Plastic seems to be the big issue of 2018. With supermarkets charging for plastic bags and calls for reduced plastic use in food packaging, it appears that the biggest changes can be made by supermarkets and industries. But what damage is all this plastic doing to our ecosystems and how can we as consumers make an impact? It turns out all the plastic that we waste comes back in the form of a different, hidden threat; microplastics.
I have spent the summer analysing the quantity and size of microplastics in the gastrointestinal tract of marine megafauna in the Aegean Sea, Greece, to try and find the answers to these questions.
First, what are microplastics and how do they affect the ecosystem? A microplastic is any plastic ranging from 0.5mm-5mm in size, anything bigger is considered a macroplastic and anything smaller is a nanoplastic. Microplastics damage the ecosystem through a process known as adsorption. Often toxic chemicals, such as heavy metals and organic compounds, stick to the microplastic in the water. When the microplastic gets ingested by an organism, the toxin then disperses into the body of the organism and accumulates most commonly in the fat of the animal. We know that these types of toxins – mercury, for example – can cause a wide range of effects like enzyme inhibition, to name one. If biomagnified through the food chain onto our plates, mercury is a carcinogen and can cause devastating effects to the cardiovascular system. In the ecosystem, the accumulation of toxins in marine megafauna could be causing deaths and strandings, however, the effects of microplastics in marine organisms are largely unknown at this point.
If microplastics are having an adverse effect on the ecosystem we haven’t got long to come up with a solution. Microplastics are produced by macroplastics, such as shopping bags and food packaging, which broken down by phytodegradation, photodegradation (through plants or light), weathering processes or digestive break down into ever smaller and smaller pieces. As a result, microplastics never actually leave the ocean, they only accumulate. The ocean is so massive that a large-scale operation to remove or negate the effects of microplastics will take a lot of time, planning and labour. The more knowledge we can collect about the behaviour and consequences of these tiny particles, the quicker and more efficiently we can act.
We, as consumers, can have a big impact on stopping the manufacture of plastic at its source. Supermarkets produce tonnes of plastic a year to wrap food and other products. By buying plastic free vegetables and fruit, shopping at local plastic free stores and writing to your local supermarket and MP to reduce plastic usage you can have an effect. You can change the amount of plastic that enters our waterways and pollutes the ocean. We need to cut down on our plastic usage, and we need to do it quickly, otherwise, our oceans will become oceans of plastic.
Image credit: Adege via Pixabay