In Looe – a coastal community in Cornwall reliant on summer visitors for survival – plastics enter the river during the summer season at an alarming rate. Takeaway coffee cups, plastic bottles, brightly coloured crab-nets and neon ice cream spoons pile up on the harbour side awaiting the rains and tidal floods to sweep them off to add to the harmful afterlife plastic is having in our oceans.
From Miracle Material to Pernicious Problem
Amazingly it has been less than century since the beginning of plastic production, yet plastic debris can be found in every marine environment, from bags in the depths of the ocean to potentially carcinogenic plastic micro-fibres floating in the air of city streets (1).
Plastic isn’t ‘bad’ or ‘good’ – it is a both wonder material, strong, light and resistant (hence why it lasts) and without it we wouldn’t have a lot of things we rely on everyday. The problem is our over-use and poor disposal of it, which isn’t so wonderful.
Don’t just take our word for it, here are the facts: of the 6300 million tonnes of plastic waste generated between 1950-2015 globally, 9% has been recycled, 12% incinerated and 79% has been disposed of in the natural environment (and despite increasing awareness, by 2050 the amount of plastic waste is only set to increase (2)).Lots of the plastic in our oceans is from single use packaging and products. Why do companies use excessive amounts of plastic in disposable packaging and products? Well, plastic packaging is cheap and robust and using it allows companies to keep items on shelves longer saving them money, as plastic keeps things fresh and doesn’t degrade easily itself (its companies and consumers wanting non-degrading products that led to the ‘ever-lasting’ plastics in our seas). It is only cheap because they don’t have to pay the cost of clearing it up, we do. If we stop buying over-packaged products companies will stop selling them.
The consequences of this plastic soup we are creating has poorly understood consequences for our health – from being linked to a widespread rise in male infertility to forms of cancer. The consquences for wildlife, especially in our oceans though are clearly dire (3, 4, 5, 6, 7).
The exact effects of plastics depend on their size
Plastic is classified as either macro-plastics, which is plastic debris that is visible to the eye or as micro-plastics which are often impossible or difficult to see and are classified as under 5mm (8, 9).
Macro-plastics areresistance to deterioration, brightly-coloured mimicking the food of wildlife and are often purposely shaped into nets to capture fish. As a result of these characteristics they damage a spectrum of marine creatures due to ingestion, entanglement and choking, which are documented in a range of marine mammals, seabirds, turtles, corals and fish (10).
Micro-plastics are more insidious – reminiscent of radioactive fallout after a nuclear accident, but sadly far more prevalent. Micro-plastics are produced either naturally through erosion of large pieces of plastic, or by man for use as micro-beads (in facial scrubs, toothpaste and shower gels). Most microplastics come from fibres come of our clothes in washing (find out more about microfibres here). The United Nations estimates that there is over 500 times as many micro-plastic particles in the ocean as stars in our own galaxy – over 50 trillion micro-plastic particles!
Many types of plastic when they enter the ocean break down into micro-plastics, which look exactly like plankton. Micro-plastics are easily absorbed into fatty tissues and due to their persistence accumulate through the food chain, as microbes are eaten by plankton, who are eaten by fish and so. Micro-plastics impacts therefore are worst on predatory species because of a process called biomagnification – which magnifying pollutants negative effects on animals higher up the food chain (11, 12 , 13).
These microplastics often get eaten, entering the food chain and eventually end up on our plates in seafood- which is worrying because they readily absorb other toxic pollutants – which means that predatory species such as sharks, mackerel, tuna and seals, have much higher amounts of plastics and associated pollutants in their tissues than we would expect from direct exposure to polluted waters alone. This is troubling as we humans are the apex predators of nearly every modern marine food chain and therefore these toxins can pose a significant health risk for those who consume them (Zarfl and Matthies, 2010).
What Behaviour Change Cornwall has already done to help
To reduce the amount of plastic accumulating in our ocean we must identify the exact behaviours that result in plastic entering the ocean – understanding the psychological and contextual factors that drive these actions – and then use this new behavioural knowledge instigate an adoption of new practices that end the flow of plastics into the environment.
To this aim our Living Lab in Looe project tried to better understand why plastic is ending up as litter and whether psychologically-smart signs nudge visitors towards better behaviour along the harbour quayside in Looe, Cornwall.
The hope is that we can find more effective solutions to the environmental challenges Cornwall and the rest of the world faces. The insights gained will also help any community, business or organisation experiencing environmental problems due to the behaviour of visitors, who are often not invested in the long-term health of the environmental places they visit, helping coastal communities to make signage that is targeted and effective reducing the tide of plastic entering our oceans.
We found this Spider Crab foraging in still water full of floating seaweed and plastic, whilst Freediving off Plaidy. Her shell, which is covered in seaweed had pieces of plastic fishing line imbedded into it which we managed to remove.
- Barnes, D.K., Galgani, F., Thompson, R.C. and Barlaz, M. (2009). Accumulation and fragmentation of plastic debris in global environments. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1526), pp.1985-1998.
- Geyer, R., Jambeck, J.R. and Law, K.L. (2017). Production, use, and fate of all plastics ever made. Science advances, 3(7), p.e1700782.
- Beaumont, N.J., Aanesen, M., Austen, M.C., Börger, T., Clark, J.R., Cole, M., Hooper, T., Lindeque, P.K., Pascoe, C. and Wyles, K.J., 2019. Global ecological, social and economic impacts of marine plastic. Marine pollution bulletin, 142, pp.189-195.
- Derraik, J.G., 2002. The pollution of the marine environment by plastic debris: a review. Marine pollution bulletin, 44(9), pp.842-852.
- Halden, R.U., 2010. Plastics and health risks. Annual review of public health, 31, pp.179-194.
- Provencher, J.F., Ammendolia, J., Rochman, C.M. and Mallory, M.L. (2018). Assessing plastic debris in aquatic food webs: what we know and don’t know about uptake and trophic transfer. Environmental Reviews, (999), pp.1-14.
- Mouat, J., Lozano, R.L. and Bateson, H., 2010. Economic impacts of marine litter. Kommunenes Internasjonale Miljøorganisasjon.
- Hartmann, N.B., Hüffer, T., Thompson, R.C., Hassellöv, M., Verschoor, A., Daugaard, A.E., Rist, S., Karlsson, T., Brennholt, N., Cole, M. and Herrling, M.P., 2019. Are we speaking the same language? Recommendations for a definition and categorization framework for plastic debris.
- Arthur C., Baker, J. and Bamford, H. (2009). “Proceedings of the International Research Workshop on the Occurrence, Effects and Fate of Microplastic Marine Debris”. NOAA Technical Memorandum
- Gregory, M.R., 2009. Environmental implications of plastic debris in marine settings— entanglement, ingestion, smothering, hangers-on, hitch-hiking and alien invasions. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1526), pp.2013-2025.
- Tanaka, K., Takada, H., Yamashita, R., Mizukawa, K., Fukuwaka, M.A. and Watanuki, Y. (2013). Accum ulation of plastic-derived chemicals in tissues of seabirds ingesting marine plastics. Marine pollution bulletin, 69(1-2), pp.219-222.
- Rochman, C.M., Browne, M.A., Halpern, B.S., Hentschel, B.T., Hoh, E., Karapanagioti, H.K., Rios-Mendoza, L.M., Takada, H., Teh, S. and Thompson, R.C., 2013. Policy: Classify plastic waste as hazardous. Nature, 494(7436), p.169.
- Rochman, C.M., Hoh, E., Kurobe, T. and Teh, S.J. (2013). Ingested plastic transfers hazardous chemica ls to fish and induces hepatic stress. Scientific reports, 3, p.3263.
- Zarfl, C. and Matthies, M. (2010). Are marine plastic particles transport vectors for organic pollutants to the Arctic?. Marine Pollution Bulletin, 60(10), pp.1810-1814.