Welcome to the Marine Biologist podcast join us to discover the
latest topics by leading marine researchers and
conservationists. The podcast accompanies The
Marine Biologist, the magazine for members of the Marine
Biological Association, as presented by the editor Guy
Baker. We're really pleased to welcome
today Doctor Alice Horton, Senior Research Fellow at the
Marine Biological Association. Welcome Alice.
Thank you. What was your route into marine
biology and how did you get specifically into microplastics?
I think I have a similar story to many people in this field in
that I've always been fascinated with the ocean ever since I was
little. I think the scale of it and how
unknown so much of the ocean is really drew me towards it.
But I actually started my study in more broad biology, so my
undergraduate degree was biology.
It was during that period that I carried out a research project
looking at the effects of pollutants on moon jellyfish and
I worked within an aquarium facility, so behind the scenes
at the Sea Life Centre, and I found that absolutely
fascinating and it really drew me to want to research marine
biology further into the future. So after that I pursued an
Oceanography MSC with a focus on marine biology and ecology, and
after that point I went to work at the Centre for Ecology and
Hydrology and they were advertising a position for a
research associate looking at microplastics and toxic
pollutants. And at that point in time, it
was 2014, I think, nobody had really heard of microplastics,
nobody really knew much about them, so not many people were
doing research in the UK. And it was a really good
opportunity then for me to develop the UK research on
microplastics, specifically in fresh waters, which is what
UKCEH were focusing on at that point in time.
And that really enabled me to develop and to put my stamp on a
new and burgeoning field. And over the years I've moved
between terrestrial systems, so soils, fresh waters and now more
in the marine environment, covering things such as looking
at where plastics are coming from and where they accumulate
in the environment, but then also these biological and
ecological interactions leading to toxicological effects.
The podcast follows on from an article that you've written for
the Marine Biologist magazine. And in that article you point
out there's so much we don't know about plastics,
microplastics in the in the environment.
So what are the particular challenges of working with
microplastics? So I mean, plastics in general
are relatively new contaminant if we think about the scale of
human existence, because we've only really been commercially
using plastics since the 1950s. But one of the issues with
plastics of course, that they're very persistent, but they're
also very diverse and very heterogeneous.
So there are, you know, thousands of different polymer
types really if we break it down.
And then within those we have a multitude of different chemical
additives. These can enter the environment
of course and plastics breakdown into smaller and smaller pieces.
So they are not really, we shouldn't really consider them
as one contaminant plastics. We really need to think of them
as a sort of diverse suite of chemical contaminants that are
all interacting and behaving in different ways.
And this poses problems when we want to try and, well, A, work
out what the effects of plastics will be on organisms, because
this will vary depending on the material that you're looking at.
But then B, look for these materials within the
environment. So if we're trying to find
microplastics in environmental samples, A, they're very small.
So the scale of a microplastic is defined as anything between 5
millimetres and one Micron. So quite a diverse range.
Still 5 millimetres you'd be able to see with your naked eye.
One Micron, absolutely not. So trying to find these things
in themselves can be quite challenging.
Trying to determine what they're made of, where they've come
from, and what the effects are all relies on quite
sophisticated analytical techniques that are still really
in development. So the ways in which people are
doing this research continues to evolve and has done quite a lot
even since I started in this field a few years ago.
Can you give us some detail about the direction your
research is gonna take here at the NBA?
Yes. So to date, my research has
really focused on 2 categories. It has been environmental
accumulation of plastics, so trying to understand what's in
the environment and where it's going and how it's behaving.
And then on the other hand, it's trying to understand the effects
of those plastics on organisms and ecosystems that are exposed
to them. And what people have done so far
is generally keep those things reasonably separate.
And the experimental studies that have been carried out to
look at the effects of plastics generally look at plastics on
their own. So don't necessarily or are not
necessarily able to consider the really complex environmental
interactions that will actually be at play when we're looking at
what is happening in the environment.
So what I'm trying to do with my research is trying to make it
more environmentally relevant by running experiments that account
for wider environmental factors as well as plastics and
specifically additional stresses.
So things like climate change stresses in the form of things
like increasing ocean temperature and then also
chemical stresses. So we know that there's a huge
diversity of toxic chemicals and persistent chemicals that are
entering the environment and trying to understand how if we
have microplastics and these chemicals in multitude of
combinations in the environment, what are the combined effects of
those on the organisms that are exposed?
Because we know, for example, if animals are exposed to climate
change effects, they might be less resilient then to the
effects of another pollutant that's occurring in the
environment. So it might make them more
stressed or it might cause greater harm than if those
things are occurring in isolation.
And the other thing with plastics and chemicals is that
they are known to bind together with each other.
So if an animal, for example, ingests a piece of microplastic,
there's a high chance, well, an almost certain chance that that
is associated with a variety of different chemicals.
And those can have different effects again than if they were
present as separate contaminants.
So it's really trying to understand the greater
complexity that we have in the environment compared to some of
the studies that we've been able to carry out to date.
And does that, will that look like sort of you've got hundreds
of types of plastic, thousands of chemicals?
Well, how do you narrow down what you're going to do?
Is that laboratory experiments with sort of specific cocktails
of plastics and. Exactly, exactly.
I mean, we are never going to be able to test everything.
So it's about choosing things that are the most representative
of what we are likely to find in the environment and also trying
to identify what we believe may be the most hazardous based on
the research that's been done to date.
So specifically, choosing polymer types that we know to be
very abundant in the environment.
So things like polyethylene and polypropylene are very widely
found in the environment because they're used in a huge array of
different products that we use day-to-day, including packaging
materials and so on. We've got things like nylon and
PVC that we use in clothing and building materials and so on.
So it's about narrowing down where we really think of a key
problems in the environment and then assessing the impacts of
those. Because yes, like you said, it's
it's impossible to analyse everything and anything and
everything. What do you enjoy most about
your job? I really think for me it's the
fact that science really keeps you on your toes and you don't
always know what to expect. So there are lots of challenges
that you can face practically in terms of doing lab work.
So things don't always go to plan.
I mean, when we're doing science, by its nature, it's
something that's brand new. So we're trying to do something
that hasn't been done before. That means that often we don't
really know how to do it. We have to develop the methods
enable to do it, so to be able to understand that those
challenges will face us and overcome those so that we can
get the data that we want. And then also often the data
don't always show what we expect, so we can have
hypotheses about what we expect to happen.
That's not necessarily what actually is the result that we
see. So it can be really interesting
in that way in that it challenges our understanding of
what we believe to be the case. Also, my job is very diverse, so
I can spend days, you know, working with organisms in the
lab. I can be analysing data at my
desk, or I can be at a conference presenting my data to
stakeholders or even in Parliament, which I've done
before now. So the ability to, you know, get
out into different environments to communicate with people from
all walks of life is really something that I enjoy a lot.
Back to microplastics research going on at Plymouth Marine
Laboratory, it's going on into tire Ware particles.
And there was a, a fact that came up in an article that some
of the researchers have written for the magazine that as an
estimation of about 5065% of all microplastics released into UK
surface waters come from tire Ware particles.
So that's a that's quite a shocking statistic, isn't it?
Is that, is that something that just is is is it the sort of new
discovery that that's that volume of microplastics comes
from Rd. effectively? Yes, I'd say that's a relatively
recent understanding that we've come to and it came later almost
than the initial research on microplastics because people
that were doing microplastics research were finding unknown
particles in samples that are very difficult to analyse
because they are chemically quite different tyre particles.
But because they are a synthetic rubber, that's a Solomon
particle, they are still considered to be micro plastics.
But I think if you think about it, it is relatively obvious
that those will be in the environment.
Because if you think about your car tyres and how often you need
to replace those, it's because they're wearing and they're
going bold. That rubber that used to be on
your tyre is no longer there. So it has to be somewhere and
that somewhere is out in the environment.
So the particles shed on the road as you're driving and Rd.
drainage systems mean that a lot of those particles are released
into, well, either into the surrounding environment of the
road or into the river systems that the drainage releases into.
So yes, it is reasonably shocking, I would say, but also
now that we're looking at it, it's not very surprising.
I'm struck by how poorly designed designed many plastic
products are, having things like bags for life.
I've got a bag for life in my shed and it's, it's clearly
reached the end of its life because it's falling into tiny
little plastic particles. And it, I think it's, and, and
how much plastic we allow to leak into the environment.
And in your article, you say that amount of plastic predicted
to enter the ocean will triple between now and 2040.
So that's, that's another shocking statistic on top of
everything that's in there already.
What's going on? Do you know what's going on sort
of nationally and internationally to sort of
tackle that flood of plastics into the environment?
Yeah, I mean, the key thing internationally is the global
plastics treaty negotiations that are ongoing.
So this is attempting to come up with a global international
treaty that will agree on ways, legally binding ways that we can
reduce the amount of plastic that's released to the
environment. So this covers things like caps
on plastic manufacture, changes to recycling systems and so on.
The issue with the treaty is that all parties have different
priorities when it comes to the things that they want to get out
of it and the things that they are and are not willing to do.
So those negotiations were due to conclude at the end of 2024.
No agreement was reached and so those negotiations are ongoing.
How long that will take and where it will end up, I think
nobody is fully certain yet. So we can hope that there's a
positive outcome from that. But at present, I can't say
where or when that will happen. I mean there are other efforts
that are ongoing at a much smaller scale, I would say.
So if we think nationally, well, the one of the first things was
the plastic bag tax, which doesn't seem like a big deal,
but there was some evidence to show that that reduced the
amount of plastic bags used annually by 80% quite rapidly.
We've got things like the micro bead ban, which covers micro
beads are added intentionally to cosmetic products that are
designed to be washed off your skin.
So things like face scrubs that has obviously had some reduction
in the amount of plastics that are entering the environment.
I think one key thing to note about that ban is that it
doesn't consider products that are designed to be left on your
skin. So there are many cosmetic
products that can still contain plastics, you know, like eye
shadows and face creams and things that might have
shimmering that can still contain plastics.
So it's a step, but it's not, you know, going all the way.
And then things like plastic cutlery and plastic straws are
now no longer allowed to be used.
So there are small steps that are being made.
And these are also happening in many other countries globally.
But I think if we're actually to have any effect on the amount of
plastic that's being entered, well produced and entering the
environment, it really needs to come from policy makers and
industry. And industry are really the key
players here. And of course, you know, it's
their industry that is creating their revenue.
So they are trying to, you know, needing to work out ways in
which they can still maintain their income but actually have a
beneficial impact by reducing plastics.
And I think that's where the challenge is at the moment.
And there there are alternatives, aren't there?
There are alternative materials we can use to make what you know
what's currently disposable plastics.
We can make container food containers and and wraps for
food and so on. Do you what what is the most
promising natural alternatives to plastic to do you think that
you've seen? I mean, it is opening a bit of a
can of worms, I think if we talk about biodegradable plastics,
because even those are not always as beneficial as they
might claim to be. So there are many studies
showing that some biodegradable plastics can be as hazardous, if
not more hazardous than conventional plastics because a
lot of them are still manufactured in similar ways and
have a lot of the same chemical additives put into them.
And then we have different terminologies.
So we have things like bioplastics that come from
biological feedstocks like starch and potatoes and things,
but are chemically transformed to become a plastic.
So they're actually chemically identical to plastics and they
won't break down. Then we've got biodegradable,
then we've got compostable. And all of these types of
plastics will will behave in different ways.
So I would say it's very difficult to say that there's
one key solution in these novel materials.
I mean, there are people who are developing materials out of
seaweeds, for example, that are a lot more natural.
They're not very widely used yet.
So there are, there is scope, but we're not quite there.
I think for alternatives, really it should be things that can be
reused rather than things that will be discarded or recycled or
composted. So things like having a glass
container on the plastic container or having a metal
coffee cup instead of a plastic one, I think that's really the
way we need to be thinking about this system rather than the
disposable way in which we're thinking about it at the moment.
And do you think using technology to clean up the seas
is a sort of, do you think there's any future in that, like
you've seen these big schemes where booms float around or and
and scoop up surface plastics or the development of microbes that
can digest plastics. Is that a sort of valid focus
for sort of research and investment?
I mean, you've, you've mentioned 2 very different angles there.
So you've mentioned the booms and the collection of plastics
from the ocean and then the microbial degradation.
And so I'll address those separately.
The collection of plastics from the ocean, I personally don't
feel like it is a widespread solution for plastics in the
ocean because no matter how much they clean up, it's it's nowhere
near the amount that's in the ocean.
It's only collecting things that are floating on the surface.
But we know that actually around 99% of plastics in the ocean are
below the ocean surface. And of course you've got the
carbon footprint issue of huge ships going out into the middle
of the ocean to scoop up plastics and other associated
materials. So potentially, you know,
organisms as well. So I would say we need to
proceed with caution if we're to recommend solutions like that.
You know, I think if we're thinking about cleaning up, then
possibly some of the better solution or solutions or actions
that we can take are on a more individual level.
So community groups going out and doing cleanups.
It's not necessarily going to, you know, it's definitely not
going to solve the global problem, but it raises people's
awareness. It makes people see what's out
there in the environment, how they as individuals and
communities might be able to make a difference.
So I am in favour of of community cleanups.
You talked a bit about microbial degradation and that's something
that we are looking into a little bit here at the NBA.
Actually, one of my PhD students, Marine Fleeler, is
going to be looking at whether there are microbes that can
degrade certain types of plastics in association with
organisms as well in the environment.
Again, at a very large scale. That's unlikely to be a solution
that we can implement because we can't, you know, we can't just
put microbes into the environment without there being
some sort of ecological effect of that.
But whether in the future we could develop some sort of
degradation plants, let's say that are representative of, you
know, it could be a recycling a facility or a waste management
facility. And then we've got a microbial
degradation facility for some of the compostable and
biodegradable plastics, then maybe that could be something
that would work its way into our future systems.
So there are ways in which we can deal with this.
But I would say actually as it currently stands, we really need
to be thinking about this top of the chain approach to preventing
the production and the release of plastics into the environment
rather than trying to create all these solutions for cleaning it
up. Because ultimately, how much is
out there is is way more than we can ever deal with.
How does plastic get into the food chain?
We've heard it gets into the food chain and various sort of
facts come up in the news about how much we're carrying around
in our bodies and so on. How to get into the food chain?
What are some of the effects it can have once inside an
Organism? And is there any reason to
believe that humans are less vulnerable to impacts from
microplastics? Yeah.
So the key route of entry for any animal or human really is
ingestion of plastics. So if we're thinking about
marine organisms and ecosystems at the variety of scales
plastics can be ingested. So we see and historically have
seen a lot in the media about these sort of charismatic
megafauna that are ingesting plastic bags, for example.
So seals ingesting plastic bags because they can't very easily
distinguish the plastic bag from a jellyfish that would be as
natural food source for example. So organisms unintentionally
ingesting plastics. If we're thinking about
microplastics, then it's essentially the same but on a
much smaller scale. So we've got organisms that are
seeing microplastics and their planktonic food all in the same
system. They're not very easily able to
differentiate between these different types of particles, so
we'll just eat a lot of everything that's in the
environment. And the trouble with plastics is
that once they're internalised within the gut, then it can be
quite difficult for those to be egested again.
So they end up trapped within the gut and possibly even
entering into the tissue of that Organism.
If we're looking at organisms at the bottom of the food chain,
especially things like plankton, large volumes of these we know
get ingested by higher trophic organisms.
So plankton will be ingested by fish, which will be ingested by
birds and so on. And that leads to this bio
accumulation of plastics and their associated chemicals into
these organisms that are higher up in the trophic web.
And of course that's where we as humans are ingesting these these
organisms. So things like very large
predatory fish like tuna and so on can end up carrying loads of
plastics and contaminants that are associated with those.
So that's one route for humans to ingest plastics.
Another one is just the fact that we're surrounded by
plastics all day every day. So, you know, the clothes we
wear, the things we are handling everyday, you know, our
technology, our cars and so on, are all made of plastic or have
plastic parts within them. And those, as we use them, shed
smaller and smaller pieces. So we can be ingesting those as
they land on our food. They might be in our food
already incorporated because they're seafood, for example.
But also we're inhaling those particles because we know that
those are around us in the air that we're breathing.
So there are many routes in which humans can be exposed to
plastics. In terms of the effects of these
plastics, they vary a lot depending on the species that
we're thinking of and also the shape and size of the particle,
for example. But it has been shown that
plastics can have a variety of different hazardous effects to
organisms. So in terms of by accumulation,
we then see immune responses developing, changes in hormone
production, these things that can affect the growth of the
Organism and the reproduction and even DNA damage and cell
damage as a result of particles associating or entering the
cells. So we do know that there are
potentially quite harmful consequences of those.
And that would not be any different for humans because,
you know, biologically a lot of those processes are very similar
in terms of hormones and cells and DNA.
Not so much research has been done on human health and
microplastics, but it's definitely a very, very rapidly
developing field. And I would say it's something
that we should be concerned about.
You know, I'm not telling everybody to go out like
panicking and screaming around, but it's something that I think
we need to be aware of in terms of our exposure to plastics
because, you know, plastics have been around on such a short time
scale proportional to human life.
You know, they've not even really been commercially used
for a whole generation because you know, 1950s to now with the
75 years of commercial plastic use, there are people alive who
never plastics when they were born.
And I think for that reason we can't really assess the effects
of plastics throughout a whole lifespan of a person.
And so that is is quite worrying considering how much we use of
plastic these days. But the research can only
continue and can help us to improve our knowledge of that,
to understand how we might be able to mitigate our exposure.
So it's the one pretty difficult question.
Is the one kind of single action a person can take to reduce
their exposure to micro plastics.
Well, there are a few, but I'd say if I was going to say one, I
would say think about the soft furnishings and materials that
you have within your house. So things like your carpets,
your sofas, your bedding, your clothes and all those things
because one of the most predominantly found particle
shapes in the environment is fibres.
So micro fibres and those are all derived from textiles.
So all the things I've just mentioned.
Of course inside your house you're in an enclosed system
essentially you're closed off from the world.
So you know, sometimes on a sunny day you can see a beam of
light coming through the window and you see all those dust motes
floating around in the air. Now a lot of those will be micro
plastics if you have plastic furnishings in your house.
So things like polyester and nylon are common ones that you'd
find in in soft furnishings. So I would say, you know, it can
be quite expensive to buy natural materials instead of
plastics, but where you can just start thinking about using those
natural materials instead of these synthetic ones, because
especially inside inside buildings, it's really notable
the exposure. Yeah.
Interesting, I thought you were going to say drinking water but.
No, I mean that I could. I could list many drinking
water's. Interesting, because I've done a
study on drinking water in the past and our study deduced that
actually you're more likely to be exposed to plastics in
drinking water from plastic bottles, so like mineral water
in bottles, than you are from tap water because of the bottle
itself. So if you're buying water that's
in a plastic bottle, you think it will be pristine because it's
come from a spring up a mountain somewhere.
But actually the fact that it's been packaged isn't in lending
it to be more contaminated than water that's gone through such a
rigorous treatment process before it reaches our tap.
It's actually less contaminated. I've sort.
Of touched on this before. How important is consumer
awareness in tackling marine plastic pollution and, and do
you think, I think we we did touch on this and do you think
real significant change in the amount of plastics in the
environment has come from above from regulation?
Yeah, I think like people, power is important and can have great
impact on the way in which things are done.
So I think for society to be aware of plastics and willing
and eager to change the way in which plastics are used is
really important. So I think part of the messaging
that I try and get across as a scientist is that we can,
individually, you can make a small difference whether you're
reducing the amount of plastic you use, whether you're doing
cleanups, whether you're simply just communicating this to your
wider friends and family. However, that isn't the
solution. I think long term it does have
to come from above. So, you know, society can do as
much as they like. And I think we're very
privileged in the Western society because we have the
opportunity to go plastic free in a lot of instances.
Whereas if we look at a lot of developing countries, often they
won't have access to foods that aren't wrapped in plastics or
cosmetic products or care products that don't have
plastics. And they just often will, you
know, take what's available on their local market, for example.
So I think we need to be aware that the actions that we are
able to take in our country are very different to what a lot of
people globally will be able to do.
And I think, you know, really it's these huge conglomerates
that are producing, mass producing this plastic for the
variety of needs that we'll need to be thinking actually what can
we do that's a bit different? How can we recycle more?
How can we make products that are reusable that can go back
into a system? So things like the deposit
return schemes where you can put your bottle back in and get your
deposit back and thinking about how things can be reused, well,
firstly not produced as much, then reused and then recycled.
So it's that classic reduce, reuse, recycle.
So firstly reduce what you're producing.
If you can't reduce it, then at least reuse it.
And recycling should be the final resort.
But I think the way it stands at the moment is recycling is sort
of the default in a lot of cases.
And even then, we know that the recycling system isn't perfect.
And a lot of things that are supposed to be recycled often
can't be because they're dirty or they're contaminated and it
just doesn't work within the system that exists.
So I think the only solution really is through industry, but
they might need a prompt from policy, which is why I think
policy is really key as well. So you're clearly really engaged
with the sort of impacts of your research and that sort of policy
implications and so on. So how do you sort of how do you
work out that balance between wanting to get in the lab and do
science and then the sort of the kind of policy and apply side of
it? I mean, I think I would say
day-to-day, the science and the hands on element is is my bread
and butter. So that's what I'm doing.
But I will take opportunities where they present themselves to
communicate science all the way from primary school children to
government, you know, wherever possible.
So often it's, you know, taking invitations to go and visit
groups or to go and give presentations at different,
different events. Sometimes it is reaching out to
somebody and saying, you know, I've got a, a piece of data that
I think is really key. So for example, putting out a
press release or communicating about a piece of research that
I've done where that's appropriate.
But I would say, you know, day-to-day it's about gathering
that data. You can only communicate so much
without actually doing the work. So I think the the science comes
first and the communication is just a natural result of that.
And I think it's really because this is such a high profile
topic that I find it's very easy to communicate it because people
are interested and people already know a little bit and
they want to know more. So I think that works a lot in
my favour when it comes to speaking to people about this
issue, that people are very receptive generally.
What would be your advice to a young person who's considering a
career in marine biology? I think I would say take any
opportunity that you can that's available to you to try things
out and do things that are interesting.
So if you're able to do volunteering, I think that's
really beneficial because it gives you an experience of
working within an environment, whether it's overseas or in the
UK. So I've worked at a couple of
aquaria where I've just done, you know, technician work behind
the scenes, cleaning tanks and things just to get a sort of
hands on feeling of working in a watery experimental sort of
environment. Which really helped me to
understand really what it's like to work within a sort of hands
on environment for that kind of research.
And I think do what interests you because you have to be open
to going in different directions.
And I think if you're too rigid in exactly what you want to do
it, it may be closes off other opportunities to you.
So you might see an opportunity that's maybe not exactly what
you were thinking that you wanted to do, but it could lead
on to something else. That's really interesting.
So almost with me taking that microblastics job in the first
instance, it wasn't that I was looking for a job in
microplastics because I didn't really know what that was.
I just took it because it sounded quite interesting.
And it's ended up leading from where I was then to where I am
now. And I could never have predicted
that. So I think just be open to
opportunities, I would say. Great.
Well, we're going to follow your research with interest, Alice,
and we're going to be hopefully having more articles from you in
the magazine. Yeah.
So thank you very much Doctor Alice Horton, and all the best
for your research here. Great.
Thank you for having me. It's great to chat.
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