Plastic Accumulation in the Mediterranean Sea

Abstract

Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region.

Plastic Debris Occurrence, Convergence Areas and Fin Whales Feeding Ground in the Mediterranean Marine Protected Area Pelagos Sanctuary: A Modeling Approach

“…Polyethylene was found to be the most common plastic polymer among the plastic debris in the Mediterranean Sea and other oceans worldwide (Hidalgo-Ruz et al, 2012;Cózar et al, 2014). The data on floating plastic abundance confirm the high concentration found by other authors in the Mediterranean Sea (Cózar et al, 2015), identified as the sixth accumulation area for marine litter together with the main five oceanic gyres, as also predicted by global models (Eriksen et al, 2014). The assessment of the potential exposure of fin whale to plastic was obtained comparing empirical data with a model of the fin whale feeding habitat and a model estimating the concentration of floating debris for the SPAMI Pelagos Sanctuary.…”

“…As for the Mediterranean sea, the average concentration found is comparable to the high values found in subtropical gyres (Cózar et al, 2015;Suaria et al, 2016). This high concentration is in part explainable considering the retention of floating debris facilitated by a limited surface outflow toward the Atlantic ocean (Lebreton et al, 2012).…”

“…In the Mediterranean Sea, marine litter has recently been confirmed as a critical issue (Eriksen et al, 2014;Cózar et al, 2015;UNEP/MAP, 2015;Suaria et al, 2016). The highest fraction (∼80%) of marine litter comprises plastic, particularly small sized plastic.…”

“…This marine area, located in the north-western Mediterranean Sea, is characterized by high offshore productive frontal features that attract a variety of large marine vertebrates including eight cetacean species (Coll et al, 2012). This exceptional biodiversity coexists with high human pressure (Fossi et al, 2013;Pinzone et al, 2015), including plastic pollution (Collignon et al, 2012;Fossi et al, 2012;Cózar et al, 2015).…”

Microplastics in the Ocean

“…The North Pacific Ocean and its marginal seas have the highest microplastic contamination levels in the world (Eriksen et al 2014;Song et al 2014;Cózar et al 2015). Therefore, it is important to collect and share information on microplastic pollution in the North Pacific region among global scientific and policy audiences.…”