title: Understanding the Fragmentation Pattern of Marine Plastic Debris.
abstract: The global estimation of microplastic afloat in the ocean is only approximately 1% of annual global plastic inputs. This reflects fundamental knowledge gaps in the transformation, fragmentation, and fates of microplastics in the ocean. In order to better understand microplastic fragmentation we proceeded to a thorough physicochemical characterization of samples collected from the North Artlantic subtropical gyre during the sea campaign Expedition seventh Continent in May 2014. The results were confronted with a mathematical approach. The introduction of mass distribution in opposition to the size distribution commonly proposed in this area clarify the fragmentation pattern. The mathematical analysis of the mass distribution points out a lack of debris with mass lighter than 1 mg. Characterization by means of microscopy, microtomography, and infrared microscopy gives a better understanding of the behavior of microplastic at sea. Flat pieces of debris (2 to 5 mm in length) typically have one face that is more photodegraded (due to exposure to the sun) and the other with more biofilm, suggesting that they float in a preferred orientation. Smaller debris, with a cubic shape (below 2 mm), seems to roll at sea. All faces are evenly photodegraded and they are less colonized. The breakpoint in the mathematical model and the experimental observation around 2 mm leads to the conclusion that there is a discontinuity in the rate of fragmentation: we hypothesized that the smaller microplastics, the cubic ones mostly, are fragmented much faster than the parallelepipeds.
authors.affiliation: Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique (IMRCP), UMR CNRS 5623, Université Paul Sabatier-UPS , Bâtiment 2R1, 3ème étage, 118, route de Narbonne, 31062 Toulouse Cedex 09, France.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Ter Halle
authors.affiliation: Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique (IMRCP), UMR CNRS 5623, Université Paul Sabatier-UPS , Bâtiment 2R1, 3ème étage, 118, route de Narbonne, 31062 Toulouse Cedex 09, France.
authors.forename: Lucie
authors.initials: L
authors.lastname: Ladirat
authors.affiliation: Institut de Mathématique de Toulouse (IMT), UMR CNRS 5219, Université Paul Sabatier , 133, route de Narbonne, 31062 Toulouse Cedex 4, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Gendre
authors.affiliation: Centre de Microscopie Electronique Appliquée à la Biologie,Faculté de Médecine Toulouse Rangueil, Université de Toulouse , 133, route de Narbonne, 31062 Toulouse Cedex 4, France.
authors.forename: Dominique
authors.initials: D
authors.lastname: Goudouneche
authors.affiliation: Ocean Science & Logistic , 14 rue Cresson, 97310 Kourou, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Pusineri
authors.affiliation: Université de Toulouse, UPS, ICT , 118 route de Narbonne, F-31062 Toulouse Cedex 9, France.
authors.forename: Corinne
authors.initials: C
authors.lastname: Routaboul
authors.affiliation: Centre Interuniversitaire de Recherche et d'Ingénierie des MATériaux (CIRIMAT), UMR CNRS 5085, Université Paul Sabatier-UPS , 118 route de Narbonne, 31062 Toulouse Cedex 09, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Tenailleau
authors.affiliation: Centre Interuniversitaire de Recherche et d'Ingénierie des MATériaux (CIRIMAT), UMR CNRS 5085, Université Paul Sabatier-UPS , 118 route de Narbonne, 31062 Toulouse Cedex 09, France.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Duployer
authors.affiliation: Laboratoire des Interactions Moléculaires et Réactivité Chimique et Photochimique (IMRCP), UMR CNRS 5623, Université Paul Sabatier-UPS , Bâtiment 2R1, 3ème étage, 118, route de Narbonne, 31062 Toulouse Cedex 09, France.
authors.forename: Emile
authors.initials: E
authors.lastname: Perez
mesh_terms: D004784:Environmental Monitoring; D006794:Household Articles; D008962:Models, Theoretical; D010969:Plastics; D014866:Waste Products
chemical_list: D010969:Plastics; D014866:Waste Products