Microplastics in the Canary Islands: a case study on transport and tourist pressure

Abstract

Microplastics (MPs) are a global concern due to their persistence and capacity to adsorb and transport pollutants. The Canary Islands, influenced by the Canary Current, are particularly vulnerable to MPs accumulation from remote sources. The European Union’s Watch List includes emerging contaminants that require monitoring to assess potential ecological risks, though limited data hinder definitive evaluations. This study conducted a monitoring campaign between December 2023 and September 2024 across eleven beaches on four eastern islands of the archipelago. The aim was to assess MPs pollution (particles between 1 and 5 mm) and the presence of 26 organic contaminants from the EU Watch List adsorbed onto MPs, evaluating seasonal variation and tourism influence. Results show that beaches facing north and east had significantly higher MPs levels—up to an order of magnitude greater (ranged from <10 to >500 items/m2)—due to strong wind exposure, confirming the role of the Canary Current in MPs transport. White/transparent fragments dominated (>50%) among MPs types. Eight Watch List compounds were identified, with UV filters—commonly found in sunscreens—being the most frequently detected, present at nearly all sampling sites. Octocrylene reached concentrations up to 17,811 ng/g in highly touristic beaches. These findings highlight the environmental pressure on insular coastal zones and the relevance of combining MPs monitoring with targeted contaminant analysis in regions affected by oceanic currents and tourism.