Bio station scientists learn more about microplastics in Flathead Lake

Thanks to an Flathead Lake Biological Station study, scientists now have a greater understanding of the amount of microplastics polluting Flathead Lake, the likely sources of these microplastics, and what can be done to prevent more from finding their way into the lake’s world-renowned pristine water.

Published in the scientific journal Environmental Pollution, this microplastics study was led by Flathead Lake Biological Station visiting researcher Dr. Xiong Xiong from the Chinese Academy of Science’s Institute of Hydrobiology with support from Flathead Lake Biological Station director Jim Elser and Flathead Lake Biological Station research scientist Tyler Tappenbeck.

Through the study, Xiong identified three main ways that microplastics reach Flathead Lake.

One way is atmospheric deposition, where microplastics are transported to Montana from other more populated areas by the atmosphere via wind and clouds, and then fall into Flathead Lake, either directly from the air or through snow and rainfall.

At the mouth of the Flathead River, the biggest source of microplastics is most likely from plastic waste disposal.

Although landfills located in the Flathead Watershed are not open pit, microplastics are mobilized through water that picks up contaminants and via the soil of the landfill when winds carry away dust.

In more populated shoreline areas of the lake, researchers found that concentrations of microplastics were especially high.

In addition to plastic packaging, many of today’s clothes are made from fibrous plastics. These synthetic fabrics break apart on a microscopic level during washing, and are then transported and deposited into our waters through home septic systems and community water treatment plants.

Plastic waste from other human activities is also worthy of attention.

Though the levels of microplastics in Flathead Lake are relatively low, they are concerning. However, researchers are quick to point out that much can be done to reduce their presence in Montana’s waters.

Fibrous microplastics can be reduced by improving laundry practices and wastewater treatment, or by reducing the use of synthetic fiber material in favor of natural fiber clothing and materials.

Further strengthening disposal measures for plastic waste by both residents and visitors could also greatly help reduce microplastic contamination in Flathead Lake.

When it comes to reducing atmospheric microplastic deposition, researchers say extensive solutions are needed. Flathead Lake will remain at risk from microplastics arriving by air until global measures can be taken.