Marine Plastic Pollution: The Threat Pervading Australia’s Waters

Water availability and ecosystem environments have become of increasing concern as more and more contaminants are leaching into natural waterways. A study conducted by the University of Western Australia and CSIRO sought to determine the composition and pathways of some of the most harmful physical contaminants: plastics.

The team characterized and estimated concentrations of marine plastics around Australia using a new-towing method, which would allow inference for potential pathways of plastic pollution. They used three consecutive 15-minute net tows at 57 different locations around Australia, and chose a random sample of 200 collected pieces for polymer composition analysis. Of these 200 pieces, 67.5% were made of polyethylene, 31% from polypropylene, 1% from expanded polystyrene and 0.5% ethylene vinyl acetate.  There was also shown to be an inverse relationship between concentration of these contaminants and wind forcing, where higher plastic concentrations were observed in areas with lower winds. 

Julia Reisser and her team found that a majority of the plastic pieces sampled had low circularity in their shape as compared to manufactured products, lending to the idea that they’re the result of degradation from larger plastics. Micro-plastics, they found, were the most common type of debris, and most commonly came from hard plastics. These plastics most commonly accumulate at the surface, but lose buoyancy over time due to biofilm buildup. This lower water permeation of small plastics opens up the discussion on toxic effects to marine life: it has been shown that these particulates adversely affect not only fish, but also large marine vertebrates such as baleen whales. Australia is a particularly interesting study location, as the plastics observed in the study can be moved fairly easily around the country. Both isolated and populated locations are at risk, as many different currents allow for plastics to readily flow: Antarctic Circumpolar current, South Equatorial current, East Australia current, West Australia current and a few other coastal current systems all move plastics to aggregation spots around the coast. Because of this breadth of sources, regulation of waste from plastic would be rather difficult to employ and enforce. The authors of the study suggest more “sea-studies on characterization, spatial distribution, and pathways of marine plastics in coastal and oceanic regions… as well as on marine plastic toxin loads and interactions…” to improve our knowledge of the pollution, and make more apparent the need for more stringent regulation.

Overall, I think the article from The Guardian fulfilled its goal: it brought attention to an important environmental pollution issue that needs to be dealt with. However, when presenting the findings of the study, they omitted almost all of the research and instead filled it with quotes from the primary author. While still informative, I believe it would have been more impactful to have taken some of the conclusions from the study to give weight to the severity of the subject.

The Guardian article:

http://www.theguardian.com/environment/2013/nov/28/marine-plastic-pollution-the-threat-pervading-australias-waters

PLOS ONE article:

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0080466#authcontrib