Toxic bacteria outbreak strikes before the Head of the Charles

"An outbreak of toxic cyanobacteria is plaguing the Charles River just a week before the waterway hosts the world's largest three-day rowing competition. The 2025 Head of the Charles Regatta takes place in Boston and Cambridge from Oct. 17 to 19. The iconic event will feature roughly 12,000 rowers and draw thousands of spectators along the Charles River. According to a Mass.gov emergency alert, the water downstream of the Cambridge Street/River Street bridge and Back Bay Fens has been reported harmful as of Oct. 6."

""With climate change bringing increased precipitation and extreme heat, cyanobacteria blooms are becoming more frequent and long-lasting," Stefan Geller, of the Charles River Watershed Association, told the Boston Globe. "The Charles River has had cyanobacteria blooms almost every summer for the last decade." Due to high temperatures and heavy rainfall, several Massachusetts waterbodies have developed cyanobacteria blooms, according to the Department of Public Health."

An outbreak of toxic cyanobacteria is affecting the Charles River a week before the 2025 Head of the Charles Regatta, scheduled Oct. 17–19 in Boston and Cambridge. The event will feature roughly 12,000 rowers and attract thousands of spectators along the river. A Mass.gov emergency alert reported water downstream of the Cambridge Street/River Street bridge and Back Bay Fens as harmful as of Oct. 6. High temperatures and heavy rainfall have contributed to blooms across several Massachusetts waterbodies. Cyanobacteria can cause skin rashes and eye irritation, posing health risks to rowers. Organizers expect cooler temperatures to help clear blooms and are coordinating with state officials to monitor conditions.

Read at Boston.com