivers meet will study the viability of removing nutrients through the cultivation of ribbed mussels. see article

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