Erica: Microplastics can be found in every corner of our ecosystem. We find them in the air that we breathe, in our soil, in our tires, and the clothing that we wear, in our waterways and our oceans, and the food that we eat. We even find them in our own bodies. When staring down a challenge this complicated, how do we decide where to start? That's one of many things we're talking about in this episode of the podcast by the University of British Columbia Cluster for Microplastics, Health and the Environment. Join us for a conversation with Brian Hunt about his research with Herring in British Columbia's Denman Island, how microplastics can enter the food web, and why tackling microplastics requires a multidirectional approach. Brian also shares his story about how an obsession with fish and an opportunity to join an Antarctic voyage helped shape his career, and how he somewhat reluctantly joined the research effort to help tackle the microplastics problem. Take a listen.

Brian: I'm Brian Hunt. I'm an assistant professor at the Institute for Oceans and Fisheries and I'm an ecosystem oceanographer, which means I study how the ocean works, how the Pelagic Ocean works, which is the  open water part of our marine environment.

Erica: Wonderful. Thanks, Brian, and thanks so much for being here. Tell us how you became interested in this field.

Brian: Well, to tell you the truth, I was trying to avoid becoming involved in microplastics because I felt that I was very well subscribed already in my research and I felt that microplastics was a it's a huge topic and it was going to be it was going to require serious devotion to really become very familiar with it and to make an impact in that area. But I was approached by some community members from the Salish sea, the members of the Association for Denman Island Marine Stewards, and the Comox Nation, who were concerned about the potential effects of microplastics on herring in the area around Denman Island. So Baynes Sound in particular. And this is a key spawning area for herring. The Salish sea herring population is the healthiest population in British Columbia, but they've really concentrated all their spawning area now in this area around Denman Island, when they used to spawn more diversely across the Salish sea. So it's become an increasingly important area for them. And herring are important because they underpin the food webs on the coast, they are just really an essential organism, essential elements in the food web.

Erica: What is a food web? What does that mean?

Brian: The food web is all of the connected organisms in an ecosystem, and connected through consumption. So it's a network of animals that are feeding on each other, basically.

Erica: So is it like I mean, when we were in school, we would learn about a food chain, is a food web the same thing or is it different.

Brian: A food chain and a food web are similar. They referring to the same thing. They're referring to connection pathways between organisms through through consumption. So let's say phytoplankton are the base of the food web in the marine environment. And then they're consumed by zooplankton and the herring will eat the zooplankton and Chinook salmon will eat the herring. So that's a very simplified version. And it's a chain because it's one organism eating the other. But in reality, we have a web of animals out there. We have very diverse ecosystems and so are there multiple species that occupy any one trophic level or level in the food web. And so they interact in very diverse ways, and it makes this web of interactions, and that's why we call it a food web.

Erica: Okay. And so why are herring so critical to this one?

Brian: Herring are critical because they link the zooplankton, the small zooplankton, to higher level predators. So the herring are around I mean, they start off as tiny little eggs and larvae that are ten millimeters long. But when they're maturing growing up, they end up in the range of 20 to 30 centimeters in size. And so that's a good size for consumption by lots of different animals, there will be birds and seals and sea lions and bigger fish like salmon, humpback whales, will feed on on herring. And what the herring are doing is converting plankton into something that is edible by these bigger organisms. Those big organisms are not able to feed on the plankton because they're just too small. So they're the intermediaries. They make the plankton available to the rest of the food web.

Erica: Okay. And so where do microplastics fit in here?

Brian: So, let's come back to those herring population around Denman Island. So herring are plankton eaters, and they so they're swimming around and they're eating all the small particles in the ocean, and that really starts from their larval stages when they're really eating tiny things, to when they're growing up and the eating plankton that might be the size of a like a pea or a little bit bigger than that perhaps. And so they are engaging with the part of the food web that interacts with microplastics. So microplastics are these tiny little plastic particles that are less than five millimeters in size that are free drifting in the ocean. Well, they can be in the sediments as well, but for the herring we're interested in what's free drifting. And so either the zooplankton can be eating those plastics or the herring can be eating those plastics. And so it's a way for those plastics to enter the food web. And because there's so many animals that feed on herring, it becomes a pathway for plastics into the higher levels of the food chain. So up to those those big animals like Chinook salmon and whales and seabirds, etc.. So this is very important then to have a situation that herring are potential vectors for plastics transfer or transfer to the rest of the food web.

But before we even get into that point, plastics are important because of the potential effects that they have on herring. And so there was a particular concern raised around the area in Baynes Sound because of what's seen as a plastic problem with the shellfish industry. So there's a lot of shellfish farming there. There's a lot of plastic used in this industry. People observed plastic in that environment. There's cleanups, regular cleanups to to remove that plastic. And so there is concern that the plastic from the shellfish industry was entering the food chain getting into the water and then potentially a threat to herring. And this critical herring population that lives in this particular environment will spawn in this environment around Denman Island in Baynes Sound.

Erica: So when you say that the plastic is used in the farming shellfish, does that mean that it's in the equipment that is used in the farming in some way? What does that look like?

Brian: Yeah, there's well, in the shellfish industry, plastic is used for platforms for growing the shellfish that could be on the ropes from which the shellfish are suspended in the water. It's used in the transport of the shellfish and so the plastic that is, that is being used though it's large pieces of plastic. So this is not something that can actually be eaten by a hearing for instance, or a small organism. But the debris of this plastic was getting into the environment and then it can break down into smaller and smaller particles, which is what plastic tends to do. It gets smaller and smaller. And as it's getting smaller, it becomes accessible to other animals. So small animals can consume those plastics and that's how they can get into the food web.

Erica: Really interesting. Okay. Thank you. That's helpful visual. So could you walk us through in the work that you're doing with the herring, sort of the step by step of the way that you approach your research? What is the question that you start with to begin the process.

Brian: With this particular project our objective was to know how much plastic there was in the environments where the herring live. And particularly during the time when the young herring, the larval and juvenile herring, are growing up in this environment. So they use this environment for the very early life history. So for the first few months of their lives. And so we were interested in the in the plastic that was in this environment that they would be coming into contact with and then measuring whether that plastic was being consumed, either by the hearing directly or by the animals that they feed on, the zoo plankton. And that information helps us understand whether the plastic is actually reaching the herring and the next step would then be to figure out what the impact of that would be. But our purpose is really just to generate the baseline information of what's there, and is it reaching herring?

Erica: And how do you do that? What are the steps?

Brian: So to figure out what plastic is in the water, we use oceanographic techniques. So we collect water samples, and then we filter these water samples to remove all the small particles using very fine mesh filters. And then we also do net sampling to collect the zooplankton and larval herring. And we can then collect out particularly plankton species, individuals, and the larval herring stages. And we take all of these samples, the water, the zooplankton, and the herring larvae back to the lab. And then we basically have to dissolve away all of the organic matter that's in the sample. And what's left behind is hard particles, some of which are plastic and some of which are not plastic. At that stage we call them suspected microplastics. And then we have to investigate all of those particles to figure out whether they actually are plastic or not.

Erica: And so you mentioned that you were looking for the quantity of plastic in the water at a particular time of year. Is there a reason that there would be more plastic in the water at one time of the year than another?

Brian: The reason why we're looking at plastic concentrations at a particular time of year was that we were really focusing on the early life history of herring. And herring spawn in February/March, which is about the time of the spring phytoplankton bloom. That's an important time of the year. That's when the productive season in the ocean is starting. So the herring are you know, they're very strategic, and when they do their spawning - so they're laying the eggs so that the larvae are hatching at a good time to eat, to feed. And so we started something then, because we wanted to know how those larvae, when they're hatching out, how they're interacting with plastics. So how much plastic is there, how much they're ingesting, and and also to some extent what the probability of ingestion was. One of the things that was interesting from the study was realizing that, if you look at the ratio of microplastic particles to natural particles that the herring larvae eat, it's actually it's very low. There's there's a huge amount of natural material out there. So the chance of them actually eating a microplastic particle is, is pretty low, which was an interesting finding.

Erica: Any idea why?

Brian: Well, just because of the huge number of small plankton that are out there. So small phytoplankton, what we call microzooplankton, very small plankton particles, there's just so many of those compared to microplastics of the size that the local herring might be eating, that the chance of them encountering microplastics are very slim. So unless there's something about this microplastics that's very appealing to them, you know, that they see that maybe it's got a color or a shape or something that they like, which makes them select the microplastic as a food particle. We would expect that they wouldn't have many microplastics in their stomachs. And that's what we noticed, in fact, with the larval herring. Yeah. So there's an extension to this. So if you look at the size distribution of microplastics in the water, there's a huge array of sizes. And we didn't measure the whole size range, but we measured a good size range, I'd say. And what we notice is that as the plastics get bigger, the number of particles, natural particles, so plankton of the same size decreases as well. So the ratio gets closer to one, which means that you start having more microplastics relative to natural particles. And so this means that if you are something that's feeding on bigger particles, your chance of eating a microplastic is much higher than if you're a small larval herring. So that's very interesting because the young of the year herring, so the juvenile herring from the spawning in the February, and we sampled in September when they were about ten centimeters long, they had the highest concentration of microplastics in their stomachs. So there was a higher chance of them eating plastics, we could estimate that and this was demonstrated in what we actually saw in their stomachs. So the risk of microplastic consumption increased as the fish got larger, which was quite an interesting finding.

Erica: So what are some of the implications of that finding or what might they be?

Brian: Well, the implications of this are firstly that the risks are greater for larger fish, or at least the probability of consumption is higher for larger herring. And so if we're looking to understand the effects of plastic on herring, it might be more important to focus on these juvenile stages when they're eating more plastic than on the larval stages, which seem to have a very low risk of plastic consumption. And so if we were going to move to the next step of really trying to understand the effects of plastics, it would be good to concentrate on these juvenile stages rather than the larval stages.

Erica: Is that the next step in the study? What where do you go from here based on what you've built so far?

Brian: Good question. Well, the logical next step would be to do some experiments, I think, with plastics, to try and understand the potential effects of plastics on these juvenile herring. And one doesn't necessarily need to use juvenile herring as a model organism. One could use other animals in an experiment. But I think that this is really an important gap is - yes, we can detect the uptake of plastic into the stomach of of an animal. But the gap then is what does that actually mean? What does it mean for the health of the animal? And there's various bits of evidence out there that show either no or sometimes slightly negative effects. But I think that this needs to be done on an organism about organism basis. And it's quite challenging to do because I think one of the things that we've seen from experimental studies is that it's important to run them for quite a long time, not just have short term studies that are potentially not capturing the true effects of plastic consumption. And so this is something that's very difficult to do.

Erica: So can you say a little bit more about why running them for a long time is important?

Brian: I think that running the experiments of plastics for a long time is important because the effects might be slow, let's say chronic effects and slow to observe, slow to take effect. And so if we don't really run experiments for a long period of time, we could miss the significance of plastics to organism health. And so there's definitely a move, and certainly in some research groups, to run longer experiments, and experiments can be over a year in length to really enable us to understand chronic effects, which could be through the physical effects of eating plastics, but could also be through the chemical constituents of plastics, which by that I'm particularly thinking of toxins that might have long-term effects on organisms. 

So we got to the end of the study and we had identified two areas for next steps. One was trying to understand the effects of plastics on the fish themselves. And you could do this potentially with experimental studies. The other is to look at the effects of plastics or even the distribution of plastics that are smaller than microplastics. And so it becomes quite obvious when you're looking at the data that there is a lot going on and the smaller you go, the more microplastics you have. And the when you're getting below microplastics, you get into a size category we call nanoplastics. And these are extremely difficult to both sample and measure, probably more difficult to measure than actually collect. But these these particles are so small that it's difficult to isolate them from a sample and then to make the chemical measurements to determine that they are indeed microplastics is quite challenging. 

So I think an important area of research is to develop methods to understand the currents and distribution of nanoplastics, not just in the environment, but also in organs and tissues, because there is some interesting recent results showing the uptake of nanoplastics across the stomach into the organism tissues, so they can actually be found within the tissues. This is really important because it means that there's the potential for plastics to be transferred up the food webs, in tissues, and to bioaccumulate as well. So plastics are not just in the stomach, which is ultimately going to be egested, it's going to be passed through the intestine and and egested. And if the plastics are absorbed into the tissues, then they can be retained and they can accumulate over time. And that is a much bigger problem then than something that's just passing through the intestine. The nanoplastics everywhere - same with microplastics - they're in the atmosphere, they're in the soils, they're in freshwater and saltwater, and so atmospheric plastics can just be breathed in and get to your lungs and potentially be taken up that way. So it doesn't have to be just through the diet.

Erica: So when you say atmospheric plastics, what exactly does that mean?

Brian: That means small particles of plastics that are just floating around and being moved by the air, air movement. So we know this is a problem because when we are doing research on plastics, we have to be incredibly careful about contamination. And so we have methods to measure the plastics that are just in the environment. Wherever we're doing anything, whether we are something or in the lab processing samples, we have some some way to measure what's in the environment that could be contaminating our samples so that we can take that into account. This is very important. And so we know when we do this, so if we leave a Petri dish open on a benchtop in a lab and we look at it later, it has microplastics in it. And these could be coming from your clothing, someone else's clothing through the air ducts. There's lots of pathways for that.

Erica: So I mean, to recap, of course we all know that nano means very small, but microplastics are so tiny that they're in the air everywhere all the time? Are we breathing them in with every breath? Do we know?

Brian: Microplastics are around in the air and we are breathing them in. That's for sure. How many are we breathing in? I'm not sure. But they are there and they can be coming from many different sources. So just think of all the ways that we use plastic. So there's lots of big plastic structures everywhere. There's car tires, there's synthetic clothing. It's used in so many different ways. And so a lot of the plastics are large, but they all get degraded, break down over time and = become smaller and smaller. And they can then they become microplastics and they can become airborne just through the wind blowing. And so you know, one of the sources could be a landfill site that has a lot of plastic in it. And, you know, that is that is degrading over time. And that dust that is blown off that landfill site will have plastic in it. But it doesn't have to be a landfill site. There is plastic all over the place. So there are lots of sources.

Erica: There are lots of sources and many points of entry, it sounds like, into the way that we talk about where microplastics exist in our ecosystem. How do you figure out where to start?

Brian: So I think we are interested in the, at the largest scale, we are interested in the lifecycle of plastic. And so that means knowing where we introduce it to the system, and the system could be anything. It could be our city, it could be farming, it could be it could be anywhere. But it could also be how we introduce it to a natural system. And so you know, how it might get into a forested area that is for all intents and purposes, untouched by humans. And the starting point is to first you know the entry point. So where are we using plastic? And then to understand the movement of that plastic sideways and vertically through the environment. And so to do that effectively, it's quite clear now that we need to be taking into accounts what's in the atmosphere, what's in the waterways, what's in the soils and and what is in the ocean.

And what's important for me as a marine biologist is to know, firstly, what are the sources? So where's all this plastic coming from? And then how it is.. I'm immediately interested in how it affects the living things and the living, breathing ecosystems that we depend on. And then beyond that, where does it end up finally? What are the places where it actually accumulates?

Erica: Really interesting. Brian, I wonder if I could ask you to take as wide a lens as possible on your own work and tell us the story of how you became interested in marine biology. How has your research program evolved over time?

Brian: Hmm. Um, I, I wouldn't say that I was. So I mean, let's, I never, I never considered myself to be a marine biologist, but, um, I guess that's what I am in some ways. Well I study biology in the ocean. But I would say that from my earliest recollection, this was just something that I did. I was interested in biology in the ocean. Whether it was fish or plankton or seaweeds or rocky shores or estuaries or whatever it might be. The truth is that I'm fascinated by everything in our, in our environments, so all ecosystems are equally fascinating, but I never wanted to get into a career of marine biology. That wasn't my goal I would say. Of all the things that exist in the natural world, I suppose I was most fascinated by fish and I would say almost obsessed with fish. And so my goal was to study fish. So the reason why I got into marine biology, and I distinctly remember telling people that I would never be a marine biologist, was that someone offered me an opportunity to go to Antarctica when I had finished my undergrad degree as a research technician on a research voyage, oceanography voyage. And I thought, well, I'd never dreamed I'd go to the Antarctic, but this is an opportunity I can't pass up. So I went and I did that. And then I just totally loved this experience of doing research on the ocean. And so that totally changed my career path, I would say.

And so now I do I do work in the Pelagic Ocean. I say that I do that, but I'm very interested in much more than that. I'm interested in the connection between systems. And so I think that that maybe the overarching, overarching thing for me is that I really feel strongly bound to all ecosystems on earth. And I am fascinated by the connections between them also. So whether that is the atmosphere, land, freshwater, or oceans. I just happen to be working in the oceans. But I'm always looking to the land. I'm looking to the water, the fresh water. I'm looking to the atmosphere and how it connects with my marine systems that I'm so fond of and how it impacts them and how they feed back to each other, their positive and negative feedbacks.

And part of that system is humans. And and so that's, that's part of what I research, is this human interaction with all of these different ecosystems and how they work, trying to figure out how they work so that we can do our best to sustain them and perhaps get them back to a healthier state.

Erica: Really interesting. It strikes me that you're talking about this vast, not just in a systems level approach, but in a multi systems level approach and finding the points of connection between all of these things. But then at the same time you're able to look at it in the context of something as specific as herring. How do you navigate the complexity of the vast system that you're looking at and how do you identify these specific points of connection to investigate?

Brian: Well, it's helpful when you're trying to navigate a complex system, it's helpful to just have a starting points. And the starting point doesn't have to be the beginning or the end. It can be it's just a, it's a node in a network and so herring is that. Herring is a node in a network that is, firstly it's a food web. But secondly, and beyond that, it's an ecosystem. And the difference between the food web and the ecosystem is that with the food web we're just thinking about organism connections in terms of who eats whom. And from the ecosystem perspective, we're thinking about all of the non-biological factors that are affecting the food web, whether it's the nutrients that are available for plant growth or temperature effects or freshwater effects or you know, might be fishing effects on the food web, on the ecosystem. So there are these different layers. And so coming back to this question about how to navigate complex systems, I do find that it's very helpful to have a starting point, a node in the web and to work out from there and identify connections. And if you as you work outwards from any one node, you can identify all of the connections in the end.

Erica: And so since the beginning of the UBC Microplastics Cluster, you've worked with academics in the field, who are in a number of different fields, and are all members of this research group. What do you see as some of the sort of existing benefits or potential benefits of working with academics across disciplines?

Brian: The UBC Microplastics Cluster in particular is a very interesting collection of people because they cover such a broad array of disciplines and they are experts in their disciplines. They really are world leaders in their disciplines. And so it's quite an exciting group of people and enables us to tackle almost all aspects of the microplastic problem at a very high level.

And I think the cluster itself is very exciting because of the potential to, to really work away from one's area of expertise and to connect with people that are doing things in quite different ways. And so to really have a holistic approach really to microplastic problem. So taking it from, you know, the production phase, looking at the lifecycle of plastics, you know taking it from the production phase all the way through to the movement of plastic through the system, identifying sources in the environment, identifying effects on organisms, including people, and then also thinking about solutions for, you know, how we can optimize our systems to minimize these inputs, plastic inputs to the environment.

I think with the microplastics cluster, our intention is to really understand the lifecycle of plastic and the ecosystem effects and potential solutions to the plastic problem. I think that it would be really wonderful if this is seen as, that plastic is seen as almost a sentinel in a way of a much bigger problem than just plastic. There's a lot of other human impacts in the ocean, in the land, in the atmosphere. There are other pollutants, there's you know, there's climate change. There's various other things that are going on that are extremely important. And I think that if we use the sort of integrated approach to studying the plastic problem, it would be ideal if that can be applied more broadly to other problems as well.

So we need to keep in mind, we need to remember, that the plastic problem does not occur in isolation and that we need to be linking it back to other human induced pressures on our systems because again, it comes back to integrated effects. So it could be, and will be, the case that you know, the plastic problem will be mediated by other stresses on the environment.

Erica: So what do you think is the key to studying problems that are this vast and involve this many different layers and stressors and considerations? What kind of approach is needed, from a collaborative perspective, to drive the research forward and take the research out of the universities and drive better policies and practices.

Brian: It's a good question. So I think the the microplastic problem is one that could seem maybe overwhelming because it has such vast scales. But I don't think that we should think about not being able to to deal with this. I think we we have to approach it from different directions and it requires all levels of action. So it requires academic research for sure. And that can be from local to global scales. And that could be research on effects at a local scale to research on distributions at a global scale. And research into policies that can be developed to reduce the production and use of plastic, and measures to limit their introduction to the environment.

So there are these many different scales. But I think that it absolutely needs to go beyond just research. And obviously policy does that to a large extent because just by the nature of of what it is. But we also need to engage with people outside of academia, in industry, NGOs, and members of the public. So doing so on different scales because I think everything we do makes a difference. And so it could be just you know, reaching people to educate on plastic use in the home. That makes a difference. As well as working with industry to have different sort of manufacturing processes that decrease plastic production, or whether it's, you know, waste management, like how we deal with waste and and limit the introduction of plastic to our system. So definitely we need a multi scaler approach that is, both in space and also with the, basically stakeholders that we would be engaging with.

Erica: And what does it mean to be doing this work in British Columbia in particular?

Brian: I feel that British Columbia is a place where.. we have an amazing, beautiful natural environment here. And I feel as though we, there's a lot of passionate people here, about the environment. So people who really care about the environmental health. And so it's a place where you can, there can really be action. There are people across all sectors of society who are interested and looking after this place. And so that makes it an exciting place to work for that reason because it feels like change is actually possible. So in B.C., I would say that, you know, we have the potential to be leaders in solutions to problems. From a research perspective, I think in British Columbia, we have an opportunity to research the effects of plastics on, I would say, model systems, a lot of model systems. You know, that could be, we talked a lot about we talked a lot about herring. And herring, the pelagic food web and the role of herring as something that's very important. And it's a model system that can be where information gained from their system is applicable to many other parts of the world as well. So I suppose in some ways when we're thinking about the work that we do is important to try and put it in a context that makes it suitable or relevant to people in other parts of the world. And, you know, we do want to have impact with our research. We do want it to be meaningful. And so sometimes that means not thinking about particular species, but more about, you know, the functional role of an animal, for instance, in a system. Or a particular ecosystem type, rather than just being very specific with a place or a particular species.

One of the benefits, one of the many benefits, of working in British Columbia is that we have people across all sectors who are very passionate about their environments. Which means that it's possible to engage you know, from our, we work out from a research perspective to, we can engage with people who are trying to find solutions in the ocean that, maybe they're doing restoration projects. We can engage with people in industry who are interested in doing things in a different way, a more environmentally friendly way. We can engage with policymakers who are like minded. So, yeah, I think it's a system where we can try some models on for size, some models of doing things and then be world leaders in that sense of finding better ways to to do things, to have sustainable systems.

Thank you for listening to the podcast of the University of British Columbia Cluster for Microplastics, Health and the Environment. This cluster brings together an interdisciplinary group of scholars aiming to support the development of informed policies regarding plastics pollution. UBC is situated on the traditional, ancestral, and unceded territory of the Musqueam First Nation on the Point Grey Campus and the Syilx Peoples on the Okanagan Campus. 

This episode was produced for the UBC cluster for Microplastics Health and the Environment by Hikma Strategies. I'm your host, Erika Machulak, working with Creative Director Sophia van Hees. This episode includes original music composed by Matthew Tomkinson, the 2022 Hikma Artist in Residence. This score interweaves musical notes and the crunching and clicking of plastic to evoke the omnipresence of microplastics throughout our ecosystem. Matthew holds a Ph.D. in Theatre Studies from the University of British Columbia.