Updated: Aug 25
Dr. Danielle Wain with 7 Lakes Alliance has shared the following update on North Pond’s condition.
As many have noticed, the current algae bloom on North Pond has moved into a new phase. The “good” news is the algae appears to be dying, which is why the water has a different color and texture than earlier in the bloom. 7 Lakes’ algae tracker shows blue-green algae is declining. When they die, they release green pigments (chlorophyll) and blue-green pigments (phycocyanin) into the water, which makes it look even worse than previously. This can be the most dangerous time in a bloom; in addition to releasing their pigments, the algae will release toxins into the water when they die. Fortunately, results of 7 Lakes’ toxin testing this week did not show the presence of microcystin, the most commonly observed toxin in Maine. Still, stay out of scummy water!
Once the algae start dying, they will start to suck oxygen from the water as they decay. As a result, we could see some dead fish again, as we did in 2020. This year’s bloom hasn’t been as bad as in 2020, so we might not see the same thing happen. But it is always a possibility.
Little North Pond has begun to see more scum blown into that basin. Water clarity was to the bottom in the middle of Little North, but the edge of the lake near North Pond is experiencing some of the same impacts as the main lake.
Water clarity in North Pond is 5 feet, indicating algae to at least that depth. That is confirmed by our profiling measurements, showing elevated chlorophyll down to 10 feet.
Manipulating the dam will not remove the algae problem and will pass part of the problem downstream into Great Meadow Stream. Conditions will likely change with the cooler, rainier weather this week. But there is still hot weather on the horizon this month, so we might not be out of this yet.
Photo from 7 Lakes Alliance