Microplastic pollution from pellet spillage: Analysis of the Toconao ship accident along the Spanish and Portuguese coasts

In December 2023, 25 tons of pellets were lost by the Toconao ship in the Northwest Atlantic Ocean in front of the Portuguese coast. In this work, a coastal stretch of 633 km in Asturias and Galicia (Spain) and Northern Portugal was investigated to assess pellets' concentration on 31 beaches. Field surveys were carried out in March 2024 and focused on sampling plastic pellets deposited along the shoreline. All the 7263 sampled pellets were characterized by size, degradation level, and color, while one subset was characterized by weight (40 % of the total) and another subset by polymer type (15 % of the total) using FT-IR spectroscopy. The results reveal that 94 % of the surveyed sites containing pellets, whereas the concentration values vary significantly among beaches, ranging from 0 to 40.3 pellets/kg_dw. By combining the accounted variables, it emerges that 48.0 % of the collected pellets can be linked to the Toconao spill.