Electron microscope image of plastic microfiber (centre) in a filtered estuarine water sample from the UK, with suspended sediment particles (background) and estuarine plankton (diatoms, foreground). Source: Zachary T. Anderson, Andrew B. Cundy, Ian W. Croudace, Phillip E. Warwick, Omar Celis-Hernandez & Jessica L. Stead (2018) A rapid method for assessing the accumulation of microplastics in the sea surface microlayer (SML) of estuarine systems. Scientific Reports, 8:9428, DOI:10.1038/s41598-018-27612-w. https://creativecommons.org/licenses/by/4.0/.