From Microplastics to Macro Solutions: Unveiling the Ocean’s Plastic Paradox with Dr. Kara Lavender Law

Dr. Law, thanks for taking the time to meet with us. Would you like to introduce yourself?  

Yes, of course! Thanks for having me! My name is Kara Lavender Law, and I am a research professor of Oceanography at the Sea Education Association or SEA, a small nonprofit organization. We are located in Woods Hole, MA, on Cape Cod. I'm talking to you from my home in Maine, about a 3 1/2 hour drive along the coast from Woods Hole, MA, where I've worked remotely for long before the rest of the world worked remotely. I've been working remotely for about 14 years, since my first child was born, so I do not get out to sea anymore like I used to. My background is in ocean physics, which I studied for my Ph.D. and in my early oceanography research. Before my career shifted to plastics, I studied deep ocean currents and how seawater transports heat, salt, and freshwater. And so this lends itself to thinking about how the ocean also transports pollutants and particles like plastics.  

What do you do at SEA? 

At SEA, our primary mission is to educate undergraduate and high school students. The students are mainly from the US, but some international students come to our campus on Woods Hole, too, and take coursework to prepare to sail on one of our two ships. They are sailboats, but they are also research vessels. The ship's mission is to get from one port to another and collect data to support undergraduate research projects. Since the 1970s, we have been towing plankton nets at the sea surface to collect organisms like plankton and large macroalgae. But we've also collected tiny bits of plastic. So, in the mid-1980s, we had a scientist named Jude Wilber who tasked a student to study the plastics coming up in the plankton net. That began a decades-long time series measuring microplastics floating at the sea surface in the western North Atlantic, Caribbean, and North and South Pacific Oceans. We've had a few cruises that have crossed the Atlantic just into the Mediterranean, but most of our data are from the western North Atlantic and the eastern Pacific Oceans. 

Our students have been collecting these data for decades. For several years I taught students in the classroom and on the ships, and oversaw their research projects. And then, around the mid-2000s, we started hearing about the Great Pacific Garbage Patch and floating islands of trash and this horrifying problem of flip-flops and bottles piling up in the ocean and causing all kinds of issues. However, we realized in our organization that people needed to visualize the situation as it is in the sea. They weren't really talking about the tiny bits of plastic.  

My background in ocean physics was helpful because I could investigate these enormous accumulations of tiny floating microplastics in what are the actual garbage patches. They're not giant floating islands but a dispersed mixture of tiny plastic particles. 

That was how I got into the plastics business, with that first paper, which was published in 2010. It's a while ago now, and I've had a lot of incredible opportunities that have taken me in many different directions. I still do ocean research, and I do research mainly trying to understand how plastic gets into the ocean and how it moves and changes and breaks apart. But I also feel passionate about solving the problem and using science and evidence to inform reasonable solutions. And that‘s how I‘ve ended up at the meetings with your colleagues from MIX-UP working very far away from the ocean, thinking about the materials we use and what we do with them at the end of their lives. I am very fortunate to end up in that community of people who really can change how we think about materials, how we use them, what we put in them, and what we do with them when we‘re done with them. And so I‘ve learned a lot and helped inform the community way upstream about what it looks like in the environment, and the kinds of problems we must worry about. 

How do ocean currents affect where plastic ends up? And how could this knowledge help us to mitigate this issue? 

It's a fascinating question about ocean currents carrying plastics because you can think of this in many frames. You can think of this as a question about putting these contaminants in the ocean: We know they can cause harm if animals encounter them, whether it's substantial items like fishing nets or tiny things like microplastics. If you want to understand where the harm lies or where the riskiest parts of the ocean are, you need to know where the plastic is. And how plastic is transported depends on many factors, not just the plastic but also the ocean. If you have a big fishing buoy at the sea surface that sits relatively high, it will experience movement by the wind and ocean currents. The wind is more important in determining how it gets blown around. Some plastics will actually sink, and they will likely not be transported nearly as far in the ocean. But they might affect the deep ocean or seafloor communities.  

One crucial piece is that we know that when plastics are exposed to sunlight in the presence of oxygen, chemical changes occur that weaken the material and cause it to break apart into smaller pieces. So, that's another factor in understanding marine litter and the environment: How long has it been out and exposed to sunlight? That question will also play a role in trying to understand where the plastic goes. 

From an oceanographer's point of view, some of my work has taken the flip side because these tiny plastics can't move on their own, and they're only being moved by ocean currents. So, now we can learn about ocean currents by looking at the plastics' locations. You know, if you imagine that you put some dye on the ocean surface, you could watch it drift around. Similarly, plastics can help us understand finer-scale aspects of ocean circulation. 

You just talked about sunlight and degradation. What can you tell me about the long-term implications of plastic degradation in our oceans? 

This is a big question. It's well understood, especially by people who make these materials, how the plastics chemically degrade mainly at the surface when they are out in sunlight. If you make an outdoor chair, you must know how long it will last and what will happen to the material over time. There are fewer types of applications for ocean use of plastic. So there has been less work into understanding what happens if you put plastic into salt water, but we've been doing some of those experiments, and lots of other people have as well. We have some hypotheses about how sunlight drives these chemical reactions, but there are still questions about how the plastics fragment. It's not that it breaks in half, and then the two halves break in half again. It's not so orderly as that.  

But research about this matters especially for the organisms that encounter the plastic because if you have a tiny plankton that's microscopic in size, it probably doesn't care very much if it comes across a floating plastic bottle because while it may run into it, it's not going to eat it, right? However, if you have these smaller and smaller particles of plastic, then the smaller animals at the base of the food web can eat those plastics, and there might be detrimental effects on those organisms. And the smaller the plastic, the more accessible it is. The more accessible to a broader range of organisms, and the riskier it is once consumed because we think the smallest particles can move between tissues in the body. So, everything I've just described has a lot of uncertainty around it. 

Does that mean that one of the big questions is: How long will this stuff stay in the ocean? 

Let's imagine plastic could just drift around in the ocean forever. 

Would it be decades?  

Would it be centuries?  

Would it be millennia?  

You can find all kinds of statements about it: "Plastics will last forever!" and "Plastics will last a thousand years!". None of that has been substantiated. We don't actually know. So, one of the biggest questions right now is how small do the particles get. And if they get small enough, might microorganisms be able to remove them and remineralize the plastic so it's gone or undetectable? And that's a big question mark. We are still determining the answer to that. But you can see how if you continue putting plastic in the ocean, this becomes a crucial question because we need to know how long those effects would continue, even if we were to stop today. 

Many people are already aware of the Great Garbage Patches. However, the dangers of microplastics might be even more significant because everything ends up as microplastics one day. Though, microplastics seem harder to grasp because we can't see them. How do you, as an educator, talk about this big issue? 

It's a communications challenge. When we published our data in the early days, we had many requests for photos of what it looked like out in the open ocean. If I showed pictures of what it looks like, it just seems like the ocean. On a flat, calm day from the ship's deck, you could notice what looks like confetti. But that is not really impressive from a shock-and-awe perspective. This is why even though we have known about microplastics since the 1970s, there was only considerable concern, public or scientific interest, in this problem once there was this notion of the floating island. That speaks to the importance of science communication and the dangers of science communication. I don't know if I'd still be doing this work if we didn't have those images almost 20 years ago because they spurred a lot of work. 

But at the same time, it's so important to talk about the real problem, not the shocking depiction of the problem. One of the best things we can do is get people out on ships. Because when you tow a net in certain parts of the ocean, and most of the time you pull it, it's full of brown and clear goopy stuff or maybe some fascinating animals that you would otherwise only see in an aquarium. And then we see plastic mixed in with that. That is shocking. You are disgusted that 1000 kilometers, 2000 kilometers from land, you're finding these tiny bits of plastic mixed in with marine life. They don't belong there. 

As the average person on land, you are used to seeing litter all over the streets. Even if you don't live in a very polluted area, we all look past the candy wrapper or the straw on the street. So it's a challenging problem. 

One of the things that has gotten people's attention much more recently is that we're now looking for and finding tiny plastic particles in the human body. And so that brings it much closer to home. It's not just a trash problem. It's not just an ocean problem. It's actually potentially a human health problem. 

Are there any misconceptions about biodegradable plastics that our readers and the general public should know? 

Yes, there are only misconceptions about biodegradable plastics. Unfortunately, the word biodegradable has been misused or misunderstood, whether intentional or not. The way that I like to talk about that is to start with the term "bio." "Bio" is used both in talking about the material the plastic is made of and what happens to it at the end of its life. So, we must be cautious to separate materials made from bio-renewable resources from those that will break down or mineralize into basic building blocks in the environment. 

You can make biodegradable materials out of fossil fuels, and nonbiodegradable materials out of corn. That's why we must be very clear about what we discuss when discussing biodegradables. 

Biodegradability is a property of a material, which means able to break down into its fundamental components in a particular environment defined by the temperature, the humidity, the oxygen content, and the pH, for example. Many physical factors have to be in place with the right community of microorganisms for that material to be fully broken down and mineralized. 

When we talk about products on the marketplace, really we're talking about compostable materials, which means for them to break down, they need to be in a commercial composting facility, not tossed out the car window or even put into a backyard compost bin. So testing and labeling is going to be incredibly, incredibly important. 

Could you share your experiences on what big organizations are doing to address plastic pollution and why – if so – progress might be slow? 

I have been involved with UNEP over the years because they have long focused on marine debris and ocean plastic. After working on the problem of ocean plastic pollution for so long, it impresses me that we are at a point where international negotiations are happening. It is a sign of progress and serious attention to this plastic problem in the environment and the sustainable use of plastics, which we all rely upon. But it is challenging, because even if we agree to make less plastic, or not make more, which plastics are we talking about? Which applications are we talking about? And is that the same in a developed nation versus a developing country or one geography in the tropics versus another near the poles? Everybody has a different framework and set of immediate problems to address. Global issues like plastic pollution are challenging, but it feels like we are starting to make progress.  

What are the critical challenges in bridging the gap between scientific understanding and policy implementation? 

There are so many open scientific questions that, as a scientist, I am inherently interested in answering. Still, some must be answered thoroughly to inform good policy. Understanding the fate of plastics in the environment is essential because if they're not around for a million years, that is important to know. And understanding the risks and health effects of plastics use is really important to know in order to make evidence-based policy. We need to have a scientific approach to evaluating policy decisions. We can come up with different interventions. One example is a container deposit. Where I live, we have container deposit laws. So when you buy a beverage bottle, you pay an extra 5 or 10 or 15 cents, and when you return the bottle, you get your deposit back. There is evidence of higher bottle collection rates for recycling in places with this policy. That's a great example of how information and data on bottle collection and recycling rates can help implement a policy. A crucial step is the willingness to adjust if the expected result doesn't occur. We may think, "We must do anything and everything we can! It doesn't matter if it works or not! Throw everything at it!" I understand that notion of urgency. But, if we want to use our resources efficiently, we need actually put the scientific approach around these actions to say, is it making a difference? Is this a path we should continue following? 

Thank you, Dr. Law, for these great insights and opinions! 

In wrapping up this dialogue with Dr. Kara Lavender Law, we are left with a more profound understanding of plastic pollution's complications and the pivotal role of scientific research in influencing effective and informed policy implementation. The challenges are undeniably vast, spanning across diverse geographies, economies, and perspectives, yet the push towards a sustainable, biotechnological conversion of mixed plastics into valuable bioplastic showcases a beacon of hope and innovation in addressing one of the most pressing global issues of our time. As Dr. Law underscores, a scientific approach, international collaboration, and the flexibility to adapt strategies based on real-time outcomes are critical in navigating this complex path.  

The MIX-UP project stands at the forefront of this transformation, embracing the vision of converting plastic waste to plastic value and championing the establishment of a sustainable, eco-friendly cycle for plastic production and utilization. The journey may be long and arduous, but the combined forces of scientific insight, innovative solutions, and global unity forge a robust pathway toward a cleaner, healthier, and more sustainable world.