It’s 7:48 pm on January 8, 2018, and rain is quenching San Mateo, California’s parched suburban streets. I park my car and don my waterproof jacket and pants, yank on knee-high plastic rain boots, and trudge over to Carolynn Box, science programs director for the 5 Gyres Institute, and Diana Lin, environmental scientist with the San Francisco Estuary Institute (SFEI). Standing on a footbridge over San Mateo Creek, we are all wrapped, head to toe, in foul weather gear — all of it plastic in one textile form or another. Box plunges a rigid plastic tube into the swiftly moving creek as Lin turns on a pump. Making a loud wamp-wamp-wamp sound, like a sewing machine, it slurps up a 5-gallon (19-liter) sample of water from the swiftly moving stream.
A passerby inquires what we’re up to. Someone quips, “We’re bottling water to sell it!” Everyone chuckles.
In fact, the creek sampling is part of a two-year research project in which SFEI and 5 Gyres are analyzing microplastics — synthetic fragments 5 millimeters (0.2 inches) or smaller — in water, sediment, fish and wastewater treatment plant effluent released into San Francisco Bay. This includes microfibers — thread-shaped microplastics — shed from synthetic apparel, like the clothes we are all wrapped in.
Animal Impacts
To date, laboratory studies have largely looked at microplastics as a whole rather than specifically at microfibers. However, since microfibers are a primary constituent of microplastics, such research can provide useful insights.
Lab studies have found that microplastics can harm small aquatic organisms that eat them — including plankton, a hugely important food source for aquatic organisms. These harms include decreased ability to feed and reproduce. Zooplankton given food laced with microplastics in a lab had decreased nutrition and poorer health than the control group. And pearl oysters fed polystyrene…