The Mariana Trench, the deepest known part of the ocean, was once imagined as a place largely untouched by human activity. The discovery of a plastic bag on its seafloor challenged that idea, showing that plastic pollution can reach even the most remote marine environments. Despite its extreme depths, the trench supports diverse marine life, including corals, jellyfish, and deep-sea octopuses.

Single-use plastics are a major part of the problem, with disposable bags and packaging entering the ocean through rivers, wind, runoff, and other pathways. According to the Deep-Sea Debris Database, nearly 89% of plastic recorded in the Mariana Trench is single-use. Marine animals can also interact with plastic through ingestion or entanglement, creating additional risks for vulnerable deep-sea ecosystems.

Ocean plastic comes from both land and sea, with much of it ultimately reaching the water through rivers and coastal systems. Discarded fishing gear also contributes to large concentrations of marine debris, while plastic gradually breaks down into smaller particles and microplastics that can settle on the seafloor. The plastic found in the Mariana Trench highlights how widespread the pollution problem has become and the importance of reducing plastic waste and protecting marine environments.