From the BBC News

Dr Richard Thompson at the University of Plymouth researches what happens when plastic breaks down (degrades) in seawater

They have identified plastic particles of around 20 microns – thinner than the diameter of a human hair.
In 2004 their study reported the incidence of the particles had been increasing over the years.

They have found plastic particles smaller than grains of sand.

They estimate there are 300,000 items of plastic per sq km of sea surface, and 100,000 per sq km of seabed.

Thompson and his team conducted experiments on three species of filter feeders and found that the barnacle, the lugworm and the common amphipod or sand-hopper all  readily ingested plastic as they fed along the seabed.

They wanted to  establish if chemicals can leach out of degraded plastic and if plastic absorbs other contaminants such as PCBs and other polymer additives.

“The plastics industry’s response is that much of the research is speculative at this stage, and that there is very little evidence that this transfer of chemicals is taking place in the wild.It says it is doing its bit by replacing toxic materials used as stabilisers and flame retardants with less harmful substances.
Whatever the findings eventually show, there is little that can be done now to deal with the vast quantities of plastic already in our oceans. It will be there for decades to come.”

You can read more about the problems of micro plastic pollution here.

More Science

And if you want more data on the problem here are just a few of the hundreds of studies being done. Thanks to Fabiano of for keeping us well informed.

Jan Zalasiewicz, Colin N. Waters, Juliana Ivar do Sul, Patricia L. Corcoran, Anthony D. Barnosky, Alejandro Cearreta, Matt Edgeworth, Agnieszka Gałuszka, Catherine Jeandel, Reinhold Leinfelder, J.R. McNeill, Will Steffen, Colin Summerhayes, Michael Wagreich, Mark Williams, Alexander P. Wolfe, Yasmin Yonan, The geological cycle of plastics and their use as a stratigraphic indicator of the Anthropocene, Anthropocene, Available online 18 January 2016, ISSN 2213-3054,
Abstract: The rise of plastics since the mid-20th century, both as a material element of modern life and as a growing environmental pollutant, has been widely described. Their distribution in both the terrestrial and marine realms suggests that they are a key geological indicator of the Anthropocene, as a distinctive stratal component. Most immediately evident in terrestrial deposits, they are clearly becoming widespread in marine sedimentary deposits in both shallow- and deep-water settings. They are abundant and widespread as macroscopic fragments and virtually ubiquitous as microplastic particles; these are dispersed by both physical and biological processes, not least via the food chain and the ‘faecal express’ route from surface to sea floor. Plastics are already widely dispersed in sedimentary deposits, and their amount seems likely to grow several-fold over the next few decades. They will continue to be input into the sedimentary cycle over coming millennia as temporary stores – landfill sites – are eroded. Plastics already enable fine time resolution within Anthropocene deposits via the development of their different types and via the artefacts (‘technofossils’) they are moulded into, and many of these may have long-term preservation potential when buried in strata.
Keywords: Anthropocene; Plastics; Stratigraphy

Carme Alomar, Fernando Estarellas, Salud Deudero, Microplastics in the Mediterranean sea: Deposition in coastal shallow sediments, spatial variation and preferential grain size, Marine Environmental Research, Available online 18 January 2016, ISSN 0141-1136,
Abstract: Marine litter loads in sea compartments are an emergent issue due to their ecological and biological consequences. This study addresses microplastic quantification and morphological description to test spatial differences along an anthropogenic gradient of coastal shallow sediments and further on to evaluate the preferential deposition of microplastics in a given sediment grain fraction. Sediments from Marine Protected Areas (MPAs) contained the highest concentrations of microplastics (MPs): up to 0.90±0.10 MPs/g suggesting the transfer of microplastics from source areas to endpoint areas. In addition, a high proportion of microplastic filaments were found close to populated areas whereas fragment type microplastics were more common in MPAs. There was no clear trend between sediment grain size and microplastic deposition in sediments, although microplastics were always present in two grain size fractions: 2mm>x>1mm and 1mm>x 0.5mm.
Keywords: Marine litter; MPAs; Anthropogenic gradient; Sieve fractions; Contamination; Balearic islands

Teresa Rocha-Santos, Armando C. Duarte, A critical overview of the analytical approaches to the occurrence, the fate and the behavior of microplastics in the environment, TrAC Trends in Analytical Chemistry, Available online 11 December 2014, ISSN 0165-9936,
Abstract: Plastics can be found in food packaging, shopping bags, and household items, such as toothbrushes and pens, and facial cleansers. Due to the high disposability and low recovery of discharged materials, plastics materials have become debris accumulating in the environment. Microplastics have a dimension <5 mm and possess physico-chemical properties (e.g., size, density, color and chemical composition) that are key contributors to their bioavailability to organisms. This review addresses the analytical approaches to characterization and quantification of microplastics in the environment and discusses recent studies on their occurrence, fate, and behavior. This critical overview includes a general assessment of sampling and sample handling, and compares methods for morphological and physical classification, and methodologies for chemical characterization and quantification of the microplastics. Finally, this review addresses the advantages and the disadvantages of these techniques, and comments on future applications and potential research interest within this field.
Keywords: Debris; Detection; Environment; Marine environment; Microplastic; Plastic; Sampling; Seawater; Sediment; Water

Note to users: Accepted manuscripts are Articles in Press that have been peer reviewed and accepted for publication by the Editorial Board of this publication. They have not yet been copy edited and/or formatted in the publication house style, and may not yet have the full ScienceDirect functionality, e.g., supplementary files may still need to be added, links to references may not resolve yet etc. The text could still change before final publication.

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Reisser J, Proietti M, Shaw J and Pattiaratchi C (2014) Ingestion of plastics at sea: does debris size really matter? Front. Mar. Sci. 1:70. doi: 10.3389/fmars.2014.00070

Keywords: microplastics, marine debris, plastic ingestion, zooplankton grazing, copepods

Reisser, J., Slat, B., Noble, K., du Plessis, K., Epp, M., Proietti, M., de Sonneville, J., Becker, T., and Pattiaratchi, C.: The vertical distribution of buoyant plastics at sea, Biogeosciences Discuss., 11, 16207-16226, doi:10.5194/bgd-11-16207-2014, 2014.

Abstract. Millimeter-sized plastics are numerically abundant and widespread across the world’s ocean surface. These buoyant macroscopic particles can be mixed within the upper water column due to turbulent transport. Models indicate that the largest decrease in their concentration occurs within the first few meters of water, where subsurface observations are very scarce. By using a new type of multi-level trawl at 12 sites within the North Atlantic accumulation zone, we measured concentrations and physical properties of plastics from the air–seawater interface to a depth of 5 m, at 0.5 m intervals. Our results show that plastic concentrations drop exponentially with water depth, but decay rates decrease with increasing Beaufort scale. Furthermore, smaller pieces presented lower rise velocities and were more susceptible to vertical transport. This resulted in higher depth decays of plastic mass concentration (mg m−3) than numerical concentration (pieces m−3). Further multi-level sampling of plastics will improve our ability to predict at-sea plastic load, size distribution, drifting pattern, and impact on marine species and habitats.

Review Status
This discussion paper is under review for the journal Biogeosciences (BG).




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One thought on “Microplastic in the sea. Studies.

  1. There are several different types of degradable plastic.

    Oxo-biodegradable plastic (see is not “just plastic dust glued together with glue”

    Recycled plastics are OK, but they are not degradable and will still lie around in the environment for decades.

    Ordinary plastic and recycled plastic can now be made oxo-biodegradable.

    This is done by including d2w additive (see which makes it degrade, then biodegrade, on land or at sea, in the light or the dark, in heat or cold, in whatever timescale is required, leaving NO fragments NO methane and NO harmful residues. Oxo-bio passes the tests in American Standard 6954, and is made from a by-product of oil refining which used to be wasted, so nobody is importing extra oil to make it.

    There is little or no additional cost.

    Plastics made from crops, are up to 400% more expensive, they are not strong enough for use in high-speed machinery, and they emit methane (a powerful greenhouse gas) in landfill. Also, it is wrong to use land, water and fertilisers to grow crops for bioplastics and biofuels, which drives up the cost of food for the poorest people. See The Guardian 26th April 2008

    The same applies to growing cotton or jute to make durable bags. These rapidly become unhygienic if a tomato is squashed or milk is spilled, and become a durable form of litter, but they can be made from washable oxo-bio plastic to last up to 5 years.

    Oxo-bio plastics degrade in the upper layers of a landfill, so they will take up less space, but they are completely inert deeper in the landfill in the absence of oxygen. They do not emit methane at any stage.

    Paper bags use 300% more energy to produce, they are bulky and heavy and are not strong enough. They will also emit methane in landfill

    Compostability of plastics is an irrelevance because compostable plastics are far too expensive for everyday use, and there are very few industrial composting facilities. Also, as it is difficult and expensive to separate compostable plastics from other plastics, many industrial composters do not want plastic of any kind in their feedstock.

    Compostable plastics will damage the recycling process if they get into in a normal plastic recycling waste stream

    Home composting of plastic packaging is dangerous and should not be encouraged, as it is often contaminated with meat, fish, or poultry residues, and temperatures do not rise high enough to kill the pathogens.

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