Ingestion of microplastics by demersal fish from the Spanish Atlantic and Mediterranean coasts

• Microplastic ingestion was studied in three demersal fish species from the Spanish coasts.
• The highest abundance of microplastics (33.3%) was found in red mullets from the NW Mediterranean.
• Dogfish from the Cantabrian coast and the Gulf of Cadiz averaged 20.8% stomachs with microplastics.
• These species may be suitable candidates for monitoring spatial and temporal trends of ingested litter.
• The present work represents a baseline study for the implementation of the MSFD descriptor 10 in Spain.

Microplastic pollution has received increased attention over the last few years. This study documents microplastic ingestion in three commercially relevant demersal fish species from the Spanish Atlantic and Mediterranean coasts, the lesser spotted dogfish Scyliorhinus canicula, the European hake Merluccius merluccius and the red mullet Mullus barbatus. Overall 212 fish were examined, 72 dogfish, 12 hakes and 128 red mullets. The percentage of fish with microplastics was 17.5% (15.3% dogfish, 18.8% red mullets and 16.7% hakes), averaging 1.56 ± 0.5 items per fish, and the size of the microplastics ranged from 0.38 to 3.1 mm. These fish species are used currently as biomonitors for marine pollution monitoring within the Spanish Marine Pollution Monitoring Programme (SMP), and may be as well suitable candidates for monitoring spatial and temporal trends of ingested litter. The data presented here represent a baseline for the implementation of the Marine Strategy Framework Directive descriptor 10 in Spain.