Naslov
Marine plastic pollution in Vava’u archipelago, Tonga

Autori
Markic, Ana ; Bridson, James H. ; Morton, Peta ; Hersey, Lucy ; Budiša, Andrea ; Maes, Thomas ; Bowen, Melissa

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, neobjavljeni rad, znanstveni

Skup
7IMDC 7th International Marine Debris Conference

Mjesto i datum
Busan, Republika Koreja, 18.09.2022. - 23.09.2022

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Marine plastic pollution ; surface waters ; sediments ; Tonga

Sažetak
Although plastic pollution research on a global scale considerably intensified in the current decade, research effort in the South Pacific is generally still lacking. We carried out a study on plastics contamination of the surface waters and shore and benthic environment, on macroscopic and microscopic level, in Vava’u archipelago, Tonga. This is the first study on microplastic pollution in all three marine environmental compartments in the Pacific islands. As well as a baseline, the study also focused on methodological advancement. On the macroscopic level, we found plastic debris larger than 1 mm in greater concentrations along in the intertidal (0.8 ± 0.3 item m-2) than in the subtidal (0.02 ± 0.01 items m-2). Microscopic assessments of surface waters revealed high concentrations (337, 812.5 ± 42, 044.5 pcs km-2 or 1.08 ± 0.13 pcs m-3). Instead of the standard 300- micron sampling nets, for sample collection we used a finer plankton net (100 µm) in order to determine the proportion of captured microplastics smaller than 300 µm, which turned out to be 40 % of all surface particles. Microplastics in intertidal and subtidal sediments were present in concentrations of 31.2 ± 5.5 and 15.0 ± 1.9 particles per 1 L of sediment, respectively. To isolate microplastics from the sediments by density separation technique, we used calcium chloride (CaCl2) for a high-density solution (ρ = 1.40 – 1.45 g cm-3). The most dominant type of microplastics in the sediment samples were fibres. In the surface waters predominant were small bits of white film which we associated with white construction material, visibly eroded on most parts, used for building docks in Vava’u. Our study shows that the levels of plastic pollution in Vava’u archipelago are among the greatest recorded in the South Pacific.

Izvorni jezik
Engleski

Znanstvena područja
Interdisciplinarne prirodne znanosti

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