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.
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 my 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)).
Macro-plastics are resistance 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).
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 this 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. Her shell, which is covered in seaweed had pieces of plastic fishing line imbedded into it.|
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