Exceptionally high abundances of microplastics in the oligotrophic Israeli Mediterranean coastal waters Noam van der Hal a , Asaf Ariel b , Dror L. Angel a, ⁎ a The Department of Maritime Civilizations, Charney School for Marine Science, University of Haifa, Israel b EcoOcean, Marine Research & Education, Kibbutz Sdot Yam, Israel abstract article info Article history: Received 3 September 2016 Received in revised form 15 December 2016 Accepted 17 December 2016 Available online xxxx Seasonal sea surface microplastic distribution was recorded at 17 sites along the Israeli Mediterranean coast. Microplastics (0.3–5 mm) were found in all samples, with a mean abundance of 7.68 ± 2.38 particles/m 3 or 1,518,340 particles/km 2 . Some areas had higher abundances of microplastics than others, although differences were neither consistent nor statistically significant. In some cases microplastic particles were found floating in large patches. One of these patches contained an extraordinary number of plastic particles; 324 particles/m 3 or 64,812,600 particles/km 2 . Microplastic abundances in Israeli coastal waters are disturbingly high; mean values were 1–2 orders of magnitude higher than abundances reported in other parts of the world. Light-colored (white or transparent) fragments were by far more abundant than all other microplastic colors and types. The results of this study underline the need for action to reduce the flux of plastics to the marine environment. © 2016 Elsevier Ltd. All rights reserved. 1. Introduction Marine debris impacts the health and integrity of marine ecosystems and may exert considerable stress on marine biota (Derraik, 2002; Thompson et al., 2004; Deudero and Alomar, 2015). Characterization of marine debris in various parts of the world has shown that the bulk of the solid material originates from terrestrial sources and consists of a wide array of plastic compounds (Andrady, 2011; Jambeck et al., 2015). Although many of the plastic particles that enter the sea are large (N 5 mm), physical, biological and chemical processes which occur both in the water column and on the seafloor eventually reduce these to smaller particles (b 5 mm), collectively classified as “microplastics” (Arthur et al., 2009). These particles are ubiquitous and the most abundant of all marine plastic debris sizes (Eriksen et al., 2014; Cózar et al., 2014). Microplastics produced by the breakdown of larger particles are known as ‘secondary’ microplastics, in contrast to ‘primary’ microplastics (pellets, cosmetic beads, etc.), which are manufactured particles that are smaller than 5 mm (Brown et al., 2007; Rios et al., 2007; Fendall and Sewell, 2009). Until recently, microplastic debris was not recognized as an impor- tant form of marine pollution and its abundance and distribution were generally not documented (Carpenter et al., 1972; Thompson et al., 2004; Allsopp et al., 2006). Studies carried out in the past two decades indicate that microplastic particles have a cosmopolitan distribution (Brown et al., 2008; Thompson et al., 2009). As the plastic debris erodes, the availability of microplastics to organisms that occupy the water col- umn as well as the seafloor increases (Moore et al., 2005; Cole et al., 2013; Woodall et al., 2014). Numerous factors, such as the shape of the coast line, eddies and gyres, wind and wave action, biofouling, salinity and temperature, may influence the distribution of microplastics (Barnes et al., 2009; Andrady, 2011; Doyle et al., 2011). Moore et al. (2001a, b, 2002) found an increase in microplastic abundances inside the North Pacific Gyre and towards the coastline and river outflows, especially after heavy rains. Jung-Hoon et al. (2015) also found greater abundances of microplastics after the rainy season. Collignon et al. (2012) reported an increase in microplastic abundances in calm seas as compared to the situation following a period of strong winds, probably related to the vertical mixing of plastics to depths below the sea surface (Kukulka et al., 2012). Lebreton et al. (2012) and Cózar et al. (2015) sug- gest that the Mediterranean Sea is enriched in microplastics because it is a largely enclosed basin with water flowing into it from both the Atlan- tic Ocean and from numerous large rivers. This may lead to a high ratio of microplastic particles to biomass (Collignon et al., 2014); especially in the eastern part of the Mediterranean where waters are highly- oligotrophic (Moutin and Raimbault, 2002). Cózar et al. (2015) assembled a large-scale review of the Mediterra- nean Sea and found that microplastic abundances were similar to those found in the Pacific Ocean gyres, with a mean abundance of 0.83 microplastic particles/m 3 (in communication; data from Cózar et al., 2015). In the western Mediterranean Sea, microplastic particles were found in 90% of the samples examined, with a mean abundance of Marine Pollution Bulletin xxx (2016) xxx–xxx ⁎ Corresponding author at: Leon Recanati Institute for Maritime Studies, University of Haifa, 199 Abba Khoushy Blvd, Mount Carmel, Haifa 3498838, Israel. E-mail address: adror@research.haifa.ac.il (D.L. Angel). MPB-08271; No of Pages 5 http://dx.doi.org/10.1016/j.marpolbul.2016.12.052 0025-326X/© 2016 Elsevier Ltd. All rights reserved. Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Please cite this article as: van der Hal, N., et al., Exceptionally high abundances of microplastics in the oligotrophic Israeli Mediterranean coastal waters, Marine Pollution Bulletin (2016), http://dx.doi.org/10.1016/j.marpolbul.2016.12.052