The science behind plastics and what we can do about it

Did you know that approximately over 350 million tons of plastic is manufactured every year and of this, among 5-13 million tons ultimately ends up in the ocean. Did you also know that the longer a plastic remains in the environment, the more it is subject to a process named degradation which is the breakdown of plastics into smaller pieces via weathering, photodegradation, and biodegradation.

When disaggregated/broken down, plastics can be categorised into several different groups: macroplastics, microplastics, and nanoplastics.

Macroplastics: Macroplastics are characterised as a plastic object larger than 5mm in diameter, which includes, but is not limited to, plastic items such as: bottles, nets, ropes and packaging. These macroplastics are responsible for the entanglement of marine life and terrestrial species. This invasion of habitat from macroplastics can lead to altered behaviour (a common example of this is seabirds utilising macroplastics for nesting), trauma, wounds and subsequently the death of individuals.

Photo by Shearer Shez Viljoan

Microplastics: Microplastics are usually characterised as plastic debris between 1μm- 5mm in diameter. Plastic particles originally manufactured within this size range are classed as primary source microplastics and are designed for use in commercial industries such as cosmetic and textiles. Microplastics resulting from the fragmentation/breakdown of larger macroplastics, are classed as secondary sources. Evidence of these microplastics has been recorded since the 1970s and has been reported worldwide, they have even been found in the most remote locations! Microplastics have been shown to cause harm to all living organisms as they are capable of interacting with many marine species ranging from zooplankton to marine mammals.

Nanoplastics: Nanoplastics are characterised as plastic particles smaller than 1μm and are formed through the breakdown process. Due to their size, nanoplastics can translocate/move through the tissues of organisms, which influences normal vital bodily processes. Nanoplastics can act as a vector for toxic chemicals to piggyback on and then translocate/move through the blood-brain barrier into the brain, leading to a range of neurotoxic effects causing changes in cognition and behaviours. Due to the challenging nanoscopic size of nanoplastics, they are difficult to detect and quantify, which is why there is a current lack of information surrounding nanoplastics.

Photo by Brian Skerry

But there is more…

Plastics also have the ability to travel through the food chain by trophic transfer. Trophic transfer is the main transfer of plastic particles through the food chain, via the various interconnected relationships of prey/predator species, which leads to the bioaccumulation and biomagnification of plastics within the food chain. Not only this but plastics have been shown to have damaging impacts on fertility, growth, reproduction, oxidative stress and the lifespan of many species. Overall, the uptake of plastics is causing negative health implications for living organisms including humans. However additional research is needed on this topic as it would help to encourage much-needed change and promote the development of environmental policies that decrease the use of plastics.

So what can you do about this?

Start by reducing single-use plastic, such as disposable water bottles, bags, and containers, and try to recycle any plastic products you do use. Become educated on plastics and the products that have microplastics contained inside of them. It can be difficult to completely cut plastic out of your everyday life, so if you already have plastic items, try re-using them.

Photo by Kuyer Fazekas Jr

At Operation Wallacea we help towards tackling marine plastic pollution in several ways. We continue to do all we can to reduce our plastic usage both in the office, at home and on expeditions. We encourage the use of non-plastic alternatives, for example, replacing everyday plastic items with environmentally friendly options like shampoo bars instead of traditional plastic shampoo bottles on expeditions. Not only this, but on many of our marine Opwall expeditions participants take part in beach and ocean cleans, this hands-on approach allows Opwall and its volunteers to directly contribute to the removal of plastic waste from the environment preventing it from further damage and harm to the environment and its inhabitants. The research conducted and data collected from Opwall expeditions are critical for understanding the impacts of pollutants such as plastics on different ecosystems and marine species’ behaviour. It contributes to the broader understanding of how to care for our oceans and its inhabitants. The research collected also informs policy and conservation efforts.