To Stabilize Microplastics, Even a 1% Reduction Matters

The power of small steps towards a cleaner, healthier planet

This wasn’t the snorkeling day we had envisioned.

We were in Colombia when we I decided to enjoy the underwater beauty in the Caribbean. I usually schedule a scuba-diving trip, but I wanted her to join, and an ear injury prevented her from going too deep yet.

Now, before anyone enquires, I am a conservation ecologist. Thus, I know the best practices for minimizing the impact on the ecosystems. For example, I never wear flippers when swimming in shallow waters and don’t use sunscreen (I put on protective clothing instead).

Initially, we thought we would have a relaxing time floating over the reef and enjoying the views, but that wasn’t how it ended up going. Despite being in a National Park dedicated to scientific research, trash was everywhere—plastic trash, specifically. So, what did we do? We did the same thing we do when we encounter trash on a trail. Together with our peers, we took on the monumental task of picking up every piece of trash we could encounter and filling bags upon bags. Not bad for a family workstation.

In recent years, the issue of plastic pollution has gained public attention, with microplastics—tiny plastic particles less than 5 mm in length—emerging as a threat to marine life and, eventually, human health. But a groundbreaking study led by Dr. Zhenna Azimrayat Andrews from Imperial College London, in collaboration with researchers from GNS Science, has shed new light on the issue. Luckily, its findings come with some good news: They reveal that even modest reductions in plastic pollution can significantly stabilize the levels of microplastics in our oceans.

Microplastics can now be found in every corner of the Earth’s oceans, from the surface to the depths, and even in the most remote areas far from human habitation. These particles can be found in marine organisms and, alarmingly, in the seafood on our plates. Yes, in our food. “Plastic is now everywhere in the environment, and the ocean is no exception,” says Andrews. “While our results show that microplastics will be around in the oceans past the end of the century, stabilizing their levels is the first step towards elimination.”

The study, published in Environmental Research Letters, explores the impact of various hypothetical plastic pollution reduction scenarios on ocean microplastics from 2026 to 2100. Andrews and her team developed a sophisticated model to predict how different levels of pollution reduction, i.e., how much effort we put into reducing plastic pollution, would affect the concentration of microplastics in the ocean. They examined eight scenarios, ranging from a 1% to 100% annual reduction in plastic pollution worldwide.

Biological aggregation is one of the primary “natural” mechanisms by which microplastics are removed from the ocean’s surface. Microplastics often clump together with organic materials, such as plankton, marine snow, and fecal pellets. These aggregates can sink to deeper ocean layers, effectively removing microplastics from the surface waters where, since most marine organisms feed on plankton, they pose the greatest threat to marine life.

However, things are not as easy as it sounds. The study highlights an important challenge: microplastics are buoyant, which often prevents these clumps from sinking, trapping them near the surface. This important feature highlights the complexity of addressing microplastic pollution.

Even if we reduce the annual production of plastic pollution, microplastics can persist on the ocean surface for centuries, as the process of biological aggregation can be incredibly slow, necessitating that plastic breaks down first. “As marine life holds onto microplastics near the surface, even if the level of pollution produced yearly is reduced, there would still be microplastics in the surface ocean for centuries,” says Andrews.

The researchers conducted this study using the University of Victoria Earth System Climate Model (UVic ESCM), which includes representations of oceanic and biological processes. Based on historical data and projected future emissions, they simulated the scenario that led to the introduction of microplastics into the ocean based on records from 1950 to 2026 (past events).

Then, they completed the model to simulate scenarios from 2026 to 2100 (potential future scenarios). They applied eight different pollution reduction trajectories to see how these scenarios would affect microplastic concentrations.

The model considered how microplastics interact with the ocean’s biological components. For example, microplastics can be ingested by zooplankton and other small marine organisms, incorporated into fecal pellets, and then sink to the ocean floor. However, the buoyancy of many microplastics means that these fecal pellets often remain suspended in the water column. There, they are eaten by other organisms, continually cycling between the surface and deeper layers.

The study’s comprehensive approach allowed the researchers to explore the immediate effects of pollution reduction as well as the long-term implications for ocean health.

Researchers considered this and many other phenomena that could either facilitate or make microplastic removal over time difficult. Thus, by considering all these complex interactions between microplastics and marine biology, the model provides a more realistic picture of how and whether microplastic levels might change over the next century.

However, despite the complexity of the problem, the study offers a hopeful message: small steps can make a big difference. Reducing plastic pollution by even a small percentage each year can significantly impact the levels of microplastics in the ocean. This finding is crucial for policymakers and environmental organizations seeking effective strategies to combat plastic pollution. It is easier to tell governments that “any” change could make a difference. We need to strive for “better,” not “perfect.”

Additionally, the researchers emphasize that coordinated international efforts are necessary to achieve these reductions. While individual actions are important, systemic changes at the industrial level will have the most significant impact. “We need a more sustainable lifestyle integration, rather than people having to make individual choices,” says Andrews. This approach can help relieve the burden on individuals and organizations, allowing for more substantial and lasting changes.

These bigger efforts could include banning certain disposable or single-use plastic products, for example, which have proven effective in some countries.

The study shows that, ideally, countries need to reduce plastic pollution by at least 5% each year to stabilize microplastic levels. That said, it is important to understand that while this minimum threshold is crucial, even a 20% reduction in annual plastic pollution would not significantly diminish the existing levels of microplastics.

So, a 5% reduction would only keep it stable while preventing it from further increases, allowing the ocean to begin a slow recovery process. Dr. Andrews explains that, that said, “the current global output of plastic pollution is so great that even a 1% annual reduction in pollution would make a big difference overall.”

So, in other words, even if small, we shouldn’t underestimate the power of any reduction in plastic production. Even if imperfect, every step in the right direction could have a significant impact and help the oceans run their own mechanisms.

As the world tries to understand plastic pollution, this study provides valuable insights into how, little by little, we can make meaningful progress. By setting ambitious yet realistic targets and aiming for global cooperation, we can begin to curb the tide of microplastics in our oceans. Andrews and her team hope their findings will inform upcoming UN negotiations and help shape effective policies for reducing plastic pollution.

We know what you may think: completely eliminating microplastics from our oceans may be unrealistic in the short term. And I agree. However, stabilizing their levels and preventing further contamination is something we can aim for. We can work towards a cleaner, healthier ocean for future generations by taking small but steady steps. As Dr. Andrews puts it, “stabilizing their levels is the first step towards elimination.”

I firmly believe that we should be capable of embracing this challenge and taking those crucial steps toward protecting our oceans and the life they sustain. In the meantime, I will remember to carry a bag with me every time I visit the ocean, just like I do when I go hiking. We have one stunningly beautiful planet, and it’s our duty to take care of it.