Ingestion and transfer of microplastics in the planktonic food web
Experiments were carried out with different Baltic Sea zooplankton taxa to scan their potential to ingest; plastics. Mysid shrimps, copepods, cladocerans, rotifers, polychaete larvae and ciliates were exposed to; 10 mmfluorescent polystyrene microspheres. These experiments showed ingestion of microspheres in all; taxa studied. The highest percentage of individuals with ingested spheres was found in pelagic poly-; chaete larvae, Marenzelleria spp. Experiments with the copepod Eurytemora affinis and the mysid shrimp; Neomysis integer showed egestion of microspheres within 12 h. Food web transfer experiments were; done by offering zooplankton labelled with ingested microspheres to mysid shrimps. Microscopy ob-; servations of mysid intestine showed the presence of zooplankton prey and microspheres after 3 h in-; cubation. This study shows for the first time the potential of plastic microparticle transfer via planktonic; organisms from one trophic level (mesozooplankton) to a higher level (macrozooplankton). The impacts; of plastic transfer and possible accumulation in the food web need further investigations.