Dr. Denise Hardesty is a principal researcher at CSIRO Oceans & Atmosphere in Hobart, Tasmania. She’s done extensive research over the years on marine plastic debris by studying sea birds, sea turtles, and waste reduction campaigns.
We discuss what happens when certain marine animals digest plastic, whether it’s safe for us to eat seafood that contains plastic, and what it’s like to be a distinguished scientist in the field of marine debris research.
TRANSCRIPT
Laura (31s): Hello everyone. And welcome to the ZWC! Today we’re speaking with Dr. Denise Hardesty. She’s a principal research scientist at CSIRO ocean and atmosphere in Hobart Tasmania. Denise, welcome to the show and thank you so much for joining us.
Denise (45s): It’s a pleasure to be here. Thank you.
Laura (50s): Let’s talk about science because you’ve done some pretty amazing research projects, all about plastic years and years of it. It seems so I think this is going to be a really cool episode. So can you give us some background on your toxicity study on birds ingesting plastic? And I know there was some good news and some bad news, so maybe you could kind of give us both from that study. So we’ve done a whole suite of studies on seabirds and other Marine wildlife, and the impacts of plastic, everything from how much do they eat, what birds eat, what to, what are the potential toxic dialogical impacts on birds?
Denise (1m 36s): And so what we did in that particular study with a toxicology study was to use a model species. So we used quail as a proxy for seabirds, cause we can’t go out there and actually feed plastic to seabirds in the way that you can and rear them. And, you know, so basically raise them from egg to adult and then to the next generation. And so what we did is we actually fed birds plastic and we fed them basically ground up little plastic pellets.
Denise (2m 7s): And what we found are a couple of things. So what we didn’t find. So the good news is we didn’t find really long lasting toxicological effects on adult body, weight or plastic killing the birds per se or things like that. However, what we did find is a higher frequency or more cysts in male reproductive organs. And we also found that there were some delays in how quickly chicks grew through to sexual maturity overall. Denise (2m 38s): However, we did not find a change in survival ship or reproductive output. So we looked at birds that were fed plastic and then their offspring and then their offspring’s offspring, so that we could really look at that. And I think the thing that’s really interesting about this is that we hear so much in the media today about plastic kills, plastic kills, plastic kills, and sometimes plastic kills. Yes, that is true. However, it doesn’t always kill and actually really understanding some of those mortality effects.
Denise (3m 11s): And then some of those sub lethal effects is really important to understanding the potential flow on effects of plastic in animals, diets, whether those animals are birds or Marine mammals or even humans. Laura (3m 28s): So I guess when the, the whales are dying, cause we know the whales are dying directly. I would assume that maybe it’s the same with birds is that they’re just getting the pieces maybe lodged in their digestive system.
Denise (3m 40s): Yeah. So obstruction is the number one reason that plastic kills wildlife from what we have seen. And the other thing to remember is because you find an animal that is full of plastic doesn’t mean that the plastic actually killed it. It doesn’t mean that the plastic didn’t kill it, but there are very specific, you know, ways that we need to look to actually assign cause of death due to plastic. So yeah, there could be a whale with its stomach full of plastic that doesn’t necessarily mean that the plastic killed the whale.
Denise (4m 15s): Right. You have to really see, is there an obstruction? Is there a gut perforation? Is there something that you can say that actually really costs that death? Now there’s a, and that’s because, you know, in science geek speak, there’s a real difference between causality did a Cosby or correlation is a associated with B. Do we find that birds that have more plastic in their guts weigh less? Well, yeah, you, you probably tend to, right, because if a bird or if you know, a whale or another animal eats plastic, it’s going to displace food.
Denise (4m 54s): And it may actually result in the animal feeling fuller, which means that they won’t feed, which means that they will lose weight. And they obviously aren’t getting nutritional value from having eaten plastic. So there are all sorts of effects from it, but that doesn’t necessarily mean that the plastic has killed the animal. If you find that it is dead and that it has eaten plastic, does that make sense?
Laura (5m 18s): Absolutely. And that’s very fitting for 2020 to think about that. Maybe even if something washes up with a belly full of plastic, that maybe it didn’t die that way because of a COVID because I think we hear sometimes that if someone dies of something, but they have COVID, then they can be marked down as a COVID death. So I guess it’s a, it’s kind of similar to finding something
Denise (5m 42s): COVID related effects. So, you know, one of the things that we find each year, birds that fledge from the nest, they go out into the environment and they’re pretty young, naive, inexperienced consumers. So, you know, do younger birds eat more plastic and they eat more plastic, you know, do they have lower fitness? Are they less able to fly or they’re not going to be as good at migrating? Are they already naive juvenile young birds? Are they getting out there? You know, and then not making it, you know, most birds don’t make it when they fled from the nest, right. Denise (6m 14s): To have stable populations of birds, we need for adults to replace themselves. Right. And so FSC bird, like an albatross has a lifespan. If it lives for 80 years, really for the, for the population to remain stable, you need to just replace yourself once. Right? We know that from human population, if we have an increase in human population, it means that we’re having more than zero replacement value. We are having more babies than, you know, on average than just replacing ourselves and those living to adulthood.
Denise (6m 48s): Right? So I think, you know, it’s really thinking about the lifespan of the animal. If birds are breeding every year or every two or three years, even, but they have 30 years that they can reproduce, you know, how many of those chicks are actually going to make it to adulthood? You know, there’s a lot of risks out there in the world, right? You can be caught as bycatch and you know, from fishing, which doesn’t happen very often because we have better fisheries management, you can eat plastic, you can be eaten by something else.
Denise (7m 22s): You can be, you know, affected by disease. You can not find food. So you can starve to death. You can be blown off course by major storms. You know, there’s a whole bunch of things out there in the big oceanic world that make it hard to eat out. You’re living there.
Laura (7m 41s): So what you’re saying with the bird population and replacing itself, something I wanted to ask you is if you think that our problems with fish docks are like worse than our problem with plastic in the ocean,
Denise (7m 54s): Well, it sorta depends upon who you are and what you value and what’s important to you, right? I mean, what we know is that global fish stocks are decreasing. We’re seeing an increased demand from humans for fish. We see an increase in illegal fishing. In some areas. We know that there are many, many threats and many risks, right? Fish reproduce with large numbers over short periods of time, you know, and that’s really important.
Denise (8m 25s): And it’s really important also for global food security, right? As we have increasing populations, as we have increased focus and reliance on protein from our global fish stocks, it’s really important that we have sustainable fishery fishing practices and that we maintain and support those sustainable fishing practices, I would say.
Laura (8m 49s): Yeah, yeah. We had someone come on the show recently and say that fish farms are the way to go. And then you, I’m sure you’ve heard of Suzuki, right? Yes. In Canada. Yeah. So he’s, he’s kind of been telling us for years that farmed fish is bad because it can, it can lead to diseases in the ocean to wild salmon and, and stuff. So, so I think a lot of us are like, not really sure what to do
Denise (9m 11s): Well. Yeah. I mean, so it is really interesting and, you know, fish farming also you, because of so much waste, you know, from the concentration of fish, in those areas, you can also get, you know, eutrophication in the areas. You have other issues in areas where you have fish farms often. So, you know, I think it’s really figuring out what’s the best thing to do and where do we do it? Right. If you actually were having fish farms out far off shore, where you have lots of currents and flow and things like that, you would potentially wreak havoc on the environment, but we don’t put our fish farms out in those areas generally because it’s very expensive and time consuming and risky because of storms, right.
Denise (10m 4s): That can, you know, that can blow out the anchors for keeping the pens in place. Right. And so then you would just be ending up with Marine debris. If you have your fish pens out in open ocean environments, often, you know, where they get blown out, where they, you know, where they don’t last. And again, it’s, it’s more time consuming. It’s more expensive, it’s more risky to get there. So we ended up having them in our coastal areas. So, you know, I think you’re right though. There’s so much information that comes at us as consumers, but it’s hard to know how to make the best decision.
Denise (10m 39s): I think sometimes, which is really, I think the point that you’re making, like we’re told to do this, we’re told to do that. What’s the best thing to do, you know? And it becomes tricky in such an information rich age in one, we’re hearing so many different perspectives and points of view on what’s good and bad and otherwise.
Laura (10m 57s): Yeah, totally. Yeah. I decided to give up like all fish for a while and then I’ll eat a little bit of it now, but yeah, I didn’t really know what to do for a while. And I felt like the oceans were kind of like in a lot of trouble, but I am glad to hear that in the bird study on toxicity, that it might not be as bad as we think if we are ingesting things like microplasty.
Denise (11m 21s): So let’s talk about that for a moment. Right? So people eat fish and now people are really afraid if I’m eating fish, I’m going to eat plastics, right. That’s Oh my gosh, am I eating plastic in the fish? That’s a question that I got sometimes anyhow, well, my answer to that is that in general, unless we’re eating sardines or anchovies and whole fish, we tend to remove the digestive tract. Right? We cut out the guts of the fish that we eat as a filet or you didn’t, you know, even eating it, quote unquote, whole, you know, eating the head and all the other parts, people aren’t eating the digestive tract and the plastics that the fish, if they have injusted plastics where they’re going to find those is mostly in their digestive tract, which we have now cut out, which means that humans are very, very unlikely to actually be getting microplastics or even larger plastics from eating fish, except in those cases where you are eating that whole fish, like I mentioned earlier.
Denise (12m 19s): So I think, you know, sometimes when we unpack the layers a little bit more, we realize, Oh, okay, maybe I don’t need to be quite as worried about that. And for me, if I was eating fish, I would be much more concerned about heavy metal contaminants and things like that. Depending where the fish is caught in the species of fish, et cetera, then I would be about risks from plastics in my fish for me, you know, that’s based upon my knowledge as a scientist, you know what I know about plastics and you know, the, the bit that I know about other contaminants out there in the environment, but that’s where people need to make decisions with the information and you know, that that’s in accordance with their belief systems.
Laura (13m 4s): So even if the microplastic it’s super, super small, it can’t really migrate out of the digestive tract?
Denise (13m 12s): Well, so it could, the probability of that is pretty low. Yes. It’s been shown in some, you know, in really good research from Chelsea Rockman that that happened, you know, in a lab experiments with you do get the migration that, you know, and that you can get that. As I said, for me, I would be far more concerned about other contaminants in fish than I would be about potential for nanoplastics or very, very small microplastics migrating through their tissues and me eating that as a result of eating fish.
Laura (13m 48s): Yeah. I remember the mercury thing for pregnant women that you weren’t supposed to eat tuna. That was an issue, but yeah. And you, you did a study on sea turtles as well. Can you tell us a little bit about that? They seem to have a affinity for plastic as well? I think,
Denise (14m 6s): Yeah, I did different life history stages, turtles feed, and live in different places. So, you know, they hatch on land and then they go into the coastal zone and then they, and then as they have what they call the lost years when they’re out feeding in, when people don’t know where they are as much. And then when they’re adults, they come and feed again in the more coastal environment, perhaps that’s where we also see them much more because humans are there much more. And then they come back on land to lay their eyes. And we’ve done a fair bit of work on turtles to look at what different species eat, what different types of plastic and where, and how do they encounter it.
Denise (14m 43s): And, you know, we actually led by Kamar Schuyler, who is a PhD student at the time. You know, we did some work where we actually asked that question, is it true? You know, people have been saying in the literature, people talk in public a lot that turtles mistake, plastic bags for jellyfish because they look alike. And we actually did some work on that to see what different types of items do turtles eat, and that went life history stage it doesn’t resemble their prey. And yes, indeed, that is true that we do find in green turtles in particular may eat plastic bags that resemble their prey.
Denise (15m 20s): One of their natural prey out as being jellyfish. You know, one of the other studies that we did that was really to look at and say, okay, what’s the risk of death due to eating plastics for seabirds in one study. And then we did another study looking at that for turtles. And what we’ve found is that a turtle that has eaten only 14 pieces of plastic has an increased mortality to 50%, which means there’s a 50% chance of mortality due to eating plastic for turtles.
Denise (15m 51s): You know, and that’s, that’s pretty dramatic, right? You know, that’s not necessarily that much plastic. And again, what we find in turtles is that mostly when we find turtles that have eaten plastic, we cannot say that the plastic killed the turtle, except in those cases where we find that real obstruction, you know, in their, in their different levels of their gastrointestinal track. One of the things that’s very different about turtles and about seabirds, however, is the turtles. It’s a one way ticket.
Denise (16m 21s): If they eat the plastic, they cannot regurgitate it. The structure of the esophagus, you know, of the throat of a turtle is very different from a seabird and seabirds are actually, they do not throw up. They cannot regurgitate it. So it must pass or else it will be lodged and stay in their digestive track. Internals have extremely long digestive tracks just because an animal eats something that’s indigestible. It doesn’t mean that that is a negative thing.
Denise (16m 50s): Sometimes, sometimes animals intentionally eat things that are indigestible because it, it helps with the physical abrasion for breaking up other food particles and things like that. The turtles have a very long digestive tract and when they eat things they can’t throw up, right? So it’s a one way passage, right? So unlike seabirds that can dispel or dislodge or discord, just Gorge food turtles, can’t do that.
Denise (17m 20s): And so if it cannot pass all the way through their digestive track, it will become, you know, stuck in there and some place along their intestines. And obviously between your intestines, you have a sphincter, right. That allows passage of blocks passage. And so if you get a blockage there, then you may not be able to pass any more material. And obviously those are instances where we could clearly identify that a turtle had died from eating that plastic.
Denise (17m 52s): The other cases where you can actually clearly identify deaths due to plastic would be something like it got per perforation that you can see, you know, a turtle AIDS, a very sharp piece of plastic, and it cuts, you know, creates a cut or a perforation in the gut. And then you can see sometimes, you know, like an infection around that. If you have a turtle that has died. And you know, I think many of your listeners may have seen or heard about, you know, there was that YouTube video that went around a few years ago about a turtle that had a plastic straw up its nostril quite far up, it’s an Austral.
Denise (18m 37s): And showing the researchers actually removing that, you know, so, you know, clearly the turtle didn’t eat that, but it became lodged in its nostril. You know? And so there are certainly impacts from plastic pollution, from our consumer items that can have quite an impact on our Marine and coastal wildlife.
Laura (19m 0s): What do you suggest that we do about all of this? So I think I learned that, you know, if we’re ingesting microplastic, it might, you know, it’s not killing us and a lot of animals can eat it if it’s microplastic and it’s not going to be too bad, but there are some things from the beginning of the study that you saw, there was like some, I think it was testicle tumors
Denise (19m 22s): In birds when we found higher frequency. So more occurrence of insists on male reproductive, organ organs. And we also found that chicks grew a little bit more slowly, and we think that’s because the plastic would have been displacing food that they were getting nutritional value from. And so you might think it’s no big deal to grow a little bit more slowly and that may or may not be true. And that may or may not be true depending upon how small or finite or protracted the breeding season is.
Denise (19m 56s): So if a bird grows more slowly and so it’s reaches adulthood a little bit later than is it able to reproduce and to have chicks and to have offspring, you know, those sorts of things. So that may or may not have as great an influence over the lifetime of a bird, for example. Yeah,
Laura (20m 15s): That’s a good point. I have chickens and there’s a point where they get all their feathers in there, much more durable. And when they’re tiny and they’ve got their little fuzz, you have to keep them very, very warm where they could perish. So even if they had like an extra day or two, I can see it though.
Denise (20m 33s): Exactly. So a couple of days here or there can actually make a substantial difference, you know, and if you arrive late, because you’re a little bit late, you may not get a good breeding spot or a nesting spot, or be able to find a mate, you know, and that may mean that then you aren’t able to, you know, reproduce and to have young that survive and all those sorts of things. So there’s some quite subtle flow on effects that, that are easy to, I think, miss at first, at first blush it, looking at some of these, some of these things.
Denise (21m 4s): So I’m not saying it’s all doom and gloom. And the other thing I would say is we don’t focus on whether it’s plastic or microplastic, right. That’s really just an artificial human construct of, is it bigger than five centimeters or smaller? And to say that something that’s 4.5 millimeters, sorry, rather than centimeters, you know, if it’s, if it’s slightly over a slightly under, that means it’s a microplastic or not a microplastic, but I think that it’s really for an animal it’s, is it big enough for me to eat and can it pass through my gut through my digestive system?
Denise (21m 41s): And so, you know, when I talk about it, I tend to talk about plastics rather than focusing on, is it a microplastic or is it a Misa plastic, or is it a macro plastic? You know, but we know that by definition, animals can only eat things that their mouse can fit, you know, that they can get their mouth around, so to speak, right? So whales, especially bailing feeders, you know, that just opened up their jaws. They can eat tremendously large sized items versus something like a very small bird can only eat, you know, much smaller types of items.
Denise (22m 17s): And again, it depends on what do they encounter in their environment. What do they come across?
Laura (22m 23s): Have there been any theories about what was causing the cysts in the toxicity study? Denise (22m 30s): So it could be from the actual plastic itself, from the polymer type. And it could be that it’s just the presence of something that’s indigestible. So we didn’t run an experiment to see do birds that ingest wood, or do birds that ingest, you know, another type of material like glass or something like that. Do they have that effect? And I think that actually points to one of the things that we see in studies today, there’s so much focus on plastics and there’s so much, I think, interest that sometimes you actually get other researchers saying like this is due to plastics, but we don’t necessarily have those tests or experiments to say does a different material.
Denise (23m 18s): That’s not plastic have a similar influence or affect or impact on that animal. If they’re eating something that’s not digestible. Does that make sense?
Laura (23m 28s): Yeah, totally. I wonder if like, if it would make a difference if they’re like stressed in a lab setting or like, what do I was thinking is maybe the plastic would have BPA in it or something if there was some sort of hormone disruptor that could do it
Denise (23m 41s): Well, and that’s certainly possible. We were using one type of consistent polymer. You know, we were basically feeding them Virgin pellets or ocean soaked pellets to see if there was higher and, you know, different effects from being environmentally soaked, meaning that there would be those environmental contaminants that they would pick up from being out there, you know, in the ocean and potentially sobbing, you know, chemicals or toxins from, you know, from the environment. But we, you know, so, and, and again, their studies are really tricky to carry out and, you know, you want to be able to do it carefully and ethically, you know, and, and because you are in more of a lab situation, then you also want to be careful of over interpreting your results.
Denise (24m 30s): Now, there is a group in Japan that has been doing some feeding trials and experiments. My understanding is with wild seabirds on their nesting grounds, but I haven’t seen those results published yet, but it’s an excellent lab that does incredibly high quality work, you know, based in Japan that in there leading researchers on plastics and toxicology and sea bids, so there are some other projects underway to try to tease apart some of these important questions, but we don’t have all the answers yet just like we don’t have all the answers to what is the human harm caused by plastics in our systems.
Denise (25m 11s): You know, that said some of the best information that we have really comes from the medical literature. And, you know, I actually have two artificial knees and people have artificial valves, you know, to help hearts function and to help joints function. And so we know that overall for there to have to be approvals, to put plastics into people, into joints and things like that, you know, there is the presumption of, of, you know, that there is not harm being done from those plastics, from those polymers being put into us as humans.
Denise (25m 54s): And I, for one am very grateful for the fact that I have artificial knees that allow me to, you know, play volleyball and, you know, climb mountains and do all sorts of fun, outdoorsy things like mountain biking. So, you know, I think the presumption that it is all harmful needs to be taken into account within the appropriate context that said, we don’t want to be eating plastics in our food. We don’t want to be, you know, mistakenly eating, eating plastics, you know, really taking the precautionary principle that we, we don’t want to be eating things that are not digestible in a whole suite of objects or items. Denise (26m 34s): Right. As humans.
Laura (26m 36s): Yeah. My, my bigger worry about eating. It is like the BPA and different like flame retardants and just things like that. But I think from what I’ve learned is that I may be not as concerned of like the microplastic, cause I’m probably just going to pass it. It just depends on more like what’s in it. I guess your, your knees are such a great point because plastic is really like a Marvel of the modern world. It’s benefited your life so much. And also like our food systems are so dependent on it.
Laura (27m 8s): So it’s so important. So when I started the show, I was like against plastic. And then throughout the three years of doing the show, I really learned to appreciate it a lot, but we have an issue with the pollution and it would be nice to kind of clean that up better and really just stop it from getting out there in the first place. And I would say, we want to be designing with the end of life in mind. You know, we want food security. We want people to be able to eat, you know, food that is safe and secure, and we don’t want it leaking into the environment.
Laura (27m 41s): We want things to be designed so that they can be recycled so that they can be reviewed so that they can be repurposed so that we don’t make it use at chocolate. Right.
Denise (29m 49s): Yeah, totally. Yeah. And you did a study in Africa too, right? So what, what I always hear in Canada everybody’s like, well, Asia is responsible for most of the ocean plastics. So like why should we care? And like, I’m not close to the ocean. So I’m going to keep using all these plastic things. And what did you find in Africa? So I think it’s a really good point and really important topic to consider. So, you know, there’s this presumption that so much is coming from Asia that also wasn’t taking into account.
Denise (30m 19s): How much of the waste coming from Asia has been shipped over there from the quote unquote developed countries where we were quote unquote recycling, which meant bailing things up and sending them overseas where they were at were, or were not managed appropriately or effectively. And so those numbers from that paper really point to the fact that we don’t have as good of data out there on the ground. And so some of the stuff that we’ve been doing is actually going out and measuring how much waste, how much plastic, how much trash, how much litter is out there in the environment.
Denise (30m 53s): And we’re doing that, not only on the coastline to say what’s going out there into the middle of the ocean or, you know, out into our coastal communities, but also looking at rivers, doing surveys along rivers and in inland areas we’ve been doing that work yes in Asia as well as in Africa. So we’ve been doing work in South Africa and Kenya did some work in the Seychelles, you know, working with and talking with other countries within the African region as well. And we find there’s a lot of variability overall.
Denise (31m 23s): What I would say is Africa as a continent is growing in terms of the number of people. Hugely, there’s a big population expansion happening in Africa and we don’t have the waste management infrastructure across the countries in Africa to be able to support that growing population and the growing wealth. So the growing middle class in those areas where people want consumer items, where they use consumer items and then where they need to be able to dispose of them or repurpose or recycle them safely and smartly and bringing them back into that economy.
Denise (32m 1s): You know, so yes, there has been this huge focus that so much of it’s coming from Asia. However, I don’t think that we have been considering due to lack of data, the potential contribution from Africa, and that’s not pointing the finger at Africa. Right. You know, if we make and produce products that come in, sachets that come in single use packaging and they’re really designed to be used and thrown away, you know, that is a substantial problem, particularly in parts of the world where we simply do not have the waste to be able to support it.
Denise (32m 41s): And where we’re where so many countries are also reliant upon tourism, you know, people coming from other countries and spending their money. And you know, so then you have the products that have been transported to these places, without the infrastructure to support the proper end of life solutions that are needed. So what we see in Africa, you know, as in, we do an Asian, other parts of the world, some really neat social enterprise groups coming to the forefront, you know, making products from flip-flops making products from rubber tires, making, you know, sandals from tires, which have been made and used in Africa for decades.
Denise (33m 23s): You know, none of that, some of that stuff actually isn’t new. Some of it’s being realized by the broader world, but you know, people were making sandals out of, out of tires and in Africa, 20, 30 years ago. So, you know, there are a lot of social enterprises that are happening and coming to the forefront, some that are new, some that are older, that are a great use of materials that have reached their, you know, their end of their designed life. However, we don’t want to just be relying on these small enterprises and the ingenuity of very creative, clever people to be getting rid of our substantial waste issue. Denise (34m 4s): That’s, it’s only going to continue to grow as we continue to make more plastic, use more plastic products and that, you know, and if we continue in the linear cycle that we have been for plastic items, Laura (34m 19s): Have you been to the Amazon?
Denise (34m 22s): Yes. I’ve spent quite a bit of time and Amazonian Ecuador. I’ve spent a fair bit of time in Bolivia. I did my PhD research actually in central America. So I’ve spent a fair bit of time in central and South America. And I did, I lived in a rainforest in West Africa for a year in the 1990s and out an attempt in the remote Bush. So I’ve been privileged and fortunate to live and work in many places. I mean, I’ve worked in the Arctic, I’ve worked in Antarctica. I’ve worked in Africa, Asia and Amazonia.
Denise (34m 53s): Yes. Sorry. That’s a long winded answer to your question.
Laura (34m 57s): Super amazing. Well, I was actually wondering in my head cause I’m obsessed with the Arctic if you’d been there, but I wanted to make the point that I was in Amazon last year and saw the same thing. You’re you’re saying like those saturates, like head and shoulders was there and I’m like these different companies that we recognize from, from, you know, Canada and the U S and whatnot. And they are selling their products in the Amazon, but they just throw everything in the river. So where I was, there was also a dump in town and I mean, the river pollution was pretty bad that I saw in Iquitos.
Laura (35m 32s): So it is this problem of, I think like companies, maybe we should take a bit more responsibility, but if we put all the responsibility on the companies, then what if they just go out of business and like, you know, thousands of people lose their jobs and then you don’t have the product anymore. So it’s actually like a very complex issue, I think, but I kind of would like to see companies take a little bit more responsibility
Denise (35m 56s): Yeah. With our products. And we’re starting to see a little bit of a shift in that. I think that the consumers are demanding that requesting it, requiring it. However you want to say it, you know, they call that EPR that extended producer responsibility. You know, I think that the sweet spot is going to lie somewhere in the middle. I think there’s certainly a role for producers, for the manufacturers. I think there’s a role for government. I think there’s a role for small businesses and consumers. I mean, nothing says that you, as a consumer at a supermarket, that you actually have to take that plastic packaging with you.
Denise (36m 30s): And what we’re starting to see is not just the red cycles or, you know, the groups that accept the soft plastic recycling, that’s typically been really low value, but we’re starting to see consumers say, you know what, I’ve got my bag here. You can take that plastic punnet that those strawberries came in and you can keep it, you deal with your waste. You know, so that’s something that consumers are starting to do is to push back a little bit and to say, I’m not going to take that home with me and deal with it. You know, at my home, you can deal with that here and what we’re starting to see as well. Denise (37m 3s): You know, transportation of waste is quite an issue in quite a topic here in Australia. The federal government has put a ban on waste exports, which is coming into play for, you know, plastic glass, paper and tires. And so that’s really changing the face of how Australia is going to be and is starting to deal with its waste. Right? So if we think about who has what role and what responsibility, and if we import products that are made in another country, does there end up being a role or responsibility for the producer to accept back the waste that was created, you know, we’re associated with their products and what would that look like? Denise (37m 49s): What will that look like in global marketplaces? What will that look like in terms of our supply chains? What will that look like in terms of changing the face of waste management and, and aware we’re starting to see waste hotspots. So, you know, what are the major companies and in what countries are they based where products are being made and what is their responsibility? And one of the discussions that we’ve been having for many years in that we’re actually starting to now see industry come out and talk about a little bit more and more as well.
Denise (38m 26s): This should there be a price on plastics so that we value plastics and treat it as a commodity rather than as waste. And I think changing that relationship and changing the language we use around it, is it waste recovery or is it, you know, is it waste? Is it trash or is it material or resource recovery? I think the changing some of the language that we use and putting a price on plastics as far up the supply chain as possible would be a substantial game changer, you know? Denise (38m 58s): And that gets back to what you were talking about regarding the producers. Is there, you know, what’s the role of producers in this, as you mentioned, you know, head and shoulders or other companies that you find when you go to Amazon or you go to the African rainforest or you go to some of the wild places on earth, you know, what are we seeing there? What companies is it associated with? Where’s it being produced and you know, and how long is it traveling to get there? So can we shorten our supply chains? Can we reduce the carbon footprint? Can we make packaging more sustainable?
Denise (39m 30s): Can we reuse certain types of packaging and at least make it a valuable commodity rather than trash?
Laura (39m 39s): And a lot of people just don’t know, like when I was in the Amazon, they would have a, you know, hope, people drink out a little plastic bags with a straw. And then I would just see the ladies kind of throw it over the boat in the side. And like, I’m sure if they knew that, you know, one of their beloved pink river dolphins could maybe eat it and maybe it wouldn’t be so good, it might get stuck in them or something. Like, I think if they just knew that they, they wouldn’t do that sort of thing. And if they couldn’t find a good place for it, maybe they just wouldn’t buy that. But then they don’t even have clean drinking water.
Laura (40m 9s): So what else are they going to drink out of? Right. So it’s a pretty complex issue. And we want them to have like clean things to, to drink out of. So even if they had like a reusable water bottle, I don’t know where they would, they would fill it up.
Denise (40m 23s): You didn’t get the clean water for up. So, I mean, I think that points to something that’s really important, right? We come with our very privileged value system and say, well, if we just teach people that this is bad, that there’ll be able to do it however they need to have, we need to have clean water. We need to have sanitation systems. We need to have some of that infrastructure that is so easy for you and I to take for granted, right? I mean, one of the cool things that I saw when I was in Liberia and that I think is actually a fantastic social enterprise, that to be honest, really speaks to plastic pollution is a small group that was basically making a rain catchment system because they get year round rain in Liberia.
Denise (41m 7s): There isn’t actually a municipal landfill that is open in the country all the time in the, in the country. Right? So in a whole country where there’s not a functioning landfill, and again, there isn’t clean drinking water there either. So what do you do? Well, if you actually catch rainwater into tanks, then you have clean drinking water, right? They have a simple filtration system. It’s a very simple inexpensive system.
Denise (41m 39s): And instead of people drinking these, you know, 300 mil or 500 mil, basically a little plastic bag with water in it that they take on the, go with them. What if you shift that? What if people can trade 50 of those water sachets and get a metal reusable bottle that then they can fill in a drink station from clean filtered water, that’s come from a roof from a building.
Denise (42m 11s): You know, those are some of the thoughts that we need to be having about like, how do we fundamentally change things? How do we start further up that chain, you know, safe, clean, drinking water is fundamental for us. And it’s something that we are so privileged to get to take for granted. But like you said, you know, what do you do? And how do you tell someone, Hey, don’t throw that overboard when you’re like, well, what am I supposed to do with it? Well, you can take it home. You can put it in your yard. You can Chuck it over into your neighbor’s yard, which is probably going to not make you very many friends.
Denise (42m 45s): Right. You know, what are you going to do with that waste? People tell you it’s bad to burn it. They don’t want you to throw it overboard. I mean, all those things, I agree, you know, how do we help people make the best decisions in what’s an, a suboptimal or non ideal situation? And how do we provide the support in addition to the education so that people can make smart and sustainable decisions? You know, I think those are really important and big questions here.
Laura (43m 16s): Yeah. Because I just think of in a ketose, for example, it would cost an astronomical amount to have clean drinking water, like an entire system, the water catchment system that you said on the roofs, did they have like chlorine in it? Or like, how are they keeping the water clean? It was stored,
Denise (43m 34s): Well, one of the best ways to do so. I actually, I live in Tasmania. I live in Australia, it’s a developed country. We drink rainwater too. We have it come off our roof into a tank. Actually, we don’t filter it. We don’t have a system whatsoever. I’m not suggesting that people do that. People have different levels of comfort for that UV. So sunlight is one of the most effective filtration systems or ensuring that there is clean drinking water. So that’s one of the things that people do in some countries is they actually put, you know, they have sort of clear panels and use sunlight for cleaning.
Denise (44m 10s): There are also simple filters. The system that we saw where people were basically taking, you know, a tank, a small, you know, rain barrel tank off the side, you know, having a gutter off the roof to be able to catch the rain, the whole system, including replacing the filters for a household cost about $300 for the whole system and filters for a year. So yeah, that can be really expensive and it could also be quite a fundamental change and growth, you know, then people also aren’t paying for water.
Denise (44m 44s): It improves their health, their improves their potential, you know, it’s a livelihood opportunity and things like that as well. So in some areas, yes, it does seem prohibitively expensive in another places, you know, jeez might not be a good social enterprise project or, you know, opportunity yeah. To really bring clean, safe water and reduce plastic waste into the environment, you know, and looking at the linkage between those two things I think is also quite important. You know, we also know that where you put, drink refill stations in other countries, figuring out where you’re going to put those, it’s going to affect how much people litter on the ground, because you know, in many places, as you know, as you kind of mentioned where we’re also a little bit lazy, right? Denise (45m 28s): We want things to be convenient for us. If there’s not a bin people, Chuck it, where other people throw trash, we find more trash accumulate there because people stop taking care of that particular area. So human behavior is a funny thing in terms of how we, how we associate what the social constructs are and what is acceptable and really striking the balance between policy and awareness to help stop making things have become way so quickly is one thing, you know, as well as thinking about how do we nudge humans into behave in ways that we want them to.
Denise (46m 6s): So that, you know, as you mentioned that the woman doesn’t throw the plastic bag over into the river, you know, so that we don’t see so much trash littering, our waterways and our coastlines and our oceans.
Laura (46m 19s): Cause I want her to have a nice, fresh drink of juice, you know, like I don’t want her to live less well off. It would just be cool if we could get rid of that plastic bag part, but like keep the juice. Denise (46m 34s): So maybe it’s a making a reusable bottle. Maybe it’s making a metal bottle, a status symbol in the community. Right?
Laura (46m 43s): Yeah. I feel like my, well, I don’t know if it’s a status symbol, but I feel good.
Denise (46m 47s): I mean, so a status symbol, meaning that it’s something that’s valued, that it’s cool to reuse something rather than to have the quick culture of use it and throw it away and having that disposable culture. Right. That’s what I mean by making it valued or valuable, making it a status symbol. I mean, I call it when old school becomes cool, right? Like we’re now using paper straws, going back to paper bags or cloth bags and all those things that happened, you know, in generations past. And so, you know, we didn’t always have, you know, plastic bottles on the go or plastic bags of water or juice and that sorts of things on the go there’s actually really increased hugely is particularly in developed developing countries, but then the last 20 or 30 years. Denise (47m 34s): So it’s, it’s, it’s actually not that ingrained or that longstanding a habit. What did we do before then? Well, we brought our own cups, which is the equivalent to bring in your own bottle. So, you know, what, if that becomes your status symbol, what if that becomes the cool thing rather than, you know, the disposable item? Laura (47m 51s): Totally. Yeah. I still see that it’s cool on like tech talk and stuff that girls are buying giant drinks from Starbucks and then taking pictures of it. And then I read on Reddit that sometimes girls would come in to the Starbucks and order that drink, take their photos for Instagram or whatever, and then throw out the drink, which is probably better for them because there’s a ton of calories and who knows what kind of chemicals, but it just seems so crazy, but it’s actually a status symbol to have like a Starbucks plastic cup. And that’s crazy to me because you’re just drinking at a trash and no offense if you’ve done this or anything, if you’re listening and you’re like, Oh, I love Starbucks, but yeah, it would be cool if we could get those cups like really nice or personable or, you know, maybe there’s a more luxury line that could come out with them. Laura (48m 40s): We used to put stickers on our nail jeans and they’re traveling Denise (48m 45s): Since everybody has the same blue Nalgene.
Laura (48m 49s): Exactly. Yeah. The, yeah, the, remember that old white like opaque white one that was like soft and probably full of BP. I think we have that one, but there was a, an important study. I did, I did want to just ask you about it was the, the awareness campaigns versus government policy because you did a study and found out you kind of like compared the two, right. So if we want to reduce Marine waste, is it better to use awareness campaigns or is it better for governments to come down and make policies?
Denise (49m 21s): I think it’s not a huge surprise that actually a combination of the two is most effective. Right? So yes, it’s good to have policies such as bag bans and zero waste strategies and things like that. Those policies that target human behavior are effective. Particularly if they come in concert with outreach and awareness, you know, campaigns, whether it’s something in the United States or in North America, you know, where you see a native American, it says like, you know, please don’t litter, which is something that I would have grown up with in the seventies or in Australia.
Denise (49m 58s): They currently have the, don’t be a tosser campaign, which I think is really, really funny and super Australian, which is basically like, don’t be a jerk, you know, like clean up and, you know, don’t toss your trash out, those sorts of things. So really the combination activities and policies is most effective. And if you actually have specific policies around illegal dumping and litter prevention and recycling and education and awareness programs, those also are, those are all affiliated with much less coastal trash, much less coastal litter or Marine debris on our coastlines.
Denise (50m 40s): We also found, which I think is really interesting that if councils have, you know, or your municipalities have a specific coastal waste management budget, even if it was just a small amount of money that went towards a coastal budget, we found fewer littered items in that area. And I think that points to the pack that where municipalities are focused on that, it means they do have more awareness of the issue. That means it is a higher priority. And so there’s probably a whole suite of other activities affiliated with or associated with that.
Denise (51m 16s): So I think that’s a, was a really useful piece of work that we did to kind of point to where should you put your efforts and where do you get the most bang for the buck? And one of the things that we’re doing right now is actually have gone back out and interviewed councils or municipalities around Australia five years later to look at what changes have happened in those areas at the local level. And we really surveyed just look at the amount of litter or Marine debris in those coastal communities as well.
Denise (51m 47s): So that we’re putting together an analysis of that to really be able to talk to what does it look like five years on? How much change has there been and has the change been in a particular direction? Do we have more legislation or do we have more outreach? Do we have more awareness campaigns or do we have more fines? You know, those sorts of things. So that’s something that we’re in the midst of right now and will be coming out soon.
Laura (52m 10s): Yes. Yeah. Yeah. I think awareness campaigns are very important and I think you can do a really great thing, but if you don’t tell anybody about it, how are people supposed to do it or use it or be part of it. Right. And I think sometimes, maybe
Denise (52m 24s): Right, people are social humans are social creatures. So seeing and learning what other people are doing has a big influence, as you mentioned about, you know, tick talk or instead of, yeah. Some of the things that people are posting about what they do and what’s cool. And so making people aware and having that social Acceptibility and social support and in some cases, social pressure to do the right thing.
Laura (52m 50s): Yeah. And you found a, you found bottle return schemes work well.
Denise (52m 55s): Yeah. So I don’t think that’s rocket science or surprising, you know, we found that cash for containers is effective. And what that means is that in the States where you have cash for containers or incentives or, you know, bottle return schemes in the United States and in Australia, we found substantially reduced beverage containers littered on the ground in those States and territories. So we did an analysis of database in the United States and based in Australia so that we can see, you know, is it just in one country?
Denise (53m 31s): Does it seem to hold true across multiple countries? And you know, really the result we’re finding is yep. Cash for containers works. If you give people an incentive, they will do the right thing.
Laura (53m 41s): Yeah. We don’t have them in our province and there’s groups trying to try to get involved with that. So if you’re listening and you’re from Ontario there, I know there’s a petition going around at the moment and the government’s trying to change rules so that you don’t have to bring your beer bottles back, or there’s not a deposit. I don’t know. But yeah, the deposits are a lot better. Cause I think a beer bottle can be used like 10 or 15 times and then like reused, right. So you’re not going through the whole carbon intensive process of recycling actually, if they are cleaning and
Denise (54m 10s): Versus if they are actually recycling. Yeah. Historically, particularly in Africa, when I lived there some years ago, now glass bottles were just reused and reused. They’d be cleaned and reused. They’d be reused for beer re reused for soda, reuse for water rather than recycling them and then creating whole new glass bottles again, you know, that has fallen out of favor in the world today where we tend to use so much more plastic than we do glass or containers.
Denise (54m 41s): However, in some parts in Europe, as well as other, other areas of the world, I think in Africa still, they do actually reuse. So they clean and reuse, but I wouldn’t, I wouldn’t have the exact figures and numbers on those, but that would certainly be less carbon costly and would be less expensive in multiple ways to actually be reusing rather than going through the entire recycling process, even for glass. But for that follow returns game, you know, that that’s true for glass and plastic and metal, right?
Denise (55m 14s): Because you can get cash for metal cans, you can get cash for plastic bottles and cash for glass bottles. For most of those returns in some places, some countries, you know, they’ve had them in place for many, many decades in different parts of the United States and different parts of Europe. And as you said, it doesn’t seem like there’s a unified program across Canada, nor is there in Australia or in the United States. Although in Australia, they are looking at putting container deposit legislation in place in men, in several of the other States at the time that we did our study, it was only in place in two States or one state in one territory within the country.
Denise (55m 57s): And the rest of the States and territories are starting to come on board with that as well as with plastic bag bans and some other legislative instruments as they call them to help support the reduction of waste lost into the environment.
Laura (56m 14s): Yeah. Yeah. I think it’s a great idea. And I’m, I’m glad that you kind of have proof, I guess.
Denise (56m 18s): I mean, I think like when you ask someone it’s like, do you think they work well? You know, most people would be like, of course work in some people and understood, you’d say no, they don’t work. I’m like, well, when you think about it, when you look at it, we actually found up to 40% decrease in the amount of beverage containers found on the ground. So, you know, we analyze the ocean Conservancy’s international, coastal cleanup data from the United States for that in the United States and then data from us as well as from some other citizen science program groups.
Denise (56m 49s): So I guess that’s another thing to really point out the highlight and value of citizen science contributions of people going out and doing those beach cleanups, working with groups, such as ocean Conservancy and other groups around the country that organize those cleanup efforts. You know, that data, that information can indeed be really, really useful. We use it for analysis that can actually help inform or underpin policy and decision making because when there’s actually scientific evidence out there that these things work, then it can encourage additional countries or States or cities to enact similar policies based upon the evidence.
Denise (57m 32s): And so I guess, you know, that’s a shout out to your listeners who may have participated in some of those cleanup events in different countries around the world it’s really, really valuable and it’s an important contribution that people can make. Yeah.
Laura (57m 45s): Yeah, absolutely. So I just want to ask you two personal questions. I know I’ve taken up a lot of your time here and I really appreciate it. This has been such a good conversation, but I often want to know, like, why do you care? Or like, why do you care about the environment? What got you into the plastics research? Really? So I guess in some ways
Denise (58m 4s): Really come full circle in the 1990s, I was privileged to have the opportunity to go work out on mid well, mid way at all in the middle of the Pacific, if you know where that is now midway between the Hawaiian islands in Japan. And when I was working on albatross out there as a young, recent college graduate, I saw so much plastic out there and we would, I, I have photos are actually images from slides long before Chris Jordan’s famous photographs of albatross with stomachs full of plastic that he took out on midway that I was taking out there in the nineties and cigarette lighters to precious bottle caps, you know, entire containers of, you know, really small containers were sometimes found in these dead birds that were there.
Denise (59m 1s): And I suppose that sort of really peaked my interest in that. You know, we also, there were also a lot of fishing nets and derelict fishing gear that was out there, you know, and you’d see monk seals tangled up in that fishing gear, that’s fishing nets. And I suppose, you know, that was long before this became so much in the public eye. And I worked in a lot of different areas and really starting to work back on plastics kind of in earnest or in anger, as they say, you know, more than a decade ago, really, it was kind of coming full circle.
Denise (59m 37s): So I’ve, as I mentioned, I’ve had the privilege to work and live in many parts of the world and, you know, really doing science that matters to people that really resonates with people. And that is impactful. You know, knowing that the work that we’re doing can help influence policy and decision making that we can actually publish something that says, Hey, this is where you get the best bang for your buck for policies and practices. Hey, this is something that really does work having cash for containers, you know, doing science like that and looking at the impacts on wildlife and the policy responses and how it moves through the environment and in training and building people’s capacity in countries around the world, as we are working on this global plastic leakage study, where we’ve worked in South Africa and Kenya and Seychelles and Vietnam and Indonesia and South Korea and Taiwan and China, you know, having the opportunity to go out and help teach people and help people in their countries to have the information at hand, to make the decisions that matter to them is a huge privilege.
Denise (1h 0m 48s): And so I feel really, really fortunate to get to work in this space on something that I’m passionate about and that I think really resonates with people and that people care about and is interest to people. So maybe that’s a long winded answer, but it started decades ago, working on a remote Island is a science geek. And here it continues to this day after having worked aboard ships to monitor seabirds, having worked in rainforests and communities around the world and working on birds and turtles and all sorts of different taxa and really focusing on people and what drives us as humans to make the decisions that we make.
Laura (1h 1m 31s): If there are any yet young scientists that are listening and they think your career path is as cool as I do. Do you have any advice for them, for people who are looking toward an exciting career in science that helps,
Denise (1h 1m 48s): I guess I’d say a couple of things, one, follow your heart to be really good at being wrong and failing. Cause that’s what we do in science. We ask questions and we learn. So you need to be good at being wrong. Surround yourself with people who are smarter than you and better at things than you. And bring those people close and work with people that have a diversity of perspectives that have a diversity of skills and acknowledge your shortcomings and be really willing to go out there and try.
Denise (1h 2m 24s): And don’t expect that you need to know everything or that you even need to know exactly what you want to do from a really young age, be willing to move in different directions and to ask questions. So be curious, don’t be wedded to knowing something and thinking that you are so smart and really definitely surround yourself with people who are, who have skills and knowledge that you don’t have and trust in yourself that you have something to offer because you do. Denise (1h 2m 56s): I guess that would be my advice.
Laura (1h 2m 57s): That’s amazing. That’s so nice. And it’s so hard for people sometimes to admit that they’re wrong. And I know some people just will, well, you know, choose a Hill to die on because they don’t want to admit that they’re wrong. And it would just be so much easier if they did admit that they were wrong.
Denise (1h 3m 9s): And, and just like, see, there’s so much when I go out and talk to school groups and things, what I say is the thing that I’m better at than anything is failing and being wrong. And you can’t let that paralyze you, but that’s what you do. As a scientist, you take risks, you ask questions, you adapt, you learn and you move on. So you don’t get paralyzed by it. And really, if you want to succeed, you got to figure out the right path or the right path, because there are many different has that will lead to those things.
Denise (1h 3m 45s): But you got to figure that out by bumping into walls and making errors and mistakes and own it, own your fault, own your flaws, own your errors and mistakes and move on. No, I think that makes us good scientists and hopefully good human beings.
Laura (1h 4m 3s): That’s awesome. That’s amazing. That’s really great. Well, Denise, thank you so much for coming on the show. It’s been really great talking to you and I’m just so happy to hear about all the studies you’ve done and your career is just incredible. So thank you.
Denise (1h 4m 14s): My absolute pleasure and really it’s not me doing it alone, right? I work with fabulous people in different parts of their career. And one of the really great things is getting to learn from people who are younger than me and who have different skill sets and you know, working in collaborative environments, which is so productive because I really do think that the key to solving these problems is bringing in different people, bringing in different skill sets and really acknowledging that, you know, the whole is going to be greater than the sum of its parts.
Denise (1h 4m 48s): Well, from the other side of the world, that was, that was dr. Denise Hardesty. She’s a principal research scientist at CSIRO oceans and atmosphere in Hobart Tasmania. Thank you, Denise.
Thank you so much, Laura. It’s been a pleasure talking with you.
Zero Waste Countdown Show 