A preliminary study on shape descriptors for the characterization of microplastics ingested by fish

In this study we investigate the reliability of shape descriptors in providing a more detailed characterization of microplastics ingested by fish. In particular, a new approach based on shape descriptors is compared with the traditional approach, in the explanation of speciesspecific selection mechanisms in the ingestion of MPs. In accordance with the traditional information available, the first question is whether the rate of ingestion depends on the species. Correspondence analysis was then performed to highlight possible differences in the types of MPs ingested by the three species in terms of shape categories, color and size classes. The traditional approach does not provide enough information on the selection mechanism of MPs. New quantitative shape descriptors were therefore used to identify a relationship between MPs characteristics and species. PCA technique and Kruskal-Wallis test were used.