Figure 1.
Sampling locations of the 68 plastics analyzed in this study.
Black lines delimit marine regions of Australia (environment.gov.au/topics/marine/marine-bioregional-plans); dots indicate areas where the analyzed plastics were collected; numbers represent how many plastics were taken for scanning electron microscopy analyses at these locations. Samples collected were fragments of hard plastic (N = 65), except at locations marked with an asterisk: one piece of Styrofoam cup in Fijian waters, one pellet in South Australia, and one piece of soft plastic in the Australia’s North-west marine region.
Figure 2.
Overall appearance of marine plastics, as shown by scanning electron micrographs.
Dot color indicates the marine region where the piece was sampled (see legend and Figure 1). Pieces are hard plastic fragments, with the exception of the soft plastic fragment (red dot), pellet (yellow dot), and Styrofoam fragment (green dot) shown at the bottom of the diagram and marked with a white asterisk. All images are at the same magnification (see scale bar at lower right).
Figure 3.
Types of epiplastic organisms detected at each of the marine regions sampled in this study (see Figure 1).
Lines connect types of organisms (squares) to the marine regions (circles) where they were observed. Line color indicates type of organism, with black lines representing invertebrates. Line thickness is proportional to the organism’s frequency of occurrence (FO = <25%, 25–50%, 50–75%, >75%).
Figure 4.
Examples of epiplastic diatoms.
a: Navicula sp.; b: Mastogloia sp.; c: small naviculoids; d: Nitzschia sp.; e: Nitzschia sp.; f: Nitzschia longissima.; g: Cocconeis sp.; h: Cocconeis sp.; i: Achnanthes sp.; j: Thalassiosira sp.; k: Thalassionema nitzschioides; l: Microtabella sp.; m: Amphora sp.; n: Amphora sp.; o: Licmophora sp.
Figure 5.
Examples of epiplastic coccoliths and dinoflagellate.
a: Calcidiscus leptoporus; b, c: Emiliania huxleyi; d: Gephyrocapsa oceanica; e: Umbellosphaera tenuis; f: Umbilicosphaera hulburtiana; g: Coccolithus pelagicus; h: Calciosolenia sp.; i: Ceratium cf. macroceros dinoflagellate.
Figure 6.
Examples of epiplastic rounded, elongated and spiral cells.
a, b, c: rounded cells; d: spiral “spirochaete” cell; e, f, g, h: elongated cells.; i, j, k, l, m: pits and grooves on plastics with rounded cells.
Figure 7.
Examples of epiplastic invertebrates.
a: Bryozoan colony harboring an abundant assemblage of Nitzschia longissima (zoomed image shows part of this assemblage, scale bar = 20 µm); b: bryozoan colony relatively free of fouling; c: bryozoan-plastic interface displaying an abundant epizoic assemblage of Amphora sp.; d: bryozoan-plastic interface displaying an abundant epizoic assemblage of Nitzschia sp.; e, f: barnacles (Lepas spp.); g: Asellota isopod; h: egg of the marine insect Halobates sp.; i: marine worm; j: zoom on the surface of the unidentified marine worm.
Table 1.
List of known genera occurring on millimeter-sized pelagic plastics.