Mysterious Microfibers

May 07, 2019

By Anna Bolm

Though this is my third cruise sampling the NCC for microplastic contamination in seawater and zooplankton, it is the first time I've seen anything like this!

Multiple microfibers collected in plankton tow. Photo: NOAA Fisheries

These red fibers were spotted in a vertical net sample, 65 nm off Newport. I typically only find a few potential microplastics at a time in any sample, so I was surprised to see such a high concentration of fibers. We took a scoop to check it out under the microscope right away. Microplastics are defined as plastics smaller than 5 mm in size and are identified under a microscope by lack of cellular structure, uniform thickness, and homogeneous color. These fibers fit the bill, but there were just so many! Most plastics are somewhat flexible and won't break when prodded. I poked one of the fibers and it broke in two, which means I would normally not count it as a potential plastic. The phytoplankton and zooplankton specialists on board were equally stumped. I put them under the compound scope for a closer look.

A closer look under the compound scope. Photo: NOAA Fisheries

What could they be?! The only way to truly find out is to send them out for Fourier transform infrared spectroscopy (FTIR) or Raman spectroscopy analysis.

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Last updated by Northwest Fisheries Science Center on March 02, 2020