Mussels Excreting Microplastics May Help Clean the Ocean

In fighting one of the most elusive pollutants in our oceans, scientists have found an unexpected ally: the blue mussel (Mytilus edulis). Science reports that this hungry little filter-feeding mollusk isn't just impervious to the trillions of microplastics littering the Earth's oceans; it may hold a solution to mitigating pollutants' impacts. Microplastics, particles less than five millimeters, are challenging to clean up because they are so tiny and pervasive across most marine ecosystems, posing a real threat to marine life and, potentially, to human health. However, as the NOAA has discussed in a podcast, blue mussels are known to ingest these microplastics alongside their regular diet, holding them inside feces that is easier to filter out of the water.

Recent studies have affirmed the capabilities of blue mussels to filter microplastics from their environment—which a World Economic Forum article affirms doesn't harm the creatures—both in lab settings and real-world conditions. In the lab, mussels consumed up to two-thirds of the microplastics in their tanks, holding them in their feces. Additionally, mussels tested in a nearby marina demonstrated similar effectiveness in the wild, filtering as many as 240 microplastic particles per day. The lab results suggest that mussels could potentially remove an even greater quantity of microplastics with higher concentrations in the water. That's about a quarter million particles per hour.

While this discovery is promising, experts caution that using mussels as a standalone solution to microplastic pollution might not be feasible. Estimates say that it could take millions of mussels filtering 24 hours per day to impact the water in just a single bay. Furthermore, maintaining a balanced ecosystem restricts the number of mussels that can be introduced to an area at any time. Still, there is potential for the microplastics captured in mussel poop to become trapped in seafloor sediment, posing less risk to marine life.One major takeaway from this research is that while mussels might help mitigate microplastics' impact, the ultimate solution lies in stopping plastic pollution at its source. (More microplastics stories.)