Anthropogenic fibers in the Mediterranean sea: Methods and monitoring of an overlooked category of microparticles in the water column

Anthropogenic particles (APs) are widespread in the marine environment, but knowledge gaps remain regarding anthropogenic fibers. This study aimed to evaluate the presence of APs, including natural and synthetic fibers, in the water column. A literature review on fibers in Mediterranean seawater revealed that current sampling methods are underdeveloped. Two sampling methods were compared to determine the best approach for collecting fibers: a new in-situ pump (20 μm mesh filter) and a WP2 plankton net (200 μm). The in-situ pump was the most effective method and was applied in three areas of the Western Mediterranean Sea (Gulf of Asinara, Capraia Island, Capo Carbonara). The predominant APs, characterized by μFTIR, were cellulose and polyester fibers, reflecting the global textile fiber production. The Asinara area was the most impacted area (average of 393.7 items/m³). This study highlights the ubiquitous presence of fibers in the water column and underscores the need for further investigation of potential impacts on marine biota.