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.

Composition, spatial distribution and sources of macro-marine litter on the Gulf of Alicante seafloor (Spanish Mediterranean)

The composition, spatial distribution and source of marine litter in the Spanish Southeast Mediterranean were assessed. The data proceed from a marine litter retention programme implemented by commercial trawlers and were analysed by GIS. By weight, 75.9% was plastic, metal and glass. Glass and plastics were mainly found close to the coast. A high concentration of metal was observed in some isolated zones of both open and coastal waters. Fishing activity was the source of 29.16% of the macro-marine litter, almost 68.1% of the plastics, and 25.1% of the metal. The source of the other 60.84% could not be directly identified, revealing the high degree of uncertainty regarding its specific origin. Indirectly however, a qualitative analysis of marine traffic shows that the likely sources were merchant ships mainly in open waters and recreational and fishing vessels in coastal waters.