Research CentreWorld Oceans Day 2020

Ocean Plastic: Why prevention is better than cure

By May 15, 2020June 4th, 2020No Comments
© Jambeck et al. 2015

While the removal of ocean plastic should continue to be pursued, the scope and very nature of the issue calls for a more economically viable solution through recycling.

Following a rise in scientific data about ocean plastic pollution, finding ways to reduce it has become increasingly important. Perception of abundance and environmental credibility has made the use of ocean plastic in products and packaging a lucrative option for businesses too. Though the realities of recycling ocean plastic are complex, preventing ocean plastic through recycling remains one of the most viable ways of reducing ocean plastic pollution.

What is Prevented Ocean Plastic?

The term Prevented Ocean Plastic is derived from a study delivered by Jenna Jambeck, professor at the University of Georgia, who estimated the amount of plastic waste entering the ocean from land-based sources. Following the study’s framework, Prevented Ocean Plastic is found within 50km of an ocean coastline or major waterway that feeds into the ocean. It is collected in countries and regions lacking in effective waste management infrastructure that in addition, is overwhelmed by population growth or tourism.

The results of this study indicated that approximately 4.8 – 12.7 million metric tonnes of plastic entered the ocean from land in 2010. However, it remains unclear as to what fraction of total plastic waste this represents, as the total estimate of other plastic waste sources entering the ocean remains unknown. Other figures, such as those from a study estimating the total amount of ocean debris in the five ocean gyres are significantly less. Though the concentrations ranged considerably, the same study indicated that 88% of the ocean surface contained plastic. Yet these numbers reflect only just a fraction of plastic waste as they only account for what is floating near the surface.

A sinking problem

Recently, a study carried out by Dr. Ian Kane from the University of Manchester once again illustrated that a vast majority of plastic that ends up in the ocean sinks to the bottom. Microfibers which seep through washing machines and water waste systems are moved around by bottom ocean currents which also supply valuable nutrients and oxygen to biodiversity hotspots – the impacts of which are unknown but likely damaging. A similar fate is known to await larger items of plastic debris which break down into smaller pieces over time. Highlighted in a much earlier study collecting samples across the United Kingdom, researchers uncovered microscopic plastic in plankton samples dating back to the 1960s.

©University of Manchester, Dr. Ian Kane

The realities of recycling ocean plastic

While there are various waste routes into the ocean, it is the removal of plastic debris, microscopic or not, which remains both an economic and grossly logistical challenge. The longer the plastic remains in the ocean, the more difficult it is to collect due to moving ocean currents and degradation. Hence, the less suitable the plastic material becomes for recycling. According to the director of Foplam, Alvaro Aguilar, “Plastic which is exposed to the sun and saltwater turns yellow, hard and brittle and such degradation makes ocean plastic unusable for recycling.” Although removing marine debris remains important, upon reaching land, this type of plastic will likely be incinerated or placed in a landfill because it is simply too costly to recycle. It is thus critical that plastic is prevented from entering the ocean in the first place.

While there is no one-size-fits-all solution to ocean plastic, preventing even more plastic from entering the ocean is the most logical course of action. The logistical implications of removing debris across and below unthinkable depths is mind boggling. Furthermore, preventing ocean plastic would give this valuable material a chance to be recycled properly into high quality resin, keeping it in the circular economy for the benefit of the environment.