2025 Pathogen Monitoring Network

The 2025 Pathogen Monitoring Network season has officially started! Since the beginning of May, ten groups have been sampling throughout Connecticut and New York to gather crucial fecal indicator bacteria data to fill data gaps in the Long Island Sound watershed. This network aims to create a coordinated, geographically strategic, scalable monitoring network for fecal indicator bacteria in the Sound in order to inform sound-wide management and restoration actions. From its start in 2023, the network has grown each year to work towards this goal.

This year, one new group has been added- the Alliance for the Mystic River Watershed. This group will provide data for four tributaries into the Mystic River Estuary- Long Pond, Bush Pond, Williams Brook, and Whitford Brook. This estuary has historically dealt with bacterial contamination and is currently unsafe for fish and shellfish consumption. However, many of the tributaries into the estuary remain largely untested. Long Pond and Bush Pond are two significant freshwater sources for the estuary, and their bacterial levels are currently unknown. The sites on the Williams and Whitford Brooks are located directly before and after the Ledyard WPCA Water Treatment Plant, in order to collect data to assess the plant’s impact on bacterial levels flowing into the estuary. The Mystic River Estuary flows directly into the Long Island Sound, making this an essential addition for a more comprehensive evaluation of the Sound’s bacterial contamination.

Pathogen sampling on the Long Island Sound will provide important information about sources of contamination throughout the waterbody. As this network continues to expand, the data will inform decisions for future reductions in bacterial levels, including increased testing, trackdown efforts, and other solutions as necessary. The Pathogen Monitoring Network’s efforts work towards a cleaner future for the entirety of the Long Island Sound.

Learn more about the program here.