Microplastics in wild mussels (Mytilus spp.) from the north coast of Spain

Microplastic content (MPs) in mussels (Mytilus spp.) from two areas of the north coast of Spain was measured for the first time. Additionally, a comparison of microplastic levels observed in mussels digested with nitric acid and with potassium hydroxide was carried out. The average microplastic concentration in mussels digested with nitric acid was significantly lower than that observed in mussels digested with potassium hydroxide (p<0.05). The average concentration of microplastics in mussels from the Cantabrian Sea (2.55 +/- 2.80 MPs g(-1) WW) was slightly higher than that in mussels from the Ria of Vigo (1.59 +/- 1.28 MPs g(-1) WW). Both in the Ria of Vigo and in the Cantabrian Sea the observed pattern of pollution was fitted to the one expected. Consequently, mussels have been confirmed as suitable sentinel organisms for microplastic pollution.