Déchet en mer | EPFL Graph Search

vignette|Macrodéchets de surface, apportés par les courants marins sur la côte hawaïenne. Bien qu'il soit illégal de jeter en mer tout type de déchets ou objet en plastique aux États-Unis, le plastique constituerait 80 % des déchets trouvés en mer en 2009. vignette|Les albatros ne peuvent digérer une partie de leurs aliments (vertèbres et grosses arêtes de poissons, « becs » de calmars), mais on retrouve de plus en plus dans leur bol alimentaire des déchets plastiques non dégradables (ici brosse à dent et plusieurs monofilaments de nylon provenant de fil de pêche ou de filets de pêche perdus ou abandonnés en mer). (albatros à pieds noirs ou un Laysan). L'ingestion de déchets plastique flottant est une cause de plus en plus fréquente de mortalité d'albatros. La notion de « déchets en mer » ou « déchets marins » ou « débris marins » (marine litter en anglais) regroupe :

des déchets d'origine naturelle (exemple : bois flotté) qui ont rôle dans le cycle du carbone et d’autres nutriments

Identification and characterization of microplastics in the Lake Geneva environment

Charlotte Thérèse Bondaz

This project is set in a context of raising awareness concerning the accumulation of plastics in oceans. As opposed to the marine environment, there is a real gap of knowledge on microplastics pollution in freshwaters. In this project, the Lake Geneva environment is investigated, concentrating on the Venoge River, the lake water surface, and the “déversoir du Capelard” – a storm overflow in Lausanne. In order to get a rapid and complete method to characterize microplastics in the Lake Geneva environment, some polymer analysis tools are suggested and tested. The goals of the study are to identify the plastic debris and to characterize the oxidation state of five different polyethylene samples. The Fourier Transform Spectroscopy appears to be an acceptable solution despite some limits. DSC would require some more researches and microscopy needs a long analysis time for little information.

2015

An evaluation of surface micro and meso plastic pollution in pelagic ecosystems of western Mediterranean Sea

Luiz Felippe De Alencastro, Florian Faure, Pascal Hagmann

In the 90’s, the discovery of high concentrations of plastic debris in the oceans generated interest and concern of general public as well as scientific community. Since, the accumulation of plastic debris in the North Pacific and North Atlantic gyres has been widely reported. Surprisingly, only few quantitative studies exist concerning the Mediterranean Sea. The purpose of this study was to examine the distribution, abundance and characteristics of surface micro (size 0.33 – 5.0 mm) and meso (size 5.0 – 50 mm) plastic debris, as compared to the abundance of organic material, in the western Mediterranean Sea. 41 samples have been collected during 2 cruises in September 2011 and August 2012 in regions distributed between positions 38-44°N and 001-010°E (Gulf of Lion, Eastern Spanish coast, Balearic Islands, Sardinia, Corsica). Sample collection was performed using a surface net tow of 330 μm mesh size. Samples were sieved to separate particles smaller than 5 mm from larger ones; plastic pieces were extracted from the plankton and organic matter, and sorted in 6 categories: fragments, pellets, thin films, foams, lines and others (tar, etc.). Each were counted and weighted, as was the organic matter once dried. The concentrations of micro-plastic debris were measured in term of particles number and particles mass per surface unit. The average values of 130’000 parts/km2 and 58’000 mg/km2, respectively were measured, with highest concentrations reaching values superior to 420’000 parts/km2 and 140’000 mg/km2. A qualitative analysis mainly revealed the presence of fragments (77% in mass), but also thin films (13%), foams (7%), pellets (2%) and lines (2%). The average ratio of micro-plastic mass to dry organic material mass has been measured at 1.04. A fraction of the samples was collected in low wind conditions (u10 < 4 m/s), while the other part was collected under medium wind conditions (4 ≤ u10 ≤ 11 m/s). As the vertical distribution of micro-plastic is known to be highly sensitive to wind stress, the values have been corrected and re-interpreted using the methodology proposed by Kukulka & al. 2012. The resulting corrected values suggest that the employed sampling process underestimated the surface micro-plastic concentration by an average factor of 1.55. The average concentrations of meso-plastic debris reached the number of 5’500 parts/km2 and the mass of 120’000 mg/km2, mostly fragments (57%) and thin films (34%). The results revealed that (1) plastic marine debris are widely distributed in western Mediterranean sea, (2) plastic debris concentrations in the Mediterranean Sea are of the same order of magnitude than those measured in the North Atlantic or North Pacific subtropical gyres and (3) plastic debris concentrations are about the same order of magnitude than dry organic material, arguing in favor of the hypothesis of potential misinterpretation and ingestion of these particles by plankton feeders in the sea. Kukulka T, Proskurowski G, Moret-Ferguson S, Meyer D, Lavender Law K, 2012. Geophysical Research Letters, vol 39.

2013

An evaluation of surface micro- and mesoplastic pollution in pelagic ecosystems of the Western Mediterranean Sea

Luiz Felippe De Alencastro, Florian Faure, Pascal Hagmann

This study examines the distribution, abundance and characteristics of surface micro- and mesoplastic debris in the Western Mediterranean Sea. 41 samples were collected in 2011 (summer) and 2012 (summer). Results, firstly, revealed that micro- (

Springer Heidelberg2015

An evaluation of surface micro and meso plastic pollution in pelagic ecosystems of western Mediterranean Sea

Luiz Felippe De Alencastro, Florian Faure, Pascal Hagmann

2013