Marine plastic pollution

Plastic pollution is ubiquitous throughout the marine environment, yet estimates of the global abundance and weight of floating plastics have lacked data, particularly from the Southern Hemisphere and remote regions. Here we report an estimate of the total number of plastic particles and their weight floating in the world's oceans from 24 expeditions (2007-2013) across all five sub-tropical gyres, coastal Australia, Bay of Bengal and the Mediterranean Sea conducting surface net tows (N??680) and visual survey transects of large plastic debris (N??891). Using an oceanographic model of floating debris dispersal calibrated by our data, and correcting for wind-driven vertical mixing, we estimate a minimum of 5.25 trillion particles weighing 268,940 tons. When comparing between four size classes, two microplastic <4.75 mm and meso- and macroplastic >4.75 mm, a tremendous loss of microplastics is observed from the sea surface compared to expected rates of fragmentation, suggesting there are mechanisms at play that remove <4.75 mm plastic particles from the ocean surface.
Plastic pollution is globally distributed across all oceans due to its properties of buoyancy and durability, and the sorption of toxicants to plastic while traveling through the environment have led some researchers to claim that synthetic polymers in the ocean should be regarded as hazardous waste, Through photodegradation and other weathering processes, plastics fragment and disperse in the ocean converging in the subtropical gyres.
Generation and accumulation of plastic pollution also occurs in closed bays, gulfs and seas surrounded by densely populated coastlines and watersheds.<ref name=plos-afloat/>
The impact of plastic pollution through ingestion and entanglement of marine fauna, ranging from zooplankton to cetaceans, seabirds and marine reptiles, are well documented, Adsorption of persistent organic pollutants onto plastic and their transfer into the tissues and organs through ingestion is impacting marine megafauna as well as lower trophic-level organisms and their predators. These impacts are further exacerbated by the persistence of floating plastics, ranging from resin pellets to large derelict nets, docks and boats that float across oceans and transport microbial communities, algae, invertebrates, and fish to non-native regions, providing further rationale to monitor (and take steps to mitigate) the global distribution and abundance of plastic pollution.<ref name=plos-afloat/>

Main Menu

See Also

Main Menu