Global Distribution, Composition and Abundance of Marine Litter

Abstract

Marine debris is commonly observed everywhere in the oceans. Litter enters the seas from both land-based sources, from ships and other installations at sea, from point and diffuse sources, and can travel long distances before being stranded. Plastics typically constitute the most important part of marine litter sometimes accounting for up to 100 % of floating litter. On beaches, most studies have demonstrated densities in the 1 item m −2 range except for very high concentrations because of local conditions, after typhoons or flooding events. Floating marine debris ranges from 0 to beyond 600 items km −2 . On the sea bed, the abundance of plastic debris is very dependent on location, with densities ranging from 0 to >7700 items km −2 , mainly in coastal areas. Recent studies have demonstrated that pollution of microplastics, particles <5 mm, has spread at the surface of oceans, in the water column and in sediments, even in the deep sea. Concentrations at the water surface ranged from thousands to hundred thousands of particles km −2 . Fluxes vary widely with factors such as proximity of urban activities, shore and coastal uses, wind and ocean currents. These enable the presence of accumulation areas in oceanic convergence zones and on the seafloor, notably in coastal canyons. Temporal trends are not clear with evidences for increases, decreases or without changes, depending on locations and environmental conditions. In terms of distribution and quantities, proper global estimations based on standardized approaches are still needed before considering efficient management and reduction measures.

Enhancing public awareness and promoting co-responsibility for marine litter in Europe: The challenge of MARLISCO

“…While it corresponds to a very wide range of items with different origin, usage and composition, plastics consistently rank as the most abundant types of marine debris on a global scale (STAP, 2011;Galgani et al, 2015). European Regional Sea Conventions reports show that plastics account for 50-80% of litter items found on beaches (OSPAR, 2009;HELCOM, 2009;UNEP/MAP MEDPOL, 2008).…”

“…Plastics are not only ubiquitous in our daily lives but they are now found throughout the marine and coastal environment, from the poles to the Equator, from shorelines and the sea surface to the sea floor (Galgani et al, 2015;Thompson et al, 2009;Eriksen et al, 2014). Inadequate solid waste management, inappropriate waste disposal by consumers at large and discharge of inappropriately treated/untreated waste water can all lead to litter entering the sea but there is also direct input in the marine environment from maritime activities, coastal tourism and recreation (STAP, 2011;Barnes et al, 2009).…”

Micro-and macro-plastics in marine species from Nordic waters

“…Several reviews have been performed to assess the current state of knowledge worldwide (e.g. Galgani et al, 2015;GESAMP, 2015;GESAMP, 2016) and national and regional projects have attempted to highlight sources and sinks of plastic pollution (e.g. Hong et al, 2014;Sundt et al, 2014).…”

“…An ability to effectively compare studies utilising different methods is at the forefront of current research since there is an absence of comparable methods for microplastic and macroplastic studies (Lusher, 2015;Galgani et al, 2015). In addition, since microplastics do not behave and move as classical particle-bound environmental pollutants, and are not evenly distributed in the environment (Nuelle et al, 2014), it is a challenge to sample representative parts of different matrixes.…”

Plastic debris and policy: Using current scientific understanding to invoke positive change

“…In marine habitats, global plastic contamination has been reported in the pelagic area [4,18], in the deep sea [6], and stranded on coastlines [2]. Researchers have found plastic debris in a wide range of habitats, including estuaries [19], sandy beaches [2], seagrass beds [20], coral reefs [21], sea mounts [22], and even sea ice [23].…”