Plastic ocean: How scientists detect and study marine microplastics | Euronews Tech Talks

[00:00:01]We're in Ostend, a city of more than 73,000 inhabitants on the Belgian coast.

[00:00:07]It's a sunny day in the middle of an early summer week.

[00:00:11]It's lunchtime and the beach is unusually calm. There are only a few children free from school and some elderly people enjoying the breeze and the pleasant sunlight.

[00:00:22]The waves roll in softly and they sound incredibly relaxing.

[00:00:29]Overall, the beach seems clean, but just because we can't see litter on the water's edge, it doesn't mean that it's not out there at sea.

[00:00:45]>> [music] >> According to the United Nations, each year 52 million tons of plastic [music] waste enter the ocean contributing to an estimated 24 trillion microplastic particles.

[00:00:57]Microplastics [music] are tiny plastic fragments less than 5 mm in diameter.

[00:01:03]They're small but have a huge impact on marine ecosystems. [music] But what technologies can we use to identify microplastics in the ocean?

[00:01:20]Welcome [music] to Euronews Tech Talks, the podcast that explores the digital, technological, and scientific landscape shaping Europe.

[00:01:29]I'm your host, James [music] Thomas.

[00:01:32]Today, we wrap up our journey into the world of microplastics with [music] an episode dedicated to their impact on the ocean.

[00:01:39]To do so, our podcast producer Alice [music] Carbonelli and our assistant producer Victoria Harrison went to VLIZ, the Flanders Marine Institute, a scientific [music] center dedicated to marine research based in Ostend, right by the Belgian seaside.

[00:01:55]Here, they met three researchers and [music] discovered how to spot marine microplastics and their impacts on the ocean.

[00:02:03]>> The plastic has nowhere to go, so it just stays.

[00:02:06]It is known that microplastics are being ingested.

[00:02:10]Plastic production is still going up, so the amount of microplastics are not decreasing.

[00:02:17]So, it's really important that we do something about it.

[00:02:22]>> [music] >> Alicia is following Anna Catarina down a boat ramp just next to the lease.

[00:02:37]Catarina is a senior researcher and leader of the plastic pollution research group at the Flanders Marine Institute.

[00:02:45]>> So, there's a lot of litter here in this boat ramp because the wind somehow pushes them here passively. It's litter that floats. It's mostly made of plastic, but not only. And we can see pieces of different sizes as well. So, we can look around. We see here some ropes from the boats, filaments, slightly smaller, but also like tops of bottles, fragments that are not really identified.

[00:03:19]>> At the boat ramp, concrete mixes with wild blades of grass, and among them lie several pieces of waste.

[00:03:26]>> Something really, really interesting, we see a lot of these lollipop or cotton net bud sticks. The cotton net bud sticks, they have been forbidden to be made of plastic, but we still find them.

[00:03:38]So, there's a lot of litter that we find that is no longer available in the market, but it's legacy litter. So, it stays in the environment for many, many years.

[00:03:50]>> Plastic cotton bud sticks are banned in the European Union under the single-use plastics directive.

[00:03:56]The ban was implemented in 2021, yet plastic cotton buds are still floating in the ocean and polluting our beaches.

[00:04:05]A plastic cotton bud can take up to 300 years to decompose.

[00:04:10]>> And what do you have in your hands now?

[00:04:12]So, I have a few small fragments, but also nurdles.

[00:04:17]So, these nurdles are plastic pellets that are mostly used to produce other plastic applications. What's interesting about them is that they're everywhere in the coast, on the roads, everywhere, because they're easily lost. So, when they're being transported, they fall off trucks, for example, or from boats. And here you can also see that there's some plants in this slipway, and usually areas with plants retain plastics, so they trap the plastics. These nurdles, you can see that they also have different, we call it weathering stages.

[00:04:57]Some are yellow, some are a bit more pristine, some are a bit degraded. The more yellow or the more degraded they are, it means that they've been in the environment for a longer time. The kind of nicer and round shape they are, it means that they're new.

[00:05:13]>> Nurdles are tiny plastic particles used to manufacture plastic items.

[00:05:18]Just like plastic cotton buds, they're also at the center of an EU regulation, which entered into force in December 2025 to reduce microplastic pollution.

[00:05:29]This law is directed at companies managing five or more tons of pellets annually and sets out clear rules to prevent plastic pellet loss in the environment.

[00:05:39]>> One to days, you already have litter there.

[00:05:42]>> And although the North Sea isn't as polluted as the Mediterranean, the effects of plastic pollution are more than visible.

[00:05:50]>> One to days.

[00:05:51]>> Yeah.

[00:05:53]>> It doesn't stop coming. [laughter] Yeah, especially if there's a wind.

[00:06:02]>> Research [music] on microplastics started in 2004 when marine biologist Richard [music] Thompson coined the term in his landmark article Lost at Sea, Where is all the plastic? [music] But how does plastic get into the ocean?

[00:06:17]>> Plastic [music] gets into the environment mostly due to either accidental loss, but also some intentional litter that is spread >> [music] >> due to behaviors that are not very nice to the environment. And also in some cases due to waste management that should be perhaps improved. So waste streams [music] that are not adequate to the area.

[00:06:42]And there's also a lot of activities at sea that can induce release of plastics [music] or other litter in the environment such as activities where you lose fishing rope, lost fishing gear. It's also a big problem at sea.

[00:06:58]>> Plastics, including microplastics, can [music] enter the ocean either accidentally or intentionally. And microplastics specifically can develop over time [music] through the degradation of larger plastic items.

[00:07:11]>> There are two types of microplastics.

[00:07:14][music] Some have been made already as microplastics and they are used in applications such as paints or cosmetics, [music] less and less fortunately. And others are just the product of breaking down of [music] larger materials, larger items that were in the environment already.

[00:07:33]And [music] with mechanical forces like the the waves, the winds, also because of the UV exposure, so exposure to the sun, they become brittle and they break [music] into smaller particles.

[00:07:51]>> But, if microplastics are invisible to the naked eye, how do scientists know how many are in our oceans?

[00:07:59]>> [music] >> There are standardized ways to quantify.

[00:08:06]For example, if we want to know the concentrations, that's what we should report. We need to know either the volume of water that the sample has or the area of uh, sand or soil where the litter is.

[00:08:20]This information [music] is shared between researchers, so we uh, try to follow similar methodologies, so then we can compare our results. And this information is also in a, ideally, shared also with our regulators, with the policy makers. For example, some of the directives of the European Commission require that we report the quantity of litter, so policy makers can also take action.

[00:08:48]>> Since it's impossible to count individual plastic particles in the ocean, researchers [music] quantify microplastics by analyzing samples and comparing data across them.

[00:08:59]Identifying these tiny plastic fragments, however, is no easy task.

[00:09:05]Microplastics [music] are challenging to detect because of their small size and diverse properties.

[00:09:11]Specifically, secondary microplastics [music] resulting from the degradation of macro litter are difficult to identify due [music] to their irregular shape and distorted chemical composition.

[00:09:21]Fortunately, a range of methods and technologies can be used [music] to find them.

[00:09:26]Annelise Meyer, postdoctoral fellow at Vrije Universiteit Brussel, has spent years researching these techniques.

[00:09:33]>> [music] >> There are different techniques to do this. For example, FTIR, so Fourier transform infrared spectroscopy, which is based on infrared spectroscopy. So, basically, uh there is an infrared beam which is directed at the particle. And so, uh the light will be absorbed by the particle, and this will create an um spectrum, so an absorption spectrum, which is very characteristic for the particle, which we can use as a fingerprint to identify the particle.

[00:10:03]So, it's very accurate. But, to analyze one particle takes quite a long time.

[00:10:08]So, imagine you have to analyze over 100 or 1,000 particles, it's very time-consuming. So, it's uh also costly.

[00:10:16]There are also techniques that use uh fluorescence microscopy, like the technique that we use, for example. So, we stain our particles with dye that is called Nile Red, so it's a fluorescent dye. And because of this, the plastic will have a fluorescent coloration, and the type of coloration tells us something about the type of the particle.

[00:10:36]>> Mayer's PhD research focused on the development of what Valiz presents as a more cost-and-time-effective method to spot and study marine microplastics.

[00:10:46]Her technique is semi-automated and built on fluorescence-based analysis.

[00:10:50]Here's how it works. The first step involves collecting the sample using a tool called the Manta net.

[00:10:56]>> This is a Manta net. So, it's called like this because it resembles a manta ray, as you can see, when it floats on the water. And so, there is also a device in here that allows you to see how much water went through the system, because we need to know it to be able to estimate the concentration of microplastics in the water. So, the water goes through, and microplastics are retained in the nets, and then we analyze them.

[00:11:19]>> The Manta net is a cross-shaped object composed of a rectangular metallic part, a long net, and a sort of thermometer to check the volume of water passing through the net.

[00:11:29]>> And this net is attached to a boat, I guess.

[00:11:32]>> Yes, usually we take it out on the research vessel and we tow it behind the boat.

[00:11:36]>> Once the sample is collected, it's processed.

[00:11:39]>> So, depending on the type of sample, we have very specific protocols. For example, we add digestive reagents to get rid of the material such as hydrogen peroxide and other chemicals.

[00:11:52]>> Once the sample is clean, it's time for the analysis.

[00:11:55]>> So, then your microplastics end up on a small filter. And then as a first step, what we do is we stain so we add the dye. And so yeah, the coloration will differ depending on the particle. And then we take pictures under a microscope. And we use three different wavelengths for this. So, blue light, green light, and UV lights. And so these pictures will then be used to extract the color data of the particles. And this will be used and combined with a machine learning technique which can then do predictions of the particle identity based on its coloration. And so the image analysis is automated. The model predictions are automated. So, that speeds up the process. And then the fluorescence microscope, it's quite affordable to buy. And because of this, labs around the world could use this.

[00:12:40]So, also those with limited resources.

[00:12:42]So, that's a bit the idea to make it cost and time efficient.

[00:12:48]>> [music] >> This part of the process is a little more tricky. So, let's try to break it down.

[00:12:54]>> [music] >> The microplastic sample is stained with Nile red dye and analyzed under a microscope.

[00:13:00]>> [music] >> This microscope takes three sets of images using UV light, blue light, and green light.

[00:13:08]The data based on these images is then run [music] in two automated programs whose algorithms decide if the particles are made of plastics and their molecular composition.

[00:13:18]>> We wanted [music] to automate so it speeds up the whole process. We wrote source codes. So, when you upload the picture, the [music] image analysis is done automatically, so the particle recognition, the color data is extracted, and it is fed into the model, and then the predictions are also [music] done automatically in an open source software.

[00:13:38]>> Like any other method to identify microplastics, [music] Meyer's technique has some limitations.

[00:13:44]It lacks information about the chemical composition of the particles [music] and can determine only certain types of polymers, so only certain types of molecular compositions.

[00:13:56]>> [music] >> Identifying microplastics is not an end in itself, but it's the first step to other studies that are essential to understand how microplastics impact the marine environment.

[00:14:10]This is Juliette Granjean, PhD student of VLIZ specializing in microplastics impact on marine invertebrates.

[00:14:18]>> So, you first select your polymer, then you need to see its shape, if it's irregular, if it's smooth, and we usually use clean plastics to have control conditions. So, you usually select the size of the particles that is within the size range of the prey your organisms are feeding on. So, for me, it's very low because my organisms are less than a millimeter in size. So, I have species that need to grow, spinipes. It's a small copepod as zooplankton. So, a very small crustacean.

[00:14:51]And what I try to do here is a have a certain concentration of plastics in their control medium, so it we try to be as in controlled conditions as possible, and then we expose them to these particles, and we assess what we call different end points, so it could be development, mortality, reproduction, so all these kind of things.

[00:15:16]>> Granjean is only at the start of her research, and she's currently assessing mortality.

[00:15:22]So far, she's not seen any impact of microplastics [music] on her sample, but this doesn't mean that microplastics don't have an impact on the species she's analyzing. [music] >> I'm not um assessing as visible or visual effects as others, [music] but it doesn't mean that if you don't see any effects, maybe you won't have another one when you do a longer period of uh exposure or if you go at the cellular levels. But it is known that microplastics [music] are being ingested. They can abrade the digestive tract or block it completely.

[00:15:57]The organisms can also [music] suffocate. There could be delay in their development, in reproduction.

[00:16:04]>> Microplastics effects are not only related to the exposure time and to the type of marine species analyzed, but also to other factors, including [music] sea temperature, acidification, and chemicals.

[00:16:17]The list is long, [music] and research on microplastics is still in its early stages.

[00:16:23]>> [music] >> After all this science and lab talk, you might be thinking that marine microplastics have nothing to do with us humans.

[00:16:34]How could a microplastic particle eaten by plankton possibly affect someone living in Berlin? Why should that person care?

[00:16:42]Nella Meyers has the answer.

[00:16:45]>> It's a concept that is called one health, meaning everything is interconnected, the environment, the species in it, and us as humans, because everything that ends up in the organisms, it can go into their blood flow, and that way if we eat them, it can also affect us because the plastics end up in our stomach, can go into our blood flow, to our organs. So, everything is interconnected.

[00:17:10]>> One health is an integrated and unifying approach, [music] considering that the health of people is closely linked to that of animals, ecosystems, and vice versa.

[00:17:21]This approach [music] is widely recognized and at the heart of major organizations such as the United Nations.

[00:17:29]The concept has ancient roots that go back to the 19th century, but was brought back to the spotlight with the outbreak of the COVID-19 pandemic, [music] which clearly showed the close ties between environmental, human, and animal worlds.

[00:17:43]And as everything is connected, climate change, the heat waves, and unpredictable weather we're [music] experiencing this summer are to some extent connected to microplastics and the other way around.

[00:17:55]Here's Ana Catarina.

[00:18:00]>> Plastics are oil derivatives, and of course, the more we produce, it means that the higher the release of CO2 is to the atmosphere, and that affects climate change. We also know that the fact that there is, for example, microplastics available to organisms that may ingest them, perhaps the effects are not [music] immediate in this organism, but if they are vulnerable due to climate change, due to a heat wave, for example, these combined effects that can be cumulative [music] in the organism, so the organism may not be able to feed properly or to reproduce properly, and this may impact populations in [music] the long term, for example. So, if we have more sunny days and higher UV radiation exposure and heat waves and changes of temperature that might, for example, impact the degradation of plastics that are [music] stranded. But, there are also people looking into more complex things like the carbon cycle. Are the plastics affecting this carbon cycle in the ocean?

[00:19:02]Is the fact that plankton may ingest or may interact with plastic affecting also the dynamics of [music] plankton, and how does that impact climate change?

[00:19:10]There's indication that potentially it might [music] have an impact, but I >> There's still a world to be discovered when it comes to the effects of microplastics on marine species, humans, and the environment.

[00:19:28]Research into these particles began relatively recently and is still ongoing as scientists work to better understand the risks they pose.

[00:19:37]As this episode comes to an end, we hope we've not scared you about microplastics, but instead informed you about what we know so far.

[00:19:53]That's it for today's episode of Euronews Tech Talks. [music] If you're interested in discovering more about this topic, listen to episode 74 and 73 of Euronews Tech Talks. And if you want to put faces to our interviewees, keep checking our website.

[00:20:10]We'll soon release a video of our experience at Velis. [music] A reminder that this is the last episode of Euronews Tech Talks before the August break. We'll be back in September with more stories about the scientific and tech landscapes shaping Europe.

[00:20:26]If in the meantime you want to stay in touch, don't hesitate to reach out to us. [music] You'll find our email in the podcast description.

[00:20:35]Have a great relaxing August. We'll meet you back here soon. Thanks for listening.

[00:20:43]>> [music] >> I'm your host, James Thomas.

[00:20:48]This series was created by [music] Marta Rodriguez Martinez.

[00:20:52]This episode was written and produced by Alice Canales.

[00:20:56]The theme music is by Leo Lebron.

[00:20:58]>> [music] >> Sound editing and sound mixing is by Yoann Breton.

[00:21:03]Our editor-in-chief is Ali Isam Aiden.

[00:21:07]Thanks to Victoria Harrison, assistant producer for this [music] episode.

[00:21:11]If you aren't already, you can listen to this series on Apple Podcasts, Spotify, Castbox, or wherever you get your podcasts.

[00:21:20]If you're enjoying the podcast, please consider leaving [music] us a positive review, and of course, sharing it.

[00:21:26]Thanks for listening.

[00:21:32]>> [music]