Riverkeeper, along with a coalition of partners, is actively monitoring a large and widespread harmful algal bloom (HAB) in the Hudson River Estuary, which experts say may be the most extensive bloom in living memory. The ongoing tracking and public reporting are critical to protecting both community health and drinking water supplies.
The public is strongly advised to avoid contact with water in areas affected by the bloom, as HABs can release toxins harmful to people, pets, and wildlife through ingestion, inhalation, or skin contact. Common symptoms include skin rashes or stomach upset, while exposure to higher concentrations of more potent toxins can potentially damage the liver or neurological system. Dogs swimming in affected waters have even died after exposure.
The current HAB appears concentrated near Kingston, with observed conditions in shallow areas along the shorelines from the Village of Catskill and the City of Hudson south to the Towns of Esopus and Hyde Park. Isolated blooms have been reported elsewhere along the river. Riverkeeper notes that not all areas may be equally affected, and the duration of the bloom remains uncertain. The public is encouraged to photograph and report sightings to the New York State Department of Environmental Conservation.
Harmful algal blooms are caused by cyanobacteria, not true algae, which can rapidly multiply under warm water temperatures, stagnant flow, and nutrient-rich conditions. Climate change is intensifying these conditions, with warmer waters, droughts, and heavy rainfall increasing nutrient runoff from sources like treated sewage, fertilizers, agricultural runoff, and poorly maintained septic systems.
“HABs can pose a threat to drinking water,” said Dan Shapley, Riverkeeper’s Director of Advocacy, Policy, and Planning. “We work closely with the Hudson River Drinking Water Intermunicipal Council and the New York State Department of Health to ensure that drinking water plants are effectively treating the water for the 100,000 people who rely on the Hudson.”
Riverkeeper continues to collaborate with the NYS Department of Environmental Conservation, the NYS Department of Health, local communities, and the Hudson River Water Quality Monitoring Collaborative—a network of over 100 stakeholders including academics, regulators, municipalities, watershed groups, and environmental justice organizations—to monitor, respond to, and mitigate the impacts of the bloom.
For additional resources on identifying HABs and tracking water quality in the Hudson River watershed, visit Riverkeeper’s Water Quality Portal at data.riverkeeper.org.
Riverkeeper remains committed to safeguarding the Hudson River, promoting swimmable, fishable, and drinkable waters, and addressing the broader challenges of climate change and pollution. Learn more at riverkeeper.org.