Steev,
Looks like a zooplankton bloom to me. It's always present in warm fertile water, but sometimes it spikes.
When weather is hot and winds are calm, it creates a surface film. Rain and wind will mix it with the water, and you don't notice it as much.
Aeration will help keep it stirred up locally, but you'll still get floaties around the edges. If your pond is no more than 7-8' deep, sudden aeration won't likely hurt anything. But then, aeration isn't as beneficial in a shallow pond anyway. If your pond is deep, be careful as was already mentioned.
Keeping fertile runoff and dead grass/weeds out of the water removes some of the plankton's food, and should reduce it somewhat.
