I can't really give you answers on this with any confidence. Bill refers to Kasco, but is it surface or bottom diffusers? I am assuming surface aerator for this case. But a bottom diffuser may be a good option for you in the long term. Some links here:
http://www.pondboss.com/resource_guide.asp?id=13&c=1http://kascomarine.com/products/pond-lake-aerators/af-series-surface-aerators/I am starting to experience a little bit of this myself, but the pond is 1500' from any electric. I assume the surface agitator is run directly from a electric line, not air line. I wonder if a generator would run it for short periods when it is only needed. I am also pondering the idea of setting my trash pump to act in some similar way.
Also a link with Bills comment on 8/18 to get rid of it:
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=454383#Post454383