Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Baseline First evidence of microplastic pollution in the El Quetzalito sand beach of the Guatemalan Caribbean Carlos Mazariegos-Ortíz a,d,1 , María de los Ángeles Rosales b,d,1 , Leonel Carrillo-Ovalle a,d,1 , Renan Pereira Cardoso c,d,1 , Marcelo Costa Muniz c,d,1 , Roberto Meigikos dos Anjos c,d, ⁎ ,1 a Centro de Estudios del Mar y Acuicultura, Universidad de San Carlos de Guatemala, Ciudad Universitaria, zona 12, Guatemala b Fundación Mundo Azul, Ciudad Cayalá, zona 16, Guatemala c Laboratório de Radioecologia e Alterações Ambientais (LARA), Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-346 Niterói, RJ, Brazil d Red de investigación de los Estresores Marino Costeros de Latinoamerica y el Caribe –REMARCO, Brazil ARTICLE INFO Keywords: Plastic debris Polymer identification Microplastic characterization Marine protected area ABSTRACT In Guatemala, assessment of the impacts of microplastic pollution in marine and coastal protected areas has not yet been carried out. Therefore, the main goal of this paper was to evaluate the abundance, composition, physical forms, and the possible sources of plastic debris in the El Quetzalito Beach. The area was intended for biodiversity conservation but has been excessively contaminated by plastic materials from land-based activities. The results state that plastic debris negatively impact the Caribbean coast of Guatemala and are released by storm water and riverine transport from the Motagua River. With a high abundance of 279 items/m 2 (30 items/ kg d.w.), composed mainly of polystyrene foam beads (66.8%) and polypropylene fragments (25.8%), the mi- croplastic sources are the deterioration of large plastics. As these plastics are commonly used in industrial, commercial, fishing, and household activities, these findings reinforce the need to improve effective sustainable management actions of solid waste treatment and disposal in the Guatemalan cities. Persistent solid materials in all shapes and sizes have been discarded or abandoned in the marine environment, resulting in harmful effects on marine biodiversity as well as on human health (Jambeck et al., 2015; Pauly and Zeller, 2016; Geyer et al., 2017). Known as marine litter, they are from a wide range of land- and sea-based activities and are transported to the coastal environments by marine currents, winds, rivers, storm water, and sewage, or are deliberately discarded by locals and tourists on beaches and shores (IMO, 2018; Geyer et al., 2017).Approximately 80% of the marine plastic litter comes from cities with high population density and location near the coastline (Li et al., 2016). If the treatment and disposal of solid waste are improperly done, plastic debris can end up in the ocean. Indeed, Jambeck et al. (2015) estimated that, in 2010, 192 coastal countries generated 275 million MT of plastic material, with 4.8 to 12.7 million MT entering the ocean. Therefore, marine plastic litter has become so worrying that the sci- entific community predicts that there may be more plastic debris than fish, by weight, in the ocean by 2050 (Jambeck et al., 2015; Pauly and Zeller, 2016; Geyer et al., 2017). Once plastic litter enters coastal marine ecosystems, it undergoes biotic and abiotic processes (Wang et al., 2016). Although the polymers that make up their synthetic or semi-synthetic organic compounds have high durability, plastic materials can be deteriorated by the actions of ultraviolet rays, physical abrasion, and mechanic forces when exposed to solar radiation and marine winds and currents (Barnes et al., 2009). Beaches are therefore optimal environments for the breakdown of plastic materials (Corcoran et al., 2009). They combine chemical and mechanical weathering to promote the fragmentation of plastics, which can then become of microscopic size and mix with the beach sand. Microplastic (MP) refers to a plastic particle with a size range be- tween 1 μm and 5mm (Cole et al., 2011; Rocha-Santos and Duarte, 2015) and classified as primary or secondary according to its source. Primary MP is from intentionally manufactured products with micro- scopic size (such as microbeads and pellets), while secondary MP arises from the deterioration of larger plastic debris (Cole et al., 2011; Rocha- Santos and Duarte, 2017). Secondary MP usually has the shape of fi- lament, fragment, fiber, sheet, irregular film, broken edge, and granule https://doi.org/10.1016/j.marpolbul.2020.111220 Received 10 March 2020; Received in revised form 22 April 2020; Accepted 23 April 2020 ⁎ Corresponding author at: Laboratório de Radioecologia e Alterações Ambientais (LARA), Instituto de Física, Universidade Federal Fluminense, Av. Gal Milton Tavares de Souza, s/no, Gragoatá, 24210-346 Niterói, RJ, Brazil. E-mail address: meigikos@mail.if.uff.br (R.M. dos Anjos). 1 http://remarco.cl Marine Pollution Bulletin 156 (2020) 111220 Available online 01 May 2020 0025-326X/ © 2020 Elsevier Ltd. All rights reserved. T