Plastic pollution in the Coral Triangle

Recently a group of second and third year science students from the University of Adelaide travelled to Timor Leste as part of an Australian government New Colombo Plan funded trip. Over the next few weeks we will be showcasing several of their graphics and short essays. The graphic and essay that follows is by Fiona McQueen, a third year BSc (Advanced) student.

The Coral Triangle (CT) consists of the area of the Pacific Ocean surrounded by Indonesia, the Philippines, Timor Leste, Malaysia, the Solomon Islands and Papua New Guinea. Containing 30% of the world’s coral reefs, it’s considered the richest place on earth for biodiversity (WWF, 2016). This region is at risk from consequences of anthropogenic activities – one of the most apparent is plastic pollution.

Eight million metric tons of plastic are estimated to enter the oceans each year (Jambeck 2015). Estimated to take hundreds of years to break down, the durability of plastic coupled with buoyancy facilitating long distance dispersal, makes for a successful polluter (Pruter 1987, Laist 1987). Moore (2008) defined two forms of plastic pollution – macro (plastic pieces >5mm diameter) and micro (<5mm diameter). Macroplastic is most obvious – e.g. plastic bottles washed up on beaches, whereas microplastic less so, but no less damaging and often the product of macroplastic breaking up into smaller fragments. Increasing human populations has increased plastic use; particularly single use plastic, resulting in massive amounts of plastic thrown out to landfill or directly into the environment each year.

Ingestion of macroplastic by marine mammals and turtles has been widely documented (Bjorndal 1994, Jones, 1995, Moore, 2008), with anything from bottle lids to whole sheets of plastic found in stomachs and intestinal tracts of these organisms. Hall (2015) found corals ingest microplastic, mistaking it for prey, and suggested high concentrations of microplastic in the coral gut cavity impairs coral health. Reduction in healthy coral populations would detrimentally affect the persistence of the ecosystem, having consequences for organisms that rely on the reef for food and shelter, and for the 130+ million people relying on it for their main source of protein (Cros ., 2014, Foale 2013). Fish and other filter feeders also ingest microplastics, remaining in their stomachs, where chemicals in the plastic are assimilated into body tissue (Rochman, 2015). This creates problems not only for the organisms, but for the people who eat these fish.

Indonesia, the Philippines, China, Thailand and Vietnam, account for 60% of the annual oceanic plastic input (Ocean conservancy, 2015). With these countries all in close proximity to the Coral Triangle, plastic pollution is a significant issue for this region. The main source of ocean plastic is land based – plastic leaked from landfill and littering accounts for 80% of it (Ocean conservancy, 2015). Poor waste management systems contribute to this – in Timor-Leste, household waste collection consists of uncontained concrete pits prone to spill over (Asian Development Bank, 2014). A lack of knowledge about the consequences of littering means the cultural attitude is to throw rubbish on streets and in drains.

Introducing plastic recycling and overall better waste management to the countries of the Coral Triangle is imperative to reduce future pollution. Arguably more important though is educating the community on appropriate waste management and the consequences of failing to do so because, from knowing comes caring, and from caring comes change.


Asian Development Bank, (2014). Solid Waste Management in the Pacific – Timor-Leste Country Snapshot. Publication Stock No. ARM146615-2

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Foale, S, Adhuri, D, Alino, P, Allison, E, Andrew, N, Choen, P, Evans, L, Fabinyi, M, Fidelman, P, Gregory, C & Stacey, N (2013). Food Security and the Coral Triangle Initiative. Marine Policy, vol. 38, pp. 174-183.

Hall, N. M., Berry, K. L. E., Rintoul, L., & Hoogenboom, M. O. (2015). Microplastic ingestion by scleractinian corals. Marine Biology, 162(3), 725-732.

Jambeck, J.R., Geyer, R., Wilcox, C., Siegler, T.R., Perryman, M., Andrady, A., Narayan, R. and Law, K.L., (2015). Plastic waste inputs from land into the ocean. Science, 347(6223), pp.768-771.

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Laist, D. W. (1987). Overview of the biological effects of lost and discarded plastic debris in the marine environment. Marine pollution bulletin, 18(6), 319-326.

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Ocean Conservancy, (2015). Stemming the tide: Land-based strategies for a plastic-free ocean. McKinsey centre for business and Environment.

Pruter, A. T. (1987). Sources, quantities and distribution of persistent plastics in the marine environment. Marine Pollution Bulletin, 18(6), 305-310.

Rochman, C. M., Tahir, A., Williams, S. L., Baxa, D. V., Lam, R., Miller, J. T., ... & Teh, S. J. (2015). Anthropogenic debris in seafood: Plastic debris and fibers from textiles in fish and bivalves sold for human consumption. Scientific reports, 5.

WWF, (2016). Coral Triangle. <>. Viewed 23 July 2017.