Mike the Mad Biologist

Algal Bloom in the Charles River?

I was at the Esplanade in Boston, and I noticed something very weird in the water. By the Fairfield St. entrance, the water under the bridge and by the shore (on both sides, river and ‘canal’) was bright green, as if someone had dumped dye or paint in the water. When I got real close and then fished out some of the green water, I noticed that it wasn’t die or paint at all, but tiny (<1mm) algal colonies (I think). I have no idea what kind of algae they were (sorry, I didn't have my dissecting microscope handy). If there are any other Bostonian readers, have you seen this? And whom does one contact about this--both to alert someone and to find out more information?


  1. #1 Joshua
    August 6, 2006

    I used to see this all the time, particularly near the place where the Muddy River meets the Charles just east of Kenmore Square. They’ve done some kind of construction in that area under the overpass, though, and I think there was some clean-up involved.

    I’m not sure who you’d call about it, though. There’s always CityofBoston.gov, I suppose.

  2. #2 apalazzo
    August 6, 2006

    I saw it too at the Mass Ave bridge. It was as thick as paint.

  3. #3 Tulula
    August 7, 2006

    It looked like long, flowy bright green hair. It also smelled a bit like gasoline, I thought. Did you notice it too?

  4. #4 Ken Benet
    August 12, 2006

    My wife and I tried to sail dingies down at Community Boating this morning and were told that we could not do so due to the algae bloom. Apparently, sun and the confluence of other random elements (such as hot weather) have caused this phenomon. One side effect of the algae is that it produces some sort of toxin that caused eye and skin irritation and if it is present in high enough concentrations, liver damage(!). According to the literature that Community Boating showed us from the MA Dept of Health, rain and cooler temperatures should halt and then disperse the algae.

  5. #5 Mick
    August 13, 2006

    Try the Charles River Watershed Association:


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