Report | July 15, 2020
Plastic in the deep: an invisible problem
Executive summary
Most marine debris remains hidden in the depths where, year after year, currents increase the concentration of waste, including macroplastics. Many estimates have been made of how long it takes for different plastic objects to degrade, but these approximations mainly relate to surface water. They are not valid for the deep seas, as these environments are characterised by a lack of sunlight, low temperatures, and limited erosion. For this reason, marine debris can disrupt these ecosystems for centuries before it eventually degrades.
Much of Europe’s waters are deep. Canyons, seamounts, escarpments, and reefs trap plastics, while simultaneously act as biodiversity hotspots. Observations made during Oceana’s expeditions show accumulations of single-use plastics in areas of high biological value, abandoned fishing gear in the middle of the ocean, and half buried sheets of plastic hundreds of metres below the surface.
Very often, recovering this debris is technically and economically unfeasible, either because it is located at a great depth or because it is snagged on fragile biological structures. Therefore, to reduce the damage, it is essential to drastically reduce the everyday use of plastic and avoid its uncontrolled dumping. Oceana calls on all social agents to reduce the irrational use of plastic and implement an ambitious regulatory framework that responds decisively to one of the greatest challenges posed by debris and plastic in the marine environment: the pollution of the deep sea.

