Impact of microplastic leachates on the anti-predator behaviour of the intertidal limpet: Cellana nigrolineata

Abstract

The anti-predator behaviour of Cellana nigrolineata was assessed in laboratory-controlled conditions in response to the presence of the whelks Reishia clavigera and Tenguella musiva in natural seawater and in leachate solutions prepared from commercially available polypropylene (PP), polyethylene (PE), polyamide (PA) and polylactic acid (PLA) pellets. Our results first showed that C. nigrolineata used both chemosensory and contact cues to react to the presence of R. clavigera and T. musiva. The anti-predator response of C. nigrolineata was much stronger towards R. clavigera than T. musiva. We also identified a new escape behaviour of C. nigrolineata, which was able to climb on top of the predator shells before flying away. We subsequently showed that leachate solutions of three conventional polymers (PP, PE and PA) and one biosourced and biodegradable polymer (PLA) respectively inhibited and impaired the ability of C. nigrolineata to react to R. clavigera and T. musiva chemical cues. The anti-predator responses elicited by contact between the whelk foot and the limpet epipodial tentacles were both polymer- and species-dependent, with a similar effect of polymers and a stronger effect of PP and PE leachate solutions. Taken together, our results indicate that microplastic pollution is likely to affect non-lethal predator-prey interactions in a species- and polymer-specific fashion.