EDIT JULY 15, 8008. I GOT AN E-MAIL FROM MY CONTACT AT CRWA AND SHE OFFERED A FEW CLARIFICATIONS. HTEY HAVE BEEN ADDED IN ALL CAPS BELOW.

July 2, 2008
This picture was taken this morning at Lechmere Canal. The lovely green streaks on the surface are the same blue-green algae that have caused problems for the last couple of years.It seems early for this stuff to be so visible, but we have had a lot of rain lately which causes a lot of chemicals to be put into the river with the runoff. Combined with the the droppings of the exploded population of Canada Geese, the tons of fertilizer added at the Ebersol baseball area at the Esplanade, and the heating of the water by the Mirant electric generation plant at Kendall Square, we have quite a soup cooking.

July 3, 2008 11:00 AM
I just spoke with someone at Charles River Watershed Association and she confirmed that the stuff in the photo MAY BE microcystis. It is not AS harmful while it is alive, but when it dies it gives off a liver toxin that can persist in the water for weeks. IF YOU OR YOUR PET SWALLOWS A QUANTITY OF WATER WITH LIVE CYANOBACTERIA, WHEN THE CELLS BREAK DOWN IN YOUR DIGESTIVE TRACT, THE TOXIN WILL BE RELEASED AND CAN DO DAMAGE. DOGS PLAYIING ON THE BANKS AND DRINKING WATER CAN EVEN DIE. WATCH YOUR CRITTERS! Monitoring samples are sent to the DEP lab in Worcester, and no hazardous levels have been found so far this year. Phosphorus in runoff is the limiting factor in growth of these photosynthetic organisms. The main sources are storm water runoff from treated lawns and paved areas. The CRWA spokesperson said it would be a stretch to blame these outbreaks solely on the renovation of the ballfields on the Esplanade. She was, however, unaware of any environmental studies of this project.

There is another cyanobacteria called anabaena which is visually distinct from microcystis in that it does not clump and turns the water a cloudy pea green. Anabaena releases a neurotoxin. (Yum!) We had a lot of that late last summer.

You can get more information on this from the Charles River Watershed Association. CRWA Cyanobacteria Search