Freshwater zebra mussels deal with microplastics surprisingly well

The invasive species may hold lessons for others

Wikimedia (PD)

Microplastics are found in marine and aquatic environments worldwide because they are used in personal care products, and result from the breakdown of larger plastic waste. Many researchers, policy makers, and scientists in the the private sector are concerned about how microplastics affect the environment, ecologically and commercially important species, and human health. 

The effects of microplastics on freshwater species are less well-studied than those in marine species. In a study published in Environmental Toxicology, researchers from Goethe University, the Federal Institute of Hydrology, and the Norwegian University of Science and Technology tested zebra mussels found in a German lake for various signs of microplastic toxicity and connections between toxicity and physical traits. Zebra mussels are a freshwater mollusk native to Russia and Ukraine, that are now considered an invasive species in Europe and North America. The researchers also repeated some tests with duck mussels and Chinese pond mussels to compare the results. 

All three freshwater mussel species showed little impact from microplastics. For zebra mussels in particular, microplastic toxicity only affected their ability to filter algae for food. The researchers believe this happens as a result of their ability to filter out microplastic particles before ingesting them. Given the harsher impacts of microplastics on other animals, the team may study how the filtering is so effective in comparison to other shellfish, for instance.