Harmful Cyanobacterial Bloom Advisories in Massachusetts current as of December 11, 2025

This list includes waterbodies that have been reported to DPH by local, state and federal partners that manage or regulate the respective waterbody.

  • Lake Attitash, Amesbury
  • Brookline Reservoir, Brookline
  • Redd’s Pond, Marblehead
  • Great South Pond, Plymouth
  • Scokes Pond, Plymouth
  • Lake Quannapowitt, Wakefield

Please note: This should not be considered a complete list of all advisories in Massachusetts. This list includes waterbodies that have been reported to DPH by local, state and federal partners that manage or regulate the respective waterbody. If you think an algal bloom may be present you are encouraged to avoid contact with the water — WHEN IN DOUBT, STAY OUT! To see examples of what algae blooms look like, please visit the Identifying cyanobacterial blooms and scums page.

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