Mr willy - I commonly see foam similar to this on other waters; streams and ponds. I think it is due to abundant dissolved and or suspended proteins in the water combined with agitation of the water. The foam forms from wind action or surface agitation that causes the proteins to collect as foamy material. Cool temperatures may cause the foam to form more easily. Protein skimmers are often used in the intensive aquaculture (indoor) industry and by aquarium hobbists to produce this type of foam in their fish tanks. A search of protein skimmers may tell you more about dissolved proteins in the water. Sometimes I look at it microscopically to make sure that it is not something other than what I described above.


aka Pond Doctor & Dr. Perca Read Pond Boss Magazine -
America's Journal of Pond Management