Nearshore spatio-temporal sea surface trawls of plastic debris in the Balearic Islands.

Nearshore sea-surface manta trawls were carried out monthly at seven sites along the coastline of Mallorca in the Balearic Islands in the Western Mediterranean Sea. Plastic marine debris was present in all trawls (n = 63) with an overall average abundance of 858,029 ± 4,082,964 items/km2 (mean ± standard deviation) and weight of 4,520 ± 22,806 g(DW)/km2 and the micro-plastic fraction (74%) dominating the size class. Polyethylene (LDPE and HDPE) was the most common polymer (70%) with high spatial heterogeneity, especially along the north-western coast. August showed almost two-fold as much plastic as the other months, and the number of items decreased significantly with distance from the coastline. A positive correlation was found with the fractal dimension of the coastline indicating higher coastal plastic debris retention in areas with a higher fractal dimension and backtracking simulations indicated that marine litter was mainly locally sourced. Overall results indicate a significant small scale variability of nearshore coastal marine plastic in the Balearic Islands.

Compa M ，Alomar C ，Mourre B ，March D ，Tintoré J ，Deudero S ... -  《-》

Spatio-temporal monitoring of coastal floating marine debris in the Balearic Islands from sea-cleaning boats.

Mismanaged waste is accumulating at an alarming rate in the marine environment. Its presence has caused local authorities in the Balearic Islands to develop a coastal sea-cleaning boat service covering the region, identifying the floating marine debris, and removing it from the coastal areas. This study considered daily monitoring from May to October spanning from 2005 to 2015. Plastic marine debris composed over 54% of all floating marine debris removed daily across the Balearic Islands. The spatio-temporal patterns indicate a heterogeneous distribution of plastic in the coastal areas, with higher concentrations in the north-western and south-eastern regions of the islands and debris peaking during the month of August. Furthermore, floating marine debris was more easily collected during calm seas as well as using an integrated monitoring approach to facilitate its removal. Overall, sea-cleaning boats are highly effective in removing coastal floating marine debris.

Compa M ，March D ，Deudero S 《-》

Now, you see me: High concentrations of floating plastic debris in the coastal waters of the Balearic Islands (Spain).

Coastal ecosystems are under significant human pressure, partly due to the proximity of pollution sources. In this study, a total of 20 samples were taken in summer around the coastal waters of the Balearic Islands (Spain) using a manta trawl net to examine the concentrations of floating plastic debris through the NIXE III project campaign. Although plastic concentrations showed high variability along the coast, the higher particle concentration (max: 4,576,115 items ⋅ km-2) and weight (max: 8,102.94 g(DW) ⋅ km-2) values were located at the north of the Balearic Promontory. The particle size analysis showed the high prevalence of microplastics (< 5 mm) in these waters, where particles of approximately 0.7 mm and 1 mm2 were the most frequent in the range analyzed. The high plastic concentration values in the N-NW coast of Ibiza and Mallorca in sparsely populated locations suggest that the plastic particle distribution was mostly conditioned by the hydrodynamic surface conditions.

Ruiz-Orejón LF ，Sardá R ，Ramis-Pujol J 《-》

Marine plastics in Mediterranean islands: Evaluating the distribution and composition of plastic pollution in the surface waters along four islands of the Western Sea Basin.

To study the spatial distribution of sea surface plastics in marine protected and non-protected areas, 65 sea surface trawls were carried out using a Hydro-bios manta net coupled with a 335-μm mesh. A total of 19 sampling sites along the coastal waters of Mallorca, the "Parque Nacional Marítimo-Terrestre del Archipiélago de Cabrera" and Menorca in the Balearic Islands as well as along coastal waters of The Natural Park of Columbretes Islands (NW Mediterranean Sea) were sampled. A total of 10,637 plastic items were identified and a subset of these items was categorized by shape, color, size and polymer composition. Plastic particles were found at each sampling site and in all samples. No microscale nor mesoscale variability in floating marine plastics abundance (particles/m2) was encountered throughout the study area where similar values were found in protected areas with no local land-based contamination sources, such as Columbretes [0.04 (±0.03) particles/m2], and in high anthropized areas, such as the island of Mallorca [0.04 (±0.07) particles/m2]. However, differences were found in characteristics of plastic items (shape, polymer, and size range), with the protected area of Columbretes characterized by the presence of the highest density of very small plastic items composed mainly of fragments (93%). Quantified plastics from the marine environment were composed mainly of polyethylene (PE, 63.3%), polypropylene (PP; 24.9%), polycarbonate (PC; 4.6%) and polystyrene (PS, 3.3%). The polymer composition showed a homogenous composition between islands and differences were detected only amongst Columbretes and the other islands. Results from this study provide further evidence of the ubiquity of plastics in the marine environment and highlight that remote and protected areas, such as Columbretes, are not exempt from plastic pollution, but receptor areas for small and aged floating plastics composed mainly by fragments, which might have potentially harmful effects on protected ecosystems.

Fagiano V ，Compa M ，Alomar C ，García-Marcos K ，Deudero S ... -  《-》

Floating plastic debris in the Central and Western Mediterranean Sea.

In two sea voyages throughout the Mediterranean (2011 and 2013) that repeated the historical travels of Archduke Ludwig Salvator of Austria (1847-1915), 71 samples of floating plastic debris were obtained with a Manta trawl. Floating plastic was observed in all the sampled sites, with an average weight concentration of 579.3 g dw km(-2) (maximum value of 9298.2 g dw km(-2)) and an average particle concentration of 147,500 items km(-2) (the maximum concentration was 1,164,403 items km(-2)). The plastic size distribution showed microplastics (<5 mm) in all the samples. The most abundant particles had a surface area of approximately 1 mm(2) (the mesh size was 333 μm). The general estimate obtained was a total value of 1455 tons dw of floating plastic in the entire Mediterranean region, with various potential spatial accumulation areas.

Ruiz-Orejón LF ，Sardá R ，Ramis-Pujol J 《-》