Microplastics on National Park Beaches

Guest post By:  Stefanie Whitmire, Ph.D., Research Scientist at the Baruch Institute of Coastal Ecology & Forest Science, Clemson University

Microplastics are plastic pieces measuring less than five millimeters in size and in recent decades, there have been many studies that indicate a strong presence of this type of debris in marine and coastal environments.

Microplastics can come from a variety of sources. Some microplastics are manufactured at that small size as microbeads, found in products like toothpaste and facial scrubs, or pellets, which are used to make larger plastic items. Microfibers, another type of microplastic debris, come from synthetic items such as rope or clothing (like fleece).

Microplastics also come from the breakdown of larger plastic pieces, such as water bottles and fishing line. Unfortunately, the presence of microplastics in the marine environment poses risks to wildlife. Microplastics ingested by animals can physically damage the digestive tract and potentially expose the animal to chemicals and contaminants associated with the microplastic particle.

However, no clear patterns between quantity of microplastics and geographic features like urban centers or rivers were apparent. This was not completely unexpected given the wide geographic sampling and the numerous local factors that could influence microplastic abundance along these shorelines. For instance, beaches can capture microplastics from both open water bodies (the ocean or lakes) and riverine systems.

Additionally, beaches are dynamic systems, with constant movement of sand and other particles like shells, glass, and plastic. Understanding the movement and turnover of microplastics in beach environments will help us clarify the exposure and risk to wildlife in the future. Overall, this project provided a snapshot of microplastics around the United States and emphasized the pervasive nature of this type of marine debris.