A curious red color has shown up on the lakebed in Pickerel Cove near the Young’s Brook inlet, so we asked the experts at the UNH Cooperative Extension to help us understand what’s causing this phenomenon.

The Young’s Brook sampling location was tested on May 22nd and no unusual coloration was observed.  What we are seeing may be iron bacteria on the lake bottom.  NH Department of Environmental Services has a Fact Sheet that discusses iron bacteria, and this Iron Bacteria Fact Sheet offers a couple of images.

During wet years, or periods when the water table is higher than normal, UNH Cooperative Extension has sometimes seen increases in the incidence of iron bacteria in stream inlets and around the periphery of lakes.  The iron is in the soils naturally, but when the water levels are elevated, there is more exposure to iron containing materials that can leach into the lakes and streams.

Our Weed Watch Patrol will be keeping an eye on this, as will the water sampling program.