Plastic Pollution and Marine Megafauna: Recent Advances and Future Directions

Nelms SE, Clark BL, Duncan EM, et al (2022) Plastic Pollution and Marine Megafauna: Recent Advances and Future Directions. In: Plastic Pollution in the Global Ocean. WORLD SCIENTIFIC, pp 97–138

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The widespread and pervasive nature of plastic pollution has resulted in a growing body of evidence documenting the detrimental effects of anthro-pogenic waste on aquatic wildlife (Provencher et al., 2017; Kühn & van Franeker, 2020). Over the last two decades, the number of marine species known to ingest or become entangled in debris, of which the majority is plastic, has more than trebled from 267 (Laist, 1997) to 914 (Kühn & van Franeker, 2020).

Of particular concern are marine megafauna, namely, marine mam-mals (cetaceans, pinnipeds, sirenians and the polar bear), elasmobranchs (sharks and rays), marine turtles and seabirds. These large marine vertebrates play key roles in the functioning and maintenance of marine habitats and are often considered indicators of marine ecosystem health (Alves et al., 2016; Pimiento et al., 2020). They also provide economic, social and cultural benefits and serve as flagship species for enhancing public engagement in marine conservation issues (Frazier, 2005; Germanov et al., 2018). Despite this, many marine megafauna species face a range of anthropogenic pressures, including fisheries (direct take and by-catch), climate change, habitat loss and pollution (Pimiento et al., 2020; Nelms et al., 2021), one-third are considered vulnerable to extinc-tion as a result (Pimiento et al., 2020).

The recently emerged threat of plastic pollution presents an addi-tional and omnipresent issue for these species; as the volume of anthro-pogenic debris circulating within the global ocean increases, so too does the likelihood of its interaction with marine wildlife. Indeed, plastic pollution is now so ubiquitous that even species residing in remote habi-tats, such as the polar regions, are exposed to it (Bergmann et al., 2017; Bessa et al., 2019). Currently, all seven marine turtle species, 70% of marine mammal species, and 55% of seabird species are known to inter-act with anthropogenic debris through ingestion and entanglement (Kühn & van Franeker, 2020). These numbers are likely to grow further still due to the recent increase in attention from the scientific community and general public in plastic pollution. Notably, elasmobranchs have been missing from previous assessments but are beginning to receive greater attention as evidence of interactions with plastic pollution emerges (Abreo et al., 2019; Germanov et al., 2019b, Mucientes & Queiroz, 2019; Parton et al., 2019, 2020).