Anthropogenic Marine Debris (AMD) in the SE Pacific has primarily local origins from land-based sources, including cities (coastal and inland), beach-goers, aquaculture, and fisheries. The low frequency of AMD colonized by oceanic biota (bryozoans, lepadid barnacles) suggests that most litter items from coastal waters of the Humboldt Current System (HCS) are pulled offshore into the South Pacific Subtropical Gyre (SPSG). The highest densities of floating micro- and macroplastics are reported from the SPSG. An extensive survey of photographic records, unpublished data, conference proceedings, and published studies revealed interactions with plastics for 97 species in the SE Pacific, including 20 species of fish, 5 sea turtles, 53 seabirds, and 19 marine mammals. Sea turtles are most affected by interactions with plastics, underlined by the fact that 4 of the 5 species suffer both from entanglement and ingestion. Reports gathered in this review suggest that interactions along the continental coast are mostly via entanglement. High frequencies of microplastic ingestion have been reported from planktivorous fish and seabirds inhabiting the oceanic waters and islands exposed to high densities of microplastics concentrated by oceanic currents in the SPSG. Our review also suggests that some species from the highly productive HCS face the risk of negative interactions with AMD, because food and plastic litter are concentrated in coastal front systems. In order to improve the conservation of marine vertebrates, especially of sea turtles, urgent measures of plastic reduction are needed.
Bibliographical noteFunding Information:
We would like to thank all citizen science observers for contributing their photographic records about entanglement. We are especially grateful to all our colleagues for freely sharing their insights, unpublished observations, and images that significantly enhanced the scientific value of this contribution. Two reviewers provided many helpful suggestions and Annie Mejaes kindly revised the English of the final manuscript. This project received support from the Chilean Millennium Initiative to ESMOI (Millenium Nucleous Ecology and Sustainable Management of Oceanic Islands). Sampling of floating plastics in the South Pacific was funded by the Comité Oceanográfico Nacional (CONA) from Chile, project codes CONA C21-15-029 and CONA C22-16-11 to MT; and project codes CONA C21-15-113 and CONA C22-16-06 to GL-J. NO received support through a postdoctoral FONDECYT grant (No. 3150636) and NM received support through the CONICYT Beca Doctorado Nacional No 21151143, and NL received support from Beca Magister Nacional CONICYT No 22161894 from the Chilean Ministry of Education. Shark interactions with plastics were observed during the project entitled The lost fish from Easter Island funded by Save Our Seas Foundation Small Grant No 61.
© 2018 Thiel, Luna-Jorquera, álvarez-Varas, Gallardo, Hinojosa, Luna, Miranda-Urbina, Morales, Ory, Pacheco, Portflitt-Toro and Zavalaga.
- Anthropogenic marine debris
- Biota-litter interactions
- Microplastic ingestion