Toxic effects of pristine and aged polystyrene microplastics on selective and continuous larval culture of acorn barnacle Amphibalanus amphitrite.

This study evaluates the toxicity of pristine (Unwashed) and aged, clean (Biofilm-) or fouled (Biofilm+), PS microspheres (3 mu m,10 mu m), using Washed particles as a reference material, on selective and continuous larval culture of Amphibalanus amphitrite. Exposure to 3 mu m Unwashed and Biofilm+ particles for 24 h induced significant mortality (60 % and 57 % respectively) in stage II larvae. Stage II and VI nauplii showed greater uptake of 3 mu m Biofilm- particles. Accumulative exposure to microplastics in continuous larval culture significantly affected the naupliar survival, particularly of stage III and IV. Cumulative mortality was > 70% after exposure to 3 mu m Unwashed and 10 mu m Biofilm+ particles. Unwashed particles with increasing concentration and aged particles with increasing size, delayed the development of nauplii to cyprids. Though,> 50% cyprids showed successful settlement however the highest concentration of 3 mu m Biofilm+ microspheres inhibited the settlement and induced precocious metamorphosis in 9 % of the cyprids.