plastic pollution in our oceans
general information about plastic
The origin of plastic
Plastic first appeared 60 years ago. What makes this material so unique?
Plastic is a very resistant material, made of carbon polymers whose composition varies between different types of plastic, giving them different properties.
There are 3 families of plastics:
Thermoplastics that are capable of being deformed and shaped into different shapes when they cool after being affected by heat. This property makes these types of plastic polymers recyclable. Among the thermoplastics are the synthetic fibers used, for example, in synthetic clothing.
Thermosetting plastics which have a geometrically fixed structure. They are therefore rigid, brittle, insoluble and infusible, which makes these types of plastics non-recyclable.
Elastomers are able to withstand large deformations before breaking. Elastomers include tire rubber and shoe soles.
Global plastic production
Since their appearance, plastic production has continued to increase. The latest data from 2018 (1) quantifies global plastic production at 360 million tonnes. Europe contributes 17% to this production with 62 million tonnes produced in 2018.
The country that contributes the most to this production is China , which alone produces 30% of the world's plastics.
The sectors that use the most plastic are the packaging and construction sectors .
Source: Plastics Europe Annual report of PlasticsEurope. “Plastics: the facts 2019”
Source: Plastics Europe Annual report of PlasticsEurope. “Plastics: the facts 2019”
The main polymers produced are polyolefins: polypropylene (PP) and polyethylene (PE).
Source: Plastics Europe Annual report of PlasticsEurope. “Plastics: the facts 2019”
ocean plastic pollution
The accumulation of plastic in the environment: from macroplastics to microplastics
The extreme resistance of plastic makes it a material that degrades very slowly, which logically leads to an accumulation of plastic debris in the environment, especially in the oceans. Once at sea, under the effect of winds, tides, and the sun, plastic macro-waste tends to fragment into plastic microparticles sometimes invisible to the naked eye, called microplastics:
Among all the debris currently identified, plastic debris is systematically the most abundant (2).
SEA Plastics' commitment against ocean plastic pollution
In order to better understand the behavior of plastic debris at sea, their location according to sea currents and their impact on living things, several scientific expeditions have carried out field studies. The water samples taken are generally taken in certain areas of interest, which are determined in advance by computer models predicting, among other things, the direction of the sea currents. A recent study showed a correlation between the quantity of plastics on the surface, and the presence of anticyclonic and low pressure currents (2). We base ourselves on these studies to carry out our samplings.
Depending on its density, plastic is usually considered to either float on the surface of the water or sink and settle to the bottom. Thus, very few studies focus on the mapping of plastic in the water column, that is to say the vertical distribution of plastic at sea . This is why one of our lines of research is directed towards the study of the vertical distribution of plastic.
Sources:
Thompson, RC, Olsen, Y., Mitchell, RP, Davis, A., Rowland, SJ, John, AWG, et al., 2004. Lost at sea: where is all the plastic? Science 304, 838. https://doi.org/10.1126/science.1094559 .
Barnes, DK, Galgani, F., Thompson, RC, Barlaz, M., 2009. Accumulation and fragmentation of plastic debris in global environments. Philos. Trans. R. Soc. London. Ser. B Biol. Science. 364, 1985–1998. https://doi.org/10.1098/rstb.2008.0205 .
Plastics Europe Annual report of Plastics Europe. “Plastics: the facts 2019”. Available from: http://www.plasticseurope.org (Internet, cited April 2020).