Marine plastic litter – A massive waste problem

The pollution of the oceans with anthropogenic and especially plastic litter is acknowledged as one of the major environmental stressors. Life cycle assessments of plastic products carried out to date have failed to take into account the fact that the oceans represent a final sink for plastics. At present, around 800 species have been shown to have negative interactions with marine litter, the majority relating to entanglement in and ingestion of plastic items. Additionally, marine litter causes socio-economic costs and may impact the wellbeing of society at large. The causes and sources are manifold and include insufficient producer responsibility, lack of awareness of the consequences of littering as well as poor sewage and waste management. Beside large items such as bags and bottles, the presence of microplastic particles sized 5 millimeter and smaller has also been verified in water bodies, sediments and marine organisms throughout the oceans of the world. Large garbage patches, where litter accumulates due to prevailing flow regimes have been verified in all large ocean currents. Plastics degrade very slowly in the marine environment due to physical, chemical and biological processes, and when they settle in sediments they may persist for centuries. The presence of marine litter is largely based on society´s prevailing production and consumption patterns. Meanwhile, this issue has gained increasing recognition in international and regional fora, as exemplified by the European Strategy for Plastics in a Circular Economy, various resolutions by the United Nations and Action Plans adopted inter alia by Regional Seas Conventions and the G7/G20. The challenge remains to take advantage of the current political momentum to effectively implement these Action Plans and further develop tailor-made solutions. Change can only be triggered by compiling solutions together with experts of important sectors such as from waste prevention and management and by spreading the knowledge through education at all levels and age groups.