Marine litter is any solid manufactured or processed material – plastic, metal, wood, rubber, glass and paper – that ends up in the ocean. There are several ways for litter to reach the sea. It can be deliberately discarded or unintentionally lost on beaches, on shores or at sea. But it also can be transported by rivers, draining or sewage systems or winds.
By 2050, an estimated 99% of seabirds will have ingested plastic. Scientists say that marine litter harms over 600 marine species. Some of them eat it. Others become entangled in it and die.
Between 60 and 90% of marine litter is plastic.
In fact, plastic waste is one of the biggest threats to the world’s oceans, according to the United Nations Environment Programme (UNEP). At least 8 million tonnes of plastic leak into the ocean each year. In February 2017, UNEP launched the Clean Seas campaign with the aim of engaging governments, the general public, civil society and the private sector in the fight against marine plastic litter. Until 2021 it will address the root-cause of marine litter by targeting the production and consumption of non-recoverable and single-use plastic
Results, also with focus on single use products, have been provided in support to the development of the EU Plastics Strategy. The data analysis involved spatial-temporal data grouping at European, regional and national level, including also seasonal variability of beach litter. A total of 355671 marine litter items have been recorded during 679 surveys on 276 European beaches. The report gives a brief outlook on the potential consideration of risk-related item properties, leading to a prioritization based on potential harm. [Source: Top Marine Beach Litter Items in Europe report]
Marine litter is a threat not only to marine species and ecosystems but also carries a risk to human health and has significant implications to human welfare, impacting negatively vital economic sectors such as tourism, fisheries, aquaculture or energy supply and bringing economic losses to individuals, enterprises and communities.
For an insight about the major negative impacts from marine litter and the mechanisms of harm, see the EU technical report Harm caused by Marine Litter.
A given site or region can be subject to litter pollution from a number of sources, which can be local, regional or even distant, as litter can be transported to a specific area by ocean currents and wind drift. For this reason, pinpointing the origin of the different items that make up marine litter is a difficult task and will always have an inherent degree of associated uncertainty.
Plastic food packaging recorded in the marine environment, for example, can consist of a diverse selection of items, which can be generated from a number of sources, which in turn can be sea-based or land-based and originate from near or distant regions.
A wide variety of methods have been used over the years to determine the sources of marine litter, from simple counts of items believed to originate from a given source to more complex statistical methods.
For an overview of the main methods used for determining sources of marine litter, see the EU technical report Identifying Sources of Marine Litter