I can see plastic everywhere now– and not just the
water bottles on the side of the trail or the plastic bags in branches, but the
tab you pull off of a disposable squirt bottle and the tiny corner torn off of
a granola bar. The most visually impactful part of this summer has been picking
through fully processed microplastic samples as we work to quantify just how
much plastic pollution is present in the Potomac River and the streams that
feed into it.
Microplastics are pieces of plastic, either fragmented
or intentionally produced, that are between 5mm and 0.3mm in diameter and are
the center of increased media and academic attention. My lab partner and I have
spent this summer studying these small bits of plastic in local waterways
hoping to build off of the work of Mason PhD student Doreen Peters and the
published work of Yonkos et al. (2015) who reported on microplastic in the
Chesapeake Bay. Despite the work of both scientists, no data has been published
on the presence, abundance, or concentration of microplastics in the Potomac
River. This is where Han and I enter the scene.
Most microplastics research focuses on those plastics
found floating at the surface of aquatic environments using a buoyant net named
after its look-alike a Manta Ray. Using one of these Manta nets housed at the
Potomac Science center, we’ve sampled Hunting Creek in Alexandria, VA; Gunston
Cove in Woodbridge, VA; and the Anacostia River in Washington, DC. However, we
also have used a novel stream sampling approach that uses a round-mouthed net
anchored to either side of a stream and left for an hour to passively collect
microplastics. Our lab’s principle investigator, Dr. Foster, and I sampled
Accotink Creek, Cameron Run, and the Northeast Branch of the Anacostia River
using our self-engineered technique. Finally, in an attempt to see if there is
movement of microplastics into the food web, we extracted and analyzed the
digestive tracts of four catfish.
Through this project, I hope to have some idea of an
ideal sampling method that is representative of the who ecosystem a researcher
is investigating, whether it is surface water sampling, sediment sampling, or
fish-gut analysis. Also, am testing whether these sites differ in each of those
sampling methods, and if so, what contributes to those differences. We have
just finished our sample processing, which involved hours of drying samples,
chemical digestion, picking at and counting plastics under a microscope, and
finally I will have a chance to crunch our numbers and test these hypotheses.
Looking back, I thought I would know what to expect
with this summer: sampling, processing, analysis, etc, however, I’ve learned
that each research experience is unique and rewarding in its own way. First of
all, becoming familiar a with a completely new and ever-growing field of
literature has been an exciting challenge. Also, working with old and new faces
in the lab and in the field, I have learned that all PIs and lab partners are
different and that relationships and expectations are always… plastic.
