Eastern Pacific Reveals Abyssal Plastic Contamination and Coastal Trends

Although 28 studies worldwide have documented plastic debris on the deep-sea floor, only one has addressed the eastern Pacific margin. Equally uncommon are long-term beach monitoring programs that integrate debris counts with oceanographic and meteorological records. This study delivers the first combined evidence of abyssal contamination and a six-year coastal time series in the equatorial eastern Pacific, establishing a rare dual perspective on plastic transport and deposition across connected marine environments. In February 2024, the submarine NAUTILE completed 13 dives to depths >3 900 m along Ecuador’s continental margin, surveying debris across the shelf, slope, and abyssal trench. The survey covered >560 000 m² and 222 h of video, revealing degraded fishing gear at cold seeps and relatively intact bags, packaging, and bowls at depth, exhibiting a probable polymer composition dominated by polyethylene, polypropylene, and nylon. Approximate visual encounter estimates, the density of abyssal litter reached between 0.016 and 0.019 g/m². To contextualize these findings, a six-year dataset (2019–2025) from a fixed 100 m² beach station recorded 152.9 kg of debris, with an accumulation rate of 5.7 g/week/m². Oceanographic variables (temperature, wind, solar radiation, pH) were associated with transport, burial, and fragmentation processes, with food packaging and fishing gear dominant across depths. Notably, similar items (bags, food bowls, bottles, and nylon threads) were documented both on the beach and at abyssal depths, providing suggestive evidence of connectivity between coastal and deep-sea debris sources. Our study thus represents the first report of plastic pollution in the eastern equatorial Pacific abyss and highlights the need for integrated monitoring and policy frameworks that address marine plastic pollution across connected ecosystems.