Size matters more than shape: Ingestion of primary and secondary microplastics by small predators

Abstract Experimental studies have shown how microplastics are taken up by various aquatic organisms. Most of these studies have been carried out with small (  200 μm and ABS > 100 μm) in comparison to primary microplastic beads (90 μm). Our results show that fragments of secondary plastics may end up in the food web but only in small amounts, and that the size of the fragments more than their shape is a crucial nominator influencing the numbers of plastics ingested. Future research aiming to resolve the effects of microplastics in the ecosystems should focus on environmentally relevant plastics and concentrations.