BOSTON (WBZ NewsRadio) — The Department of Public Health issued a health advisory Monday about a harmful cyanobacteria algae bloom in the Charles River.

Cambridge Public Health Department said residents should avoid areas downstream of the River Street/Cambridge Street bridge, including Magazine Beach and the BU and MIT boathouses in addition to Broad Canal, Lechmere Canal, North Point Park, Lederman Park, the Community Boating docks, and Storrow Lagoon.

“I clean my boat more just so that like it’s not getting on my body or my clothes without me knowing,” Sarah, a rower on the Charles, told WBZ NewsRadio.

Cyanobacteria algae is a blue-green algae that enters the river through fertilizers, wastewater and animal waste. It grows rapidly in warm waters and produces toxins that are harmful to people, animals and the environment.

The last time an algae bloom health advisory was issued in the river was during the summer.

“It’s really frustrating to have to deal with when you don’t have to deal with this on other bodies of water, but it’s part of rowing on the Charles so we try to do as much as we can to stay safe and healthy,” Gabriel added.

There are currently 30 bodies of water in Massachusetts reported with cyanobacterial algae bloom:

Parker Pond - Barnstable

Lake Holland - Belchertown

Back Bay Fens - Boston

Charles River (Downstream of the Cambridge St./River St. Bridge) - Boston/Cambridge

Sprague Pond - Boston

Quaboag Pond - Brookfield

Brookline Reservoir - Brookline

Chebacco Lake - Essex/Hamilton

Seymour Pond - Harwich/Brewster

West Reservoir - Harwich

Redd’s Pond - Marblehead

Santuit Pond - Mashpee

Capaum Pond - Nantucket

Hummock Pond - Nantucket

Washing Pond- Nantucket

Carbuncle Pond - Oxford

Pontoosuc Lake - Pittsfield

Billington Sea - Plymouth

Boot Pond - Plymouth

Clear Pond - Plymouth

Ezekiel Pond - Plymouth

Great South Pond - Plymouth

Little West Pond - Plymouth

Round Hole Pond (Esta Drive) - Plymouth

Scokes Pond - Plymouth

Congamond Lakes—Middle Pond - Southwick

Beaman Pond - Templeton

Pratt Pond - Upton

Lake Quannapowitt - Wakefield

Hardy Pond - Waltham

Meanwhile, the Head of the Charles Regatta is still expected to take place on Oct. 17 – 19.

WBZ NewsRadio’s James Rojas (@JamesRojas.bsky.social) reports.