The Charles River Watershed Association reports cyanobacteria., a.k.a. blue-green algae, has been detected in high amounts in the Charles River basin between the Mass. Ave. Bridge and the dam, while the state reports a similar finding in the Chestnut Hill Reservoir.
The stuff is nasty and can kill dogs that ingest it after swimming in it.
Identifying cyanobacterial blooms and scums (photographs of blooms and scums)…