Spatial and temporal trends of marine litter in the Spanish Mediterranean seafloor

Composition, spatial distribution and temporal evolution of marine litter on the Spanish Mediterranean seafloor were assessed. The data derive from Spanish MEDITS surveys over 11 years and were analysed by GIS. A total amount of 2197.8 kg of litter was collected. Marine litter (by weight) was composed of plastics (29.3%), clinker (28.4%), wood (10.2%), metal (9.7%) and glass (6.2%). Its density varied among Areas (Alboran Sea > Valenciana > Alboran Island > Tramontana). For the last 11 years, the marine litter has remained stable or decreases in some case. The information provided by this study is a useful baseline to study such debris on the Spanish seafloor. The MEDITS survey has proven to be an appropriate monitoring tool, also of use to assess future control measures.