Fate of Nanoplastics in Marine Larvae: A Case Study Using Barnacles, <i>Amphibalanus amphitrite</i>

The exposure of nanoplastics was investigated by observing their interaction with Amphibalanus amphitrite (commonly known as acorn barnacles). Poly(methyl methacrylate) (PMMA) and fluorescent perylene tetraester (PTE) dye were used to prepare highly fluorescent nanoplastic particles. At concentrations of 25 ppm, the PMMA particles showed no detrimental impact on barnacle larvae and their microalgae feed, Tetraselmis suecica and Chaetoceros muelleri. PMMA nanoplastics were ingested and translocated inside the body of the barnacle nauplii within the first 3 h of incubation. The fluorescent PMMA particles inside the transparent nauplius were tracked using confocal fluorescence microscopy. Subsequently, the nanoplastics were fed to the barnacle nauplii under two conditions—acute and chronic exposure. The results from acute exposure show that nanoplastics persist in the body throughout stages of growth and development—from nauplius to cyprid and juvenile barnacle. Some egestion of nanoplastics was observed through moulting and fecal excrement. In comparison, chronic exposure demonstrates bioaccumulation of the nanoplastics even at low concentrations of the plastics. The impacts of our study using PMMA nanoparticles exceeds current knowledge, where most studies stop at uptake and ingestion. Here we demonstrate that uptake of nanoparticles during planktonic larval stages may persist to the adult stages, indicating potential for the long-term impacts of nanoplastics on sessile invertebrate communities.