Abstract
Plastic pollution is a global transboundary threat to the planet's marine resources. Tracking pollution is crucial to implement effective marine management strategies on coastal and island regions, where mismanaged plastics are most at risk of entering the ocean. However, the uncertainty of sources and pathways of marine litter poses a major challenge to the assessment of marine pollution. This chapter reviews the principal sectors and human activities contributing to plastic pollution, the mechanisms by which plastic enters the ocean, and some possible drivers of marine litter, including the growing role of coastal tourism on small developing islands. It also outlines future directions for meaningfully integrating research, material accounting, and prevention actions to mitigate the infiltration of plastic pollution in the marine environment, via proper monitoring, assessment, and reporting on plastic material flows from source to sink.
TopIntroduction
In just over a century, plastic has gone from being hailed as a “scientific wonder” to becoming an “environmental scourge” (Plummer, 2018). In fact, the social and economic benefits associated with plastic materials made them so popular that they have been documented in the most remote corners of the planet (Andrady & Neal, 2009; Thompson et al., 2009). Plastic pollution is defined as the totality of plastic accumulation in the environment, as well as the ecological impacts associated with its production, consumption, mismanagement, and emissions related to end-of-life practices (Nielsen et al., 2020). The scale of plastic pollution is striking, causing US$75 billion social and environmental costs every year (UNEP, 2014a). It has been estimated that over 8 million metric tons of plastics enter our oceans every year (Jambeck et al., 2015), and this flow is expected to nearly triple by 2040 (The Pew Charitable Trust & SYSTEMIQ, 2020), with tremendous consequences for the subsistence of marine life (Derraik, 2002).
A growing body of research has reported that plastic litter is one of the most serious threats to the underwater world, making the study of marine plastic pollution a key priority (Li et al., 2016). However, our knowledge of the magnitude and distribution of plastic pollution in the planet’s oceans is relatively new and there is still much uncertainty about the sources and pathways of marine pollution (Thompson et al., 2004; Cózar et al. 2014). This is due to the difficulties in assessing provenience (the geographic origin of the debris and the sector that is primary responsible for its release), means of release (the mechanisms by which the debris enters the marine environment), and entry points (where the release occurred) of plastic debris (Veiga et al., 2016). To bridge these gaps, existing assessment frameworks consider the annual amount of mismanaged plastic waste produced by coastal populations. In fact, it has been estimated that plastics consumed within a 50 km distance from the coast are at “high risk of entering the ocean” via direct littering, inland waterways, wastewaters, or transported by wind and tides (Jambeck et al., 2015).
This chapter explores the most common sources and pathways of plastic pollution in coastal and island regions, where mismanaged plastic waste is at the highest risk of becoming marine pollution, and it provides tangible implications and solutions to detect plastics in these areas. Coastal environments suffer particularly from plastic pollution, as they host hotspots for the production, accumulation, and release of plastic debris (Li et al., 2016). Second, coastal sites are exposed to the negative effects of plastic pollution, ranging from environmental degradation to jeopardy of marine ecosystems (Cózar et al., 2014; Lamb et al., 2018). A third element of concern is that marine pollution can impoverish local economies via reduced investments in coastal development (McIlgorm et al., 2011; Jang et al., 2014) and decline of coastal- and marine-dependent activities (e.g., fishing, mariculture, and tourism) (Mohammed, 2002; Staehr et al., 2018). In addition to the challenges experienced by coasts, islands face several barriers related to environmental management such as the limited physical space for storing and treating waste, a lack of resources to implement efficient waste infrastructure, higher waste management costs, and difficulty of implementing plastics circularity locally (Eckelman et al., 2014). Ultimately, understanding the distribution patterns of marine litter in coastal and island regions is crucial to unfold the impacts on the marine environment and root causes of marine pollution.
Key Terms in this Chapter
Litter Pathway: Physical and/or technical means by which pollution enters the marine environment and transport mechanisms ( Veiga et al., 2016 )
Plastic-Waste Leakage: Refers to the spillage of unmanaged plastic waste that originates on land and reaches the ocean ( Ocean Conservancy, 2015 ).
Microplastics: Plastic particles, 5 mm in size or smaller. Microplastics can generate in-water from the breakdown of larger plastic debris or on-land, where they are generally found in personal care products (e.g., dental hygiene products and cosmetics) or clothing ( Fendall & Sewell, 2009 ; Free et al., 2014 ).
Plastic Pollution: Is the totality of plastic accumulation in the environment. It is associated with ecological impacts and emissions from plastic production, consumption, leakages from littering practices and inefficiencies in waste management infrastructure, and impacts related to recycling and other waste treatment processes ( Nielsen et al., 2020 ).
Monitoring: Refers to an array of approaches, technologies, and instruments used to detect, map, and monitor a specific phenomenon (e.g., plastic pollution) via communication of real-time or nearly real-time data.
End-of-Life: A product reaches its end-of-life when it no longer satisfies users. End-of-life conditions may include a change in the product’s dimension from the original ones, lower cleanliness level which can negatively affect the product’s use, and reduced performance due to extensive use of the product over time ( Ng et al., 2014 ).
Litter Source: Refers to the means of release of marine litter, including the primary sectors and human activities generating plastic pollution, their geographic origin and location ( Veiga et al., 2016 ).