EXPERT REACTION: 170 trillion bits of plastic are floating on the world’s oceans thanks to 'unprecedented' increase

This week’s PLOS ONE paper by Marcus Eriksen and others on the growing plastic smog should further raise the alarm that plastic is far from fantastic.

Using samples from 11,000 ocean sites, including the Australian coastline, the authors report a concerning rise in ocean plastic since 1990 and a rapid increase since 2005.

Scientists had estimated between 93,000 and 578,000 tonnes of plastic in the ocean. The new estimate, of up to 5 million tonnes of plastic particles, is the equivalent weight of 100 Titanics.

Microplastics are an emerging contaminant in the world’s oceans, breaking down from larger plastic waste (including bags, bottles and cigarette butts). Our oceans (including seafood) are seething with disintegrating plastic particles. Plastic nanoparticles are particularly dangerous, as they can penetrate almost any body part, including the brain. Nanoparticles can cause harm over alarmingly long timescales.

Without urgent international action, the rate of plastics entering oceans will increase 2.6-fold by 2040. Dangerous plastic chemical emissions cross international boundaries, so we need a global plan. We must act now to protect ourselves, the planet and future generations.

Evidence on the environmental and human health issues related to plastic exposure is mounting. It is pivotal to have a precise, time series data on plastic pollution. This article adds timely data that will be helpful to improve the accuracy of the risk and implement management measures.

This study suggests that there is much more plastic pollution floating in the oceans than we previously thought. This means that we have been underestimating the scale of marine plastic pollution. This study shows us how big the problem really is. 

Many pieces of ocean plastics are microplastics, measuring less than half a millimetre in diameter. Many beachgoers will have seen microplastics washed up on our beaches – some microplastics are big enough to see with the naked eye, but many are so small that they are difficult to see without a microscope. 

Microplastics are a problem because they are mistaken for food and eaten by small marine animals, like mussels, oysters, and shrimp. Once eaten, microplastics can wreak havoc on an animal’s internal tissues. Microplastics interfere with the production of digestive enzymes in the stomach, damage the intestines, and leak potentially harmful chemicals inside animals’ digestive tracts. 

The study shows that the number of ocean plastics has rapidly increased since around 2006. Some of this pollution is due to our consumer choices: every piece of plastic we dispose of has the potential to escape from waste streams and enter our oceans, where it fragments into countless microplastics that harm marine life.

The numbers in this new research are staggeringly phenomenal and almost beyond comprehension. The mind boggles imagining what 4.9 million tonnes of plastic would look like. Globally, we have reached a point where we can no longer ignore the plastic pollution pandemic that is infecting our oceans.

This research shows us that beach clean-ups and citizen science projects that focus on the environmental fate of plastics have little impact on solving the enormity of the plastic problem. It is time for policymakers, governments, and businesses to wake up and take the issue seriously. Solutions that are applied across the material lifecycle are the only way to solve the plastic pollution crisis and prevent more loss to the environment.

This study is part research and part call-to-action on the issue of plastics in the oceans. We have known for some time that the amount of plastic in the ocean is increasing, and this paper gives an idea of just how much. The authors have been pretty thorough, and I think their modelling approach is a useful way of trying to understand the potential scale of the problem. I also liked how they showed that in the past policy interventions were successful, to some extent, in reducing the amount of plastic ending up in the Ocean.

While the headline about 170 trillion particles sounds, and to some extent is, scary, as the authors rightly point out, this work is a best guess. There are large variations in the model due to a lack of data from parts of the world and some limitations in the statistical methods used.

The work also only reports on how much plastic might be present over time, it doesn’t attempt to assess what effects they may have.

Much as we tend to hate on plastics, we might also remember that they are made for a reason, and they do have benefits. They protect our food from spoilage for instance and insulate our homes, and, while we don’t do a good job of it, they can be recycled. 

That said, I do agree with the authors that plastics in the environment is an important issue that isn’t going away and as such is something that the global scientific community, industry, and politicians should start to work together on solving sooner rather than later.

This is a well-designed global study that analyses data on ocean plastics over the last four decades. Since 2005 there has been a rapid and consistent increase in the amount of plastic measured at the surface of the ocean. Prior to 2005 there were no clear trends, and before 1990 there was relatively little data available.

The latest estimate (for 2019) was 170 trillion plastic particles; that is the equivalent of 500,000 elephants floating in our oceans worldwide. Without significant intervention, we can expect this number to increase. 

What’s particularly concerning is that most of these particles are microplastics. As well as being a physical danger to marine life, microplastics also act as tiny sponges that can transport chemical pollution through our oceans too. Microplastics are more difficult to remove from waterways than larger debris. Whats more, large pieces of plastic continue to break down into multiple, smaller microplastics as they age, making the problem worse. 

The increase since 2005 is likely due to an increase in demand for plastic goods combined with the degradation of macro plastics.