Cyanobacteria Alert Issued for Blackey Cove (Moultonborough)

[Descant]

Originally Posted by John Mercier

Nutrient loading can be the result of nutrients that are trapped in the bottom soils and released during an upwelling (which is why it can happen below the ice), or any time that water is ''stirred'' by either weather or other activities.

Does this mean we're creating more problems using bubblers to protect docks? I always wondered if these circulators are raising the overall temp of the lake, and is there a long term impact.

[icg56]

Bubblers that pump cold air into the Lake to move water or circulators should expose the Lake to colder temperatures, not warm the Lake. Ice acts as an insulator against the cold of winter below the ice, so anything that exposes warmer deep water to cold air should lower, not raise, the Lake temperature. In any case, the net effect of all these devices is trivial compared to the large body of water represented by the Lake.

[John Mercier]

Originally Posted by icg56

Bubblers that pump cold air into the Lake to move water or circulators should expose the Lake to colder temperatures, not warm the Lake. Ice acts as an insulator against the cold of winter below the ice, so anything that exposes warmer deep water to cold air should lower, not raise, the Lake temperature. In any case, the net effect of all these devices is trivial compared to the large body of water represented by the Lake.

I think as another localized source, even if they were... we should notice a bloom always near the bubbler - which doesn't seem to be the case.

Nutrient loads are strongest near a sourcing. The blloms in various parts of the lake seem less likely to be a point source and more a dynamic of generality.

Imagine that I was able to run a dye through the bubbler; you would see that right near the bubbles surfacing the dye would be vary noticeable, but as it diffused through the larger body, it would be impossible to see.

The bubbler would need to be moving the nutrient load from the soil toward the surface.

[ITD]

Originally Posted by Descant

From John Mercier: "Nutrient loading can be the result of nutrients that are trapped in the bottom soils and released during an upwelling (which is why it can happen below the ice), or any time that water is ''stirred'' by either weather or other activities."

Does this mean we're creating more problems using bubblers to protect docks? I always wondered if these circulators are raising the overall temp of the lake, and is there a long term impact.

No, bubblers have little impact.

[Lakegeezer]

Here's a photo from 360 feet above the stream that feeds from Lake Kanasatka into Blackey Cove. Looks like there are sandbags holding back the slime. The second photo shows where the green water changes to blue.