Massachusetts warns of possible toxic algae in Charles River, advises public and pets to avoid water

The Massachusetts Department of Public Health issued an advisory on July 21 urging people and pets to stay away from a stretch of the Charles River between Kendrick Street in Needham and Spring Street in West Roxbury. The warning covers areas around Cutler Park and Millennium Park after a dog died of liver failure that may be linked to exposure to algal toxins.

State officials are investigating a suspected cyanobacteria (benthic) bloom that can be invisible on the water’s surface. Marielena Lima, river science program manager for the Charles River Watershed Association, said the algae may not look like the typical green scum. Dog owner Angie Almonte said her pet had previously drunk river water, prompting her to keep it away now. Officials have collected water samples to test for cyanobacteria cells and toxins, with laboratory results expected on July 23. Until results are reviewed, the public is advised to avoid both the water and shoreline along the affected stretch.