Boops boops as a bioindicator of microplastic pollution along the Spanish Catalan coast

Abstract Microplastic pollution is a growing cause of concern for the marine environment, particularly in the Mediterranean Sea, which is considered to be one of the most polluted seas worldwide. In this study, the gastrointestinal tracts of 102 bogues (Boops boops), sampled from three areas off the Catalan coast (Spain) subject to different degrees of industrialization, were analysed to assess microplastic ingestion and thus estimate local levels of microplastic pollution. Microplastics were detected in 46% of samples analysed. As expected, the abundance and frequency of occurrence of ingested microplastics were higher off the most anthropized area of Barcelona. The majority of ingested microplastics were blue fragments ranging 0.1–0.5 mm, and the most common polymer type was polypropylene. The results of this study indicate the area off Barcelona as a possible area of concentration for microplastics, further supporting the use of B. boops as a bioindicator to assess microplastic pollution.