Assessing the presence and concentrations of microplastics in the gizzards of Virginia waterfowl

by Thomas Bustamante

Faculty Advisor: Dr. Andrew Dolby

Microplastics are defined as plastic fragments that are smaller than 5mm. These particles have become a ubiquitous water pollutant in recent years. While a substantial amount of research on their impacts on marine ecosystems has been conducted, the effect of microplastics on freshwater food webs remains poorly understood. In this study, we assessed the presence and concentrations of microplastic particles in the gizzards of the Canada Goose (Branta canadensis), Ring-necked Duck (Aythya collaris), Long-tailed Duck (Clangula hyemalis), Bufflehead Duck (Bucephala albeola), and Mallard (Anas platyrhynchos) hunted in the Piedmont and Coastal Plain of Virginia. Gizzards were bisected and had their contents removed for analysis. Collected gizzard contents underwent density separation in order to separate plastics from the sediment within gizzards. Isolated particles were then visually inspected under a dissecting microscope. Preliminary results show that with contamination taken into account, 90% of birds sampled contain microplastic fibers in their gizzards. These range in concentration from about 0.08-11.49 fibers/gram of gizzard material. All plastics were secondary fibers, meaning they originated from larger plastics that broke down over time. This provides further evidence that waterfowl not only ingest microplastics, but retain them in their digestive systems. Infrared spectroscopy was done on one fiber; it was determined to be polyethylene. As we move forward, we plan to incorporate chemical digestion and a more efficient chemical analysis in our methods. Further studies will also examine microplastic spatial distributions, as well as microplastics in the intestinal lining and lumen of these birds. This work will be able to help us understand the threat microplastics pose to organisms and ecosystems, as well as help us understand their geographic distributions.

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5 Replies to “Assessing the presence and concentrations of microplastics in the gizzards of Virginia waterfowl”

  1. Because I played an unbiased role in this, I have to say that this study is a very unique one. Most of the time when we talk about microplastics and birds, we’re usually looking at marine birds and don’t tend to think about freshwater avian species or bring them into the mix. However as we can clearly see from this work, like marine birds, freshwater birds are impacted by the presence of microplastics as well. It seems that the concentration of microplastics found along the coasts has more of a long-term negative impact on local birds there more-so than they have on freshwater fowl. We’ve all seen the numerous photos of deceased coastal birds with tons of plastics in their bodies, so the lack of this with freshwater birds and the fact that all of the birds in this study were killed directly from hunting makes me believe that the accumulation of microplastics inland is far less than on the coasts. This connection between birds and microplastics makes me even more curious about the creation and movement of microplastics around the environment.

  2. It was wonderful to see a presentation of your hard work, Thomas! I am looking forward to more in person presentations from you.

  3. Thank you Thomas for sharing your research. Your study demonstrates the widespread impact of micro plastics on the environment and wildlife.

  4. Great job putting all of this together Thomas! I look forward to seeing the data on how these plastics affect the more distal parts of the GI tract.

  5. Interesting (and slightly scary) material. Thanks for sharing your work with us. Best wishes,

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