Pelagic shark intestine as a potential temporary sink for plastic and non-plastic particles

Highly migratory pelagic sharks have the potential to serve as carriers of particle contamination in a vast three-dimensional space. We investigate the occurrence, abundance and characteristics of plastic and non-plastic particles in the scroll intestine of the blue shark (Prionace glauca), one of the most abundant pelagic shark species worldwide. We detected both plastic and non-plastic particles in all sections of the intestine, with the posterior region exhibiting the highest concentration. We estimated that individual intestine may contained 11.21 ± 9.62 and 48.00 ± 23.90 plastic or non-plastic particles, respectively. Fibers dominated particle morphology (95.58%), primarily composed of plastic polymers (polyester and polyethylene terephthalate) (plastic) and non-plastic material (rayon and cotton). Given their size range (102.08-8113.54 μm), these particles are likely to be released into the water column through excretion. The intestine of P. glauca may act as a temporary particle sink, a phenomenon potentially common among pelagic sharks worldwide. This study provides new insights for the role of highly migratory fish species in the transport and distribution dynamics of marine particle contamination.