An algae bloom has been discovered in a section of the Charles River and people are urged not to swim, boat, or fish in the area until further notice.
The algae, known as cyanobacteria, was confirmed downstream of the Harvard Bridge on Thursday by the state Department of Public Health.
The area of concern extends from the Harvard Bridge, which connects the Back Bay to Cambridge, to the Museum of Science.
Officials warned that people should also keep their pets away from the water.
According to a fact sheet by the public health department, exposure to cyanobacteria can lead to “gastrointestinal symptoms, skin rashes, irritation of eyes, nose, and throat, and neurological or liver damage.”
“Algae blooms may last for weeks in the summertime or may disappear quite quickly,” officials said in the advisory. “The Massachusetts Department of Public Health (DPH) will continue to monitor cyanobacteria algae levels in this area.”
Truman Dickerson can be reached at truman.dickerson@globe.com.