Accumulation of Microplastic on Shorelines Woldwide: Sources and Sinks

Abstract

Plastic debris <1 mm (defined here as microplastic) is accumulating in marine habitats. Ingestion of microplastic provides a potential pathway for the transfer of pollutants, monomers, and plastic-additives to organisms with uncertain consequences for their health. Here, we show that microplastic contaminates the shorelines at 18 sites worldwide representing six continents from the poles to the equator, with more material in densely populated areas, but no clear relationship between the abundance of miocroplastics and the mean size-distribution of natural particulates. An important source of microplastic appears to be through sewage contaminated by fibers from washing clothes. Forensic evaluation of microplastic from sediments showed that the proportions of polyester and acrylic fibers used in clothing resembled those found in habitats that receive sewage-discharges and sewage-effluent itself. Experiments sampling wastewater from domestic washing machines demonstrated that a single garment can produce >1900 fibers per wash. This suggests that a large proportion of microplastic fibers found in the marine environment may be derived from sewage as a consequence of washing of clothes. As the human population grows and people use more synthetic textiles, contamination of habitats and animals by microplastic is likely to increase.

Plastic ingestion by estuarine mulletMugil cephalus(Mugilidae) in an urban harbour, KwaZulu-Natal, South Africa

“…Potentially, therefore, rates of ingestion may be similar to those found in urban environments. Fibres are probably derived from clothing and other synthetic textiles, because fibres found in marine environments around the world closely resemble those found in washing machine effluent and have the potential to pass through sewage treatment works (Browne et al 2011). Other sources of fibres found in the harbour may include weathered fishing and boat-mooring equipment (Guastella and Smit 1994;Murray and Cowie 2011).…”

“…Single use of plastics by modern society has added to the contamination of the global marine environment (Browne et al 2011). The presence of plastic in the environment facilitates the interaction with plastic by organisms, and the potential for its ingestion.…”

Fate of Microplastics in the Marine Isopod Idotea emarginata

“…Various studies demonstrated the presence of microplastics in the North Sea with maximum concentrations of up to 86 fibers·kg −1 sediment (dry weight) in subtidal habitats. 5,9,[17][18][19]21,22 Especially zones of low hydrodynamic action or dense macroalgal cover can reduce the water turbulence and thereby enhance deposition and sedimentation of particulate matter. 15,56 Additionally, Fucus canopies create a complex surface where plastic particles and fibers could stick to or get trapped.…”

“…5,20−22 Reported concentrations of microplastics in subtidal marine habitats range from 3.7 particles·kg −1 to 124 particles·L −1 of sediment. 5,17,23 Due to their size microplastics can be ingested by a wide range of organisms including fish larvae and small invertebrates which, in turn, are a food source for many other marine organisms. 5,7,9,24 At least 32 marine invertebrate species including pelagic (e.g., copepods and euphausids) and benthic representatives (e.g., mussels, lobsters, and polychaetes) have been reported to ingest microplastics.…”

Sorption of pharmaceuticals and personal care products to polyethylene debris

“…In the environment, larger plastic items can slowly breakdown into small pieces via physical, chemical, and biological processes (O'Brine and Thompson 2010;Singh and Sharma 2008). Plastic debris can be transported into oceans with current and accumulate in marine habitats (Browne et al 2011;Sadri and Thompson 2014;Thompson et al 2004). Plastic debris observed in the environment are mainly millimeters or smaller in size, and those less than 5 mm are generally referred to microplastics (Hidalgo-Ruz et al 2012; Thompson et al 2004).…”