A recent Nature publication has revealed that the levels of plastic pollution in freshwater ecosystems, such as lakes and reservoirs, surpass those observed in the renowned “garbage patches” of the ocean. Conducted by an international team of researchers, the study analyzed surface water samples from 38 lakes and reservoirs, consistently detecting the presence of microplastics.
The research, conducted by the Global Lake Ecological Observatory Network (GLEON), emphasizes that freshwater environments, including lakes and reservoirs, exhibit higher concentrations of plastic debris compared to oceanic garbage patches. The study attributes this concerning trend primarily to human activities, underscoring the vulnerability of densely populated areas and water bodies significantly influenced by human presence.
Every year, approximately 14 million tons of plastic find their way into the ocean. However, this study highlights that plastic intrusion extends beyond marine ecosystems.
“Our findings demonstrated the presence of microplastics in every lake we sampled,” stated Ted Harris, an associate research professor at the University of Kansas’ Kansas Biological Survey & Center for Ecological Research. “Even in seemingly pristine and picturesque vacation destinations, we discovered a clear connection between plastics and human impact.”
Harris, a member of the Global Lake Ecological Observatory Network (GLEON), collaborated with Rebecca Kessler, a recent graduate from the University of Kansas, to investigate two lakes in Kansas (Clinton and Perry) and the Cross Reservoir at the KU Field Station.
The research project, coordinated by the Inland Water Ecology and Management research group at the University of Milano-Bicocca, Italy, led by Barbara Leoni and Veronica Nava, encompassed the sampling of surface waters from 38 lakes and reservoirs across various geographical locations and limnological attributes. Plastic debris was identified in all bodies of water examined.
“This study essentially demonstrates that where there are more humans, there is a greater abundance of plastics,” noted Harris. “Lakes like Clinton Lake, with relatively low microplastic levels, owe it to their fewer human inhabitants compared to locations like Lake Tahoe, surrounded by human settlements. These seemingly pristine lakes are, in fact, major sources of microplastics.”
Harris also highlighted that seemingly innocuous items such as T-shirts contribute significantly to plastic pollution. “Microplastic fibers from clothing worn during activities like swimming easily spread throughout the environment,” he explained.
The GLEON study identifies two types of vulnerable water bodies prone to plastic contamination: lakes and reservoirs located in densely populated urban areas and those characterized by extended water retention times, elevated deposition areas, and substantial human influence.
“When we commenced this study, I didn’t fully comprehend the distinction between microplastics and larger plastic debris,” admitted Harris. “While the term ‘garbage patch’ conjures images of large bottles and such, it fails to account for the extensive amount of smaller fragments. Lake Tahoe, for instance, doesn’t exhibit a massive visible garbage patch, but it suffers from severe microplastic contamination. These microscopic plastic pieces, indistinguishable to the naked eye, become apparent under a 40,000x microscope, appearing as jagged particles similar in size to algae or even smaller.”
Harris and Kessler were particularly motivated to participate in this project to shed light on an often overlooked region in the United States. “In this study, our sampling location was the lone dot in the middle of the country,” Harris remarked. “Iowa, Missouri, and Colorado represent vast areas with numerous water bodies, yet they are frequently excluded from extensive global investigations. Hence, it was crucial for us to showcase Kansas and understand the disparities in our lakes within a broader context.”
Since 2013, Harris has been engaged in aquatic ecology research at the University of Kansas, while Kessler recently graduated from the institution with a degree in ecology, evolutionary & organismal biology.
Kessler emphasized the key takeaway from their study, stating, “The most significant finding is that microplastics are present in all lakes. Although concentrations may differ, they are undeniably ubiquitous. Human interaction with these lakes stands as the principal contributing factor to this microplastic pollution.”
Reference: “Plastic debris in lakes and reservoirs” published in Nature on July 12, 2023.
DOI: 10.1038/s41586-023-06168-4
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Frequently Asked Questions (FAQs) about microplastic contamination
Q: What did the study reveal about microplastic contamination in freshwater environments?
A: The study revealed that concentrations of microplastics in freshwater lakes and reservoirs are higher than those found in oceanic “garbage patches.” All 38 sampled water bodies showed the presence of microplastics, emphasizing the widespread contamination in these freshwater environments.
Q: What are the main contributing factors to plastic pollution in lakes and reservoirs?
A: The study identifies human interaction as the primary contributing factor to plastic pollution in lakes and reservoirs. Areas with high population density and significant human influence are particularly vulnerable to plastic contamination.
Q: How do microplastics enter freshwater ecosystems?
A: Microplastics enter freshwater ecosystems through various sources, including human activities such as swimming and the use of products containing microplastic fibers. These fibers can detach from clothing and other items and eventually find their way into lakes and reservoirs.
Q: Are microplastics only present in visibly polluted water bodies?
A: No, microplastics are found in all lakes, regardless of their apparent cleanliness. Even seemingly pristine and beautiful lakes can harbor significant levels of microplastic contamination, highlighting the invisible nature of this pollution.
Q: Are freshwater lakes and reservoirs more impacted by plastic pollution than the ocean?
A: Yes, according to the study, freshwater environments exhibit higher concentrations of microplastics compared to oceanic “garbage patches.” This highlights the urgent need to address plastic pollution in both marine and freshwater ecosystems.
Q: What regions were included in the study?
A: The study included 38 lakes and reservoirs from various geographical locations, covering areas with different levels of human influence and limnological characteristics. However, specific regions were not mentioned in the provided information.
More about microplastic contamination
- “Plastic debris in lakes and reservoirs” (Nature): Link
- Global Lake Ecological Observatory Network (GLEON): Link
- University of Kansas – Kansas Biological Survey & Center for Ecological Research: Link
- University of Milano-Bicocca – Inland Water Ecology and Management Research Group: Link
