Microplastics in the Ocean

Abstract

Since their ubiquity in the ocean and marine organisms was first revealed, global concern about microplastics has grown considerably. The North Pacific Ocean and the adjacent marginal seas have high levels of microplastic contamination compared with the global average. This special issue on microplastics was organized by the North Pacific Marine Science Organization to share information on microplastic pollution in the North Pacific region. The special issue highlights high levels of contamination in the North Pacific both on shorelines and at the sea surface. Particularly high levels of contamination were reported on the western and southern coasts of Korea. Sources, including sewage discharge, aquaculture, and shipyards, were implicated. With the direction and energy of surface winds and currents have an important influence on shoreline patterns of distribution. The special issue also demonstrates potential for ingestion of microplastic by small planktonic organisms at the base of the food chain. A wide range of chemicals are associated with plastic debris and concerns are expressed about the potential for these chemicals to transfer to biota upon ingestion. As an introduction to the topic, this paper provides a brief background on microplastic contamination, highlights some key research gaps, and summarizes findings from the articles published in this issue.

Microplastics in seafood: Benchmark protocol for their extraction and characterization

“…From the surface to the ocean floor, studies have described between 7000 tons and 250,000 tons of plastics floating at the surface of seawater (Cozar et al, 2014;Eriksen et al, 2014), in the water column (Lattin et al, 2004) and in seabed sediments (Fischer et al, 2015;Fries et al, 2013;Van Cauwenberghe et al, 2013). Plastics in oceans are encountered in macro-(>25 mm), meso-(5e25 mm) and microplastic forms (<5 mm) (Arthur et al, 2009;Shim and Thompson, 2015;Thompson, 2004). Primary microplastics are referred to as microparticles produced as such, i.e.…”

Microplastic prevalence in two fish species in two U.S. reservoirs

“…Microplastics are composed of synthetic organic polymers that can contain possibly hazardous chemical additives and can also adsorb harmful chemicals from the environment and serve as vectors for persistent organic pollutants (Rochman et al 2013). As plastic degrades, particle size decreases, allowing ingestion by a larger range of organisms, and the larger surface area to volume ratio can increase the potential for leaching of harmful chemicals in plastics including cadmium, lead, and phthalates (Shim and Thompson 2015). Chemicals leached from ingested microplastics can be absorbed directly into the consumer (Rochman et al 2013;Ding et al 2018) leading to physiological impacts on reproductive success, behavior, and growth (Rochman et al 2014).…”

Determining global distribution of microplastics by combining citizen science and in‐depth case studies

“…For example, whereas the majority of studies reported the number of particles per weight of sediment sample (e.g., particles/kg sand [dry weight]; 9 studies), some studies reported the number of particles per unit area (e.g., particles/m 2 ; 7 studies) ( Table 1) and others as the weight of microplastics per weight of sediment (e.g., mg plastics/kg sand) or area (mg plastic/m 2 ) (Table 1). These variations in sampling, extracting and reporting of outcomes makes it difficult, if not impossible, to directly compare loads of microplastics across studies (Hidalgo-Ruz et al 2012;Shim and Thomposon 2015;Van Cauwenberghe et al 2015). These variations in sampling, extracting and reporting of outcomes makes it difficult, if not impossible, to directly compare loads of microplastics across studies (Hidalgo-Ruz et al 2012;Shim and Thomposon 2015;Van Cauwenberghe et al 2015).…”

“…At this point, however, there are significant differences in how different scientists across the world sample, extract, and quantify microplastics (Hidalgo-Ruz et al 2012;Shim and Thomposon 2015;Van Cauwenberghe et al 2015). For example, we recently showed that there is a significant amount of variation in both sampling and extraction protocols from beach sand (Besley et al 2017).…”

“…Moreover, the description of the physicochemical characteristics of microplastics also showed significant variation across studies, with the shape of the sample (10 studies), the type of polymer (6 studies), and the size ranges of the particles (6 studies) most commonly reported (Table 1). These variations in sampling, extracting and reporting of outcomes makes it difficult, if not impossible, to directly compare loads of microplastics across studies (Hidalgo-Ruz et al 2012;Shim and Thomposon 2015;Van Cauwenberghe et al 2015).…”