Data from: Marine plastic pollution in waters around Australia: characteristics, concentrations, and pathways

Plastics represent the vast majority of human-made debris present in the
oceans. However, their characteristics, accumulation zones, and transport
pathways are still poorly assessed. We characterised and estimated the
concentration of marine plastics in waters around Australia using surface
net tows, and inferred their potential pathways using particle-tracking
models and real drifter trajectories. The 839 marine plastics recorded
were predominantly small fragments (“microplastics”, median length = 2.8
mm, mean length = 4.9 mm) resulting from the breakdown of larger objects
made of polyethylene and polypropylene (e.g. packaging and fishing items).
Mean sea surface plastic concentration was 4256.4 pieces km-2, and after
incorporating the effect of vertical wind mixing, this value increased to
8966.3 pieces km-2. These plastics appear to be associated with a wide
range of ocean currents that connect the sampled sites to their
international and domestic sources, including populated areas of
Australia’s east coast. This study shows that plastic contamination levels
in surface waters of Australia are similar to those in the Caribbean Sea
and Gulf of Maine, but considerably lower than those found in the
subtropical gyres and Mediterranean Sea. Microplastics such as the ones
described here have the potential to affect organisms ranging from
megafauna to small fish and zooplankton.