Microplastic contamination and risk assessment in blue shark (Prionace glauca) from the eastern tropical Pacific Ocean

We quantified the abundance and characteristics of microplastics in the blue shark, Prionace glauca, found in the eastern tropical Pacific Ocean and investigated the potential microplastic pollution risks. Microplastics (MPs) were detected in 39.1 % of specimens, up to 0.15 +/- 0.38 items/g wet weight of the posterior part of the pylorus, and were sized 45.87 to 3220.12 mu m. The majority were fibrous in shape (83.3 %) and blue in color (72.2 %). Both sexes of sharks had similar MP abundance and characteristics, except for polymers, with polyethylene terephthalate and polypropylene representing the dominant type in males and females, respectively. Most in-dividuals experienced low pollution, but one male P. glauca exhibited a high ecological risk level owing to the high MP abundance and detection of polyvinyl chloride. This study provides an important baseline for the ingestion of microplastics by pelagic shark species and is a preliminary quantitative measure that could be used in future studies of the risk of MPs.

Automated summary

This study quantified the abundance and characteristics of microplastics in blue sharks found in the eastern tropical Pacific Ocean and investigated the potential pollution risks. Most individuals had low levels of microplastic ingestion, but one male blue shark showed a high ecological risk due to high microplastic abundance and detection of a specific type of plastic.