An image of diatoms colonizing polypropylene after 1 week incubation in the ocean. Note the green chloroplasts in the 'football shaped' diatom frustules (the cell walls made of glass stained red). Diatoms at such high coverage have the ability to make plastics sink due to their dense glass cell walls. Cellular DNA shows up as blue due to the stain the intercalates in between the DNA base pairs. The blue dotted lines are filamentous bacteria consisting of chains of cells, each blue dot represents a single cell with a bundle of DNA at the center. The scale bar is 20 microns in length.