The Biofilm is Like a Waxy Crust

[Don Schaeffer]

The biofilm has become a thin waxy crust floating on the water surface. Unfortunately my efforts to draw a sample broke the surface and made it more like a lump, rather than a smooth flat crust. You can see occasional flashes of fast-moving protists crossing the camera and some essentially stationary protists floating inside sections of the broken waxy shell.

https://youtu.be/8yvM77oDm94