We have noticed an oily looking sheen in our lake in places, especially noticeable where the water has receded (a scheduled lowering for dam repairs).
I sent a sample to the D.E.P. and their analysis confirmed it to be a cyanobacteria called Dolichospermum, a natural, nontoxic cyanobacteria that helps decompose vegetative material. It's a biofilm, common in productive (nutrient rich) lakes, and can lead to scum formation. This one belongs to the family Nostocaceae. They are more commonly referred to as nostoc bacteria.
It also presents on the waters' surface like metallic looking dots that float elusively on the water.
It's definitely not pollen at this time of year, and it doesn't seem to be a pollutant either - it disperses when agitated, but does not reform.
I sent a sample to the D.E.P. and their analysis confirmed it to be a cyanobacteria called Dolichospermum, a natural, nontoxic cyanobacteria that helps decompose vegetative material. It's a biofilm, common in productive (nutrient rich) lakes, and can lead to scum formation. This one belongs to the family Nostocaceae. They are more commonly referred to as nostoc bacteria.
Nostoc bacteria (found both terrestrially and in freshwater systems) photosynthesize, and have biotechnological uses, either as "biofertilizer or as a source of fatty acids for biofuel production." (Nostoc bacteria) They are a byproduct of cell and tissue breakdown when an organism decomposes.
Poor cyanobacteria! They get such a bad rap in the press when a toxic bloom from that genus is detected. Not everything that is a cyanobacteria is toxic - SOME species are, but not all. Cyanobacteria is a generic name, that refers to its color.
It's a form of recycling! Nothing to worry about. Something to learn about.