Beached microplastics in the Northwestern Mediterranean Sea

Mel Constant (1) , Philippe Kerhervé (1) , Morgan Mino-Vercellio-Verollet (1) , Marc Dumontier (2) , Anna Sànchez Vidal (2) , Miquel Canals (2) , Serge Heussner (1)

1 CEFREM - Centre de Formation et de Recherche sur les Environnements Méditérranéens
2 UB - Universitat de Barcelona

Microplastics are small (<5 mm) fragments of plastic debris that are ubiquitous in coastal areas and in open ocean. We have investigated the occurrence and composition of microplastics in beach sediments from themicro-tidal Northwestern Mediterranean Sea. Samples were collected on two beaches (northern and southern site) of the western Gulf of Lion showing markedly different characteristics. Sampling was performed along depositional lower, mid and upper beaches and repeated after 1 month. Concentrations of microplastics in the northern and southern site were highly variable, ranging from 33 to 798 and from 12 to 187 microplastics per kg of dry sediment, respectively. Highest concentrations were found at three specific locations: nearby a local river mouth, within an accretionary area and in a depositional upper beach. The spatial and temporal distribution of beached microplastics seems to be directly dependent on external forcing such as wind, swell, precipitation, outflow and river mouth proximity.

Mots clés: micoplastics; Mediterranean sea; Gulf of Lion; Micro-tidal system; Beach

Domaines: Milieux et Changements globaux

Mel Constant, Philippe Kerhervé, Morgan Mino-Vercellio-Verollet, Marc Dumontier, Anna Sànchez Vidal, et al.. Beached microplastics in the Northwestern Mediterranean Sea. Marine Pollution Bulletin, 2019, ⟨10.1016/j.marpolbul.2019.03.032⟩. ⟨hal-02328747⟩