Marine debris: Are there solutions to this global environmental problem?

29 April 2018 - By: Shanice Fagan & Shonagh Bell

Marine debris: Are there solutions to this global environmental problem?

By Shanice Fagan and Shonagh Bell

Richard Thompson, a professor at Plymouth University and an expert in the field of microplastics, recently delivered a public lecture at the University of the West of Scotland, sponsored by the Society for Environmental Biology. Here Shanice Fagan and Shonagh Bell, two undergraduate students from University of West Scotland present their perspectives on the lecture.

Litter in the ocean is a growing problem and, while it consists of a variety of substances, the majority of marine litter is plastic. Plastic waste has now been found in all areas of the ocean, including in previously unexplored areas of deep sea. Plastic can be found in a range of sizes from macroplastics to microplastics, with an estimated 17MT entering the environment annually.

Professor Thompson explained the potential threat to wildlife that plastic waste poses - with more than 300 scientific papers published on the subject, 700 species which encounter plastic waste have been identified, 17% of which are threatened or near threatened. Seabirds are a particular cause for concern with many species found entangled in plastic debris or with plastic in their digestive system. However, the fact that a species encounters plastic waste is not conclusive evidence that it causes harm; Professor Thompson highlighted the need for research that seeks to understand the actual harm caused by plastics.

An interesting discussion point of the seminar was whether plastic materials are intrinsically ‘bad’. In fact, plastic is a very practical material; it is cheap to manufacture and offers many benefits. For example, its ability as packaging to extend the life of food and drink reduces the global problem of food wastage. For around 60 years, however, plastic has been developed and marketed as disposable. It is this ‘throw-away’ attitude towards convenience plastics which Professor Thompson believes is at the heart of the problem. If current trends persist, by 2025 we could be experiencing three times the volume of plastic pollution compared to today.

A common answer to the problem of plastic waste is recycling. Recycling can re-direct the flow of plastics after use but relies on several factors to be successful. Firstly, the product needs to be designed so that not only can it be recycled, but also so that it is cost-effective for the recycler. For instance, the coloured dye added to plastic drinks bottles significantly reduces their ease of recycling. Professor Thompson believes that effective labelling, such as a traffic light system indicating the impact of the packaging on the environment, could be used to raise awareness in consumers and drive companies to look for alternative, environmentally-friendly materials for packaging.

Biodegradable plastic is another proposed solution. It is important to remember, however, that one of the most useful traits that plastic has is its durability. Any packaging which biodegrades enough to cause no harm to the environment is likely to be of little use for packaging. Additionally, many products which are labelled as ‘biodegradable’ either require extreme conditions never encountered in a natural environment to degrade or result in the same amount of plastic waste but in a fragmented form. Even a small amount of biodegradable material mixed in with non-biodegradable plastic can be detrimental for recycling.

In conclusion we learnt that there is no simple solution to this global environmental problem. What is clear is that plastic itself is not the enemy; we must move away from our ‘throw-away’ culture and apply pressure to companies to design products with an end-of-life strategy that minimises environmental impact while allowing the benefits of plastics to be retained.
Category: Animal Biology