Efficacy of freshwater pearl mussel (Lamellidens marginalis) as a biomonitoring tool for assessing microplastic pollution

The presence of microplastics (MPs) is an emerging concern for aquatic life. The present study investigated the ingestion and absorption of experimental MPs in the internal organ and body tissue of freshwater pearl mussel (Lamellidens marginalis) following exposure for 10 days and using histological procedures. Mussels were exposed to three types of bright color plastics were used such as plastic rope fibers, green PET bottle fragments and brush bristles. A reference group not exposed to MPs was also included. Following exposure, tissues were dissected and embedded in paraffin, and histological sections were examined for the presence of microplastic. Result showed that 31.25% of all the exposed mussels exhibited the ingestion of MPs. Fiber was the highly accumulated MPs followed by filaments. However, none of the mussels showed the ingestion of brush bristles. Accumulation of MPs was the highest for smaller sized categories. Histological observation of mussel’s tissue was also showed the absorption of MPs. The present experiment strongly suggests that the uptake, presence, and potential health impacts of MP should be closely monitored using L. marginalis as bio-monitor organism.