Press Release  Massachusetts Division of Marine Fisheries Announces Dye Study in Buzzards Bay

NEW BEDFORD — The Massachusetts Division of Marine Fisheries (DMF), in partnership with the U.S. Food and Drug Administration (FDA), the City of New Bedford, researchers, and the shellfish industry, is conducting a hydrographic dye study of wastewater from the New Bedford Wastewater Treatment Plant in Buzzards Bay to improve understanding of how wastewater discharge in Buzzards Bay impacts shellfish resources and public health.  

The study is expected to occur Wednesday, September 9, 2026, through Thursday, September 17, 2026, dependent on weather and sea state. Dye will be discharged from the wastewater treatment plant outfall on Saturday, September 12, 2026 and the flow and dispersion of treated wastewater will be tracked.  

“Here in Massachusetts, we pride ourselves on our nation-leading seafood industry, including culturally and economically important traditions of shellfishing in Buzzards Bay,” said DFG Commissioner Tom O’Shea. “We look forward to the results of this important study and are grateful for the partnership of researchers and our shellfish industry to make this possible.” 

Dye studies are common ways for researchers and managers to understand the flow and dispersion of wastewater treatment plant effluent and how nearby shellfish resources may be impacted by pollution. The results of this study will be used to validate the required shellfish closure surrounding the City of New Bedford Wastewater Treatment Plant outfall in Buzzards Bay. In addition, this study will enhance the ability to respond to events related to any potential spills or untreated discharges at the wastewater treatment plant.  

“This is a huge team effort—we are grateful to state and federal officials, wastewater operators, researchers from Woods Hole Oceanographic Institute and University of Massachusetts Dartmouth School of Marine Science and Technology, and shellfish industry leaders who will be joining us in the field to collect this important data and protect our shellfish resources in Buzzards Bay,” said DMF Director Dan McKiernan. “In particular, we want to thank two shellfish industry leaders, Dale Levitt and Scott Soares, stepping up to contribute shellfish and support this study.” 

“The upcoming dye study of the New Bedford wastewater treatment plant is a critical step in understanding the discharge coming from the outfall. The dye study will add to our toolbox, making sure that our customers get the best quality oyster we can produce in Nasketucket Bay,” said Dale Levitt, commercial aquaculture operator in Fairhaven and Mattapoisett, Vice President of the Massachusetts Aquaculture Association, and member of the Massachusetts Shellfish Advisory Panel. “The dye study continues a close collaboration between shellfish harvesters and the Division of Marine Fisheries to ensure the quality of shellfish coming from Buzzards Bay.” 

The dye used for this study, Rhodamine WT, is a water-tracing dye that is approved for use by the U.S. Environmental Protection Agency (EPA) and will not cause environmental harm. Safe concentrations of the dye will be introduced from the City of New Bedford Wastewater Treatment Plant beginning early on the morning of Saturday, September 12, 2026, and will be injected into the wastewater effluent for 12.5 hours. Dye will be visible in the water during this time and for a period afterward while the dye dilutes and disperses. This is the only dye injection period scheduled during the study. Due to the dye injection, portions of New Bedford Harbor and Buzzards Bay may appear discolored and turn red or pink for a brief time. For questions about this study, please contact Shellfish Program manager at christian.petitpas@mass.gov.

About DMF’s Shellfish Program:  

The National Shellfish Sanitation Program (NSSP), is a federal, state and industry cooperative program that sets standards for shellfish safety to protect public health. The U.S. Food & Drug Administration (FDA) evaluates Massachusetts annually to ensure compliance with NSSP requirements. Massachusetts Division of Marine Fisheries (DMF), Massachusetts Department of Public Health (DPH), and Massachusetts Environmental Police (MEP) are responsible for ensuring compliance with these standards in Massachusetts.   

To accomplish this, DMF manages shellfish growing areas statewide. Growing area classifications (Approved, Conditionally Approved, Restricted, Conditionally Restricted, and Prohibited) are assigned based on sanitary surveys of pollution sources, water quality, and environmental conditions to ensure shellfish harvested from these areas meet public health standards. See DMF’s Shellfish Classification Areas. Additionally, DMF is required to close shellfish growing areas on an emergency basis, regardless of their classification, when there is a known pollution source like stormwater runoff from heavy rainfall, sewer overflows, oil spills, or naturally occurring risks such as red tide and other biotoxins.

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