Plastic ingestion of endemic elasmobranchs of the Humboldt Current Large Marine Ecosystem

Plastic pollution is becoming more frequent in marine ecosystems, increasing its availability for ingestion by marine megafauna. We sought to evaluate the ingestion of plastics by three species of elasmobranchs endemic to the Humboldt Current Large Marine Ecosystem (HCLME). We analysed the digestive tracts of the humpback smoothhound Mustelus whitneyi (n = 128), Chilean eagle ray Myliobatis chilensis (n = 115) and Peruvian eagle ray Myliobatis peruvianus (n = 79), finding a total of 792 plastic particles (macro, meso and microplastics). M. peruvianus was the species with the highest prevalence of plastic particles (68 % individuals), while M. chilensis was the species with the highest abundance of plastic items per individual: 3 ± 6 (max: 44). Likewise, larger individuals of M. whitneyi (>80 cm body length) had a greater abundance of ingested plastic particles. The three species showed greater abundances of ingested plastics in the cold season (June - November). Almost 87 % of the total plastic particles recorded were fibres and the most representative types of polymers identified were anthropogenic cellulose, polyacrylamide, resin and polyethylene. Furthermore, the abundance of plastics by colour was correlated with certain prey items, which varied among the three species evaluated. These species, which inhabit benthic-demersal and pelagic coastal ecosystems are vulnerable to plastic ingestion, with possible trophic transfer through their prey, that could represent an additional risk for their populations and for the HCLME.