Blue-green Algae in Massachusetts
11 confirmed blue-green algae reports in Massachusetts, 1 still active. About this disease: symptoms and prevention.
11
Reports on record
1
Currently active
0
Last 7 days
1
Last 30 days
Where in the state
3
3
2
1
1
Recent reports
Blue-green Algae
Active · Aug 20, 2026
Boston
Charles River Lower Basin downstream of the Massachusetts Avenue Bridge (Esplanade side); BPHC advisory 8/20, expanded 8/27 downstream of the BU Center for Computing. Do not let dogs swim or drink. Separate advisory from the July upstream West Roxbury stretch
Source ↗Blue-green Algae
Historical · Jul 24, 2026
Brewster, Barnstable County
Walkers Pond (landing off Slough Rd), Brewster
Source ↗Blue-green Algae
Historical · Jul 22, 2026
Boston, Suffolk County
Charles River, Kendrick St (Needham) to Spring St (West Roxbury), including Millennium Park and Cutler Park
Source ↗