GeoLog

GeoLog

GeoTalk: Investigating the transport of plastic pollution in the oceans

GeoTalk: Investigating the transport of plastic pollution in the oceans

Geotalk is a regular feature highlighting early career researchers and their work. In this interview we speak to Erik van Sebille, an oceanographer at the Grantham Institute at Imperial Collage London, and winner of the 2016 OS Outstanding Young Scientist Award. As an expert in understanding how oceans transport all kinds of materials, from water and heat through to plastics, Erik has gained detailed knowledge about how water masses move, particularly how they travel from one ocean basin to the next. He has applied his knowledge to understanding problems with societal impacts, such as what dynamics govern drifting debris that collects in garbage patches and the pathways of the Fukushima radioactive plume. 

First, could you introduce yourself and tell us a little more about your career path so far?

I am a physicist by training, with an PhD in Physical Oceanography from Utrecht University in the Netherlands. After finishing my PhD in 2009, I did a two-year postdoc at the University of Miami. In 2011, I became a Fellow and lecturer at the University of New South Wales in Sydney, Australia. And then in early 2015 I came back to Europe, as a lecturer at Imperial College London. So I’ve been moving around a bit, living and working in three different continents in the past 5 years. It’s been a fantastic journey and I’m really happy to have lived in such beautiful and fun places.

During EGU 2016, you received the Outstanding Young Scientist Award from the Ocean Sciences Division. You presented your recent work on modelling the global distribution of floating plastic pollution in the oceans. How big a problem does plastic pollution present to our oceans and why should people care?

It’s shocking how much plastic there is in the ocean. Quite literally these days, it’s hard to go to a place in the ocean and not find tiny pieces of plastic. In nearly every surface trawl, sediment sample, or biopsy we take, we find plastic.

However, while we find  plastic everywhere, we have no idea what its global extent is. There are really only two numbers that are known with some confidence in the global ocean plastic budget: the total amount of plastic floating at the surface today is in the order hundreds of thousands of tonnes. And the total amount of plastic going into the ocean in a single year is in the order of 10 million metric tonnes. So the flux is 2 orders of magnitude larger than the stock. In other words, more than 99% of the plastic in the ocean is not at the surface!

How, exactly, do you go about building the  models which help you investigate where the plastic in the ocean waters is?

My research tries to find out where all this plastic is, by tracking it virtually in high-resolution Ocean General Circulation Models such as NEMO.  NEMO is a large European computer simulation that replicates the movement of ocean water around the globe. Within this oceanic flow field, we’re literally tracking billions of virtual plastic particles, from their sources on land as they are carried around by the ocean currents.

The difficult bit is to make the virtual particles behave like plastic. In order to realistically simulate the pathways and fate of the plastic, we need to simulate fragmentation (how plastics break up), ingestion (animals who eat plastic), biofouling (how algae grow on the plastic), beaching (how plastic particles end up on coastlines) and a dozen other processes that happen to plastic in the real ocean. That’s what my team and I are working on!

Then, once we can track the plastic within models with reasonable accuracy, we can start asking important questions like: Where are ecosystems most at risk? Whose plastic ends up where? And where can we best clean up the plastic?

Erik, along with colleague David Fuchs, created Plastic Adrift.com. A page which models the journey of plastics in the oceans. The research used to create the page is described in this IOP paper: http://iopscience.iop.org/article/10.1088/1748-9326/7/4/044040/meta;jsessionid=3C17B7D3F10B29C6CCF1BD2BA132BF76.c5.iopscience.cld.iop.org

Erik, along with colleague David Fuchs, created Plastic Adrift.org. A page which models the journey of plastics in the oceans. The research used to create the simulation is described in this IOP paper.

So, are you at a stage where you can reliably track particles of plastic in your simulation? And if so, what can you tell us about the distribution of plastic across the world’s oceans?

No, we’re not nearly there yet. We’re just beginning with this exciting project, which was awarded a large European Research Council Grant this year. Ask me again in five years 😉

The outlook isn’t positive, so, how can we go about mitigating the problem?

The situation is pretty dire, indeed. Global plastic production has increased exponentially over the last decades, and there is no reason to think that exponential growth will slow. So the main aim should be to prevent plastic from going into the ocean in the first place.

Last May, I was invited to the UK Parliament to give oral evidence to a Select Committee about my thoughts on a country-wide ban on microbeads used in cosmetics (an issue which has been in the news recently). Such a ban is now supported by the UK Government, which is fantastic news. But microbeads from cosmetics represent only 0.1% of all plastic entering the ocean from the UK. There is really much more work to do. We need better filtering of plastic particles and fibres in sewage treatment plants. We need much better recycling techniques. We need innovative new plastics that are less harmful.

And we need a better understanding of how the plastic in the ocean interacts with marine life, from charismatic megafauna down to phytoplankton and microbes. In particular, I call on EGU’s ocean biogeochemistry community to take up the challenge of understanding the interactions between plastic particulates and biofouling. There’s such an enormous knowledge gap there, and we need all the help we can get.

Given your experience advising the UK government on a matter as significant as plastic pollution in the oceans, how important do you think it is for early career scientists to play a role in advising policy-makers when it comes to environmental issues?

Meet Erik! Credit: Erik van Sebille

Meet Erik! Credit: Erik van Sebille

I think it is extremely important to make sure that your research gets out to the people who can use it to make decisions. Politicians and other stakeholders are always keen to hear about the latest science; they don’t have time and expertise to read through all of the scientific literature so it is partly up to us scientists to point them to the latest findings. It doesn’t matter whether you are an early career researcher or a seasoned senior professor, if you are funded by public money then you have a duty to give results back to society.

For the past twelve months the EGU has been working on developing its science for policy programme. ‘Science for policy’ involves applying scientific knowledge to the decision-making process to strengthen the resulting policies. If like Erik, this is an area you are interested in, or one where your research findings could make a difference, why not visit our policy pages on the website? They include  a range of resources aimed at informing scientists about the world of science policy and initiatives to help you get involved.

Erik, thank you for talking to us today. Our final question of the interview is, perhaps a little simplistic given the scale of the problem, but is there anything everyone could be doing at home to minimise the amount of plastic that makes its way to the oceans?

I think it starts with awareness. Be aware what you do with your used plastics. Don’t just chuck it out. And discuss the issue with your family and friends. I think that a great deal of progress can be made simply by being more careful how we discard our plastic waste.

Imaggeo on Mondays: The road to nowhere – natural hazards in the Peloponnese

Imaggeo on Mondays: The road to nowhere – natural hazards in the Peloponnese

The Gulf of Corinth, in southern Greece, separates the Peloponnese peninsula from the continental mainland. The structural geology of the region is complex, largely defined by the subduction of the African Plate below the Eurasian Plate (a little to the south).

The Gulf itself is an active extensional marine basin, i.e., one that is pulling open and where sediments accumulate. Sedimentary basins result from the thinning, and therefore sinking, of the underlying crust (though other factors can also come into play). The rifting in the region is relatively new, dating back some five million years, and results in rare but dangerous earthquakes.

The active tectonics result in a plethora of other natural hazards, not only earthquakes.  Minor and major faults crisscross the area and have the potential to trigger landslides, posing a threat to lives and infrastructure. A road, swept away in a landslide, in the northern Peloponnese (along the southern margin of the Corinth rift) is a clear example of the hazard.

“This photo was taken in the Valimi fault block [editor’s note: a section of bedrock bound on either side by faults], east of the Krathis valley. West of this valley, the landscape is characterised by  narrow and deep gorges as the present day rivers cut into the well-consolidated conglomerates deposited during the active extension of the basin,” explains Romain Hemelsdaël, author of this week’s imaggeo on Mondays photograph.

Characteristically, sediments deposited in actively extensional rifts where the Earth’s crust and lithosphere are being pulled apart, as at the Gulf of Corinth, change in size (both horizontally and vertically) and composition. To the east of the Krathis valley, the sediments are being uplifted and are dominated by less competent sandstones and siltstones, as opposed to the conglomerates found in the Valimi fault block.

“The present landscape along this part of the rift margin forms large valleys covered by active landslides,” clarifies Romain. “In this photograph, the road was initially constructed directly on silts which were deposited by lakes and rivers. Up the hill, a temporary track currently replaces the road but this track still remains within an active landslide.”

 

Imaggeo is the EGU’s online open access geosciences image repository. All geoscientists (and others) can submit their photographs and videos to this repository and, since it is open access, these images can be used for free by scientists for their presentations or publications, by educators and the general public, and some images can even be used freely for commercial purposes. Photographers also retain full rights of use, as Imaggeo images are licensed and distributed by the EGU under a Creative Commons licence. Submit your photos at http://imaggeo.egu.eu/upload/

What is in your field rucksack? Camping in Iceland

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When you head out into the field, which is the one item you can’t do without? For Rebecca Williams, a volcanologist at the University of Hull, good footwear is essential!

Inspired by a post on Lifehacker on what your average geologist carries in their rucksack/backpack, we’ve put together a few blog posts showcasing what a range of our EGU members carry in their bags whilst in the field!

Beautiful, eyrie, the land where fire meets ice: Iceland. An Earth scientist’ dream, complete with lava, volcanoes, earthquakes, impossible landscapes, ice, snow, the ocean…Iceland, is a top destination for many scientist who want to better understand the processes which shape our planet. Among them, Rebecca Williams, a volcanologist at the University of Hull, who spent a few days camping on the volcanic island this summer.

This bag belongs to: Rebecca Williams, University of Hull.

Field Work location: Þórsmörk, Iceland

Duration of field work: 10 days

What was the aim of the research?: I was working with Dave McGarvie and Jonathan Moles, from the Open University. They are working on a volcano in the area and had come across the Þórsmörk Ignimbrite. Ignimbrites are the deposits from pyroclastic density currents. This unit is quite complicated and not well understood. It is best exposed in Þórsmörk, so we spent 4 days here doing a recce of the exposure in the Þórsmörk area, trying to understand its many facies and their relationship to each other. I then spent the remainder of the time with a field assistant (Steph Walker from Royal Holloway) doing some detailed work on the best exposures, collecting some samples and recording the details of the deposit. We also recce’d some new areas to try to determine the extent of the deposit and finding new localities for future work.

The one item I couldn’t live without:

Footwear! We covered over 10 miles of rough ground and varied terrain each day, so good footwear is essential. I was very thankful for the trekking sandals when fording the rivers. One fording point is on the famous Laugavegur trekking from the hot springs area of Landmannalaugar to the glacial valley of Þórsmörk. We would often see people trying to ford the river in trainers, crocs and even bare feet! It was clear that this wasn’t ideal, and from some of the screeches, very difficult! But in these trekking sandals, I was able to wade over in relative ease and comfort.

Rebecca in the field. Credit: Rebecca Williams

Rebecca in the field. Credit: Rebecca Williams

In the picture of me in the field, you can see what I actually carry when I’m out and about. The zip off trousers were great for fording rivers – I wasn’t expecting it to be hot enough in Iceland to wear them to work! Strapped to my bag are my sandals for fording rivers, and my hammer. The poles were great for getting around on slopes like the one in the background, and for helping out when fording rivers. Here I’m also carrying a spade – acquired once in Iceland. This is unusual for me, I’m used to working with much harder rocks like the welded ignimbrites in Pantelleria. The spade was very useful for digging through scree slopes and material broken up and crushed by glaciers.

 

If you’ve been on field work recently, or work in an industry that requires you to carry equipment, and would like the contents of your bag to feature on the blog, we’d love to hear from you. Please contact the EGU’s Communication Officer, Laura Roberts (networking@egu.eu)

GeoPolicy: Science and the policy cycle

One way to improve the impact of your scientific research is to engage with policy. Doing so can create new opportunities for yourself and your research. The main challenges are knowing when and how to effectively communicate scientific results to policy. If the wrong timing or communication method is chosen then results are less likely to be incorporated into the policy process. This month’s GeoPolicy post takes a look at the policy cycle and how science can be included to strengthen this practice.

 

Why is the policy cycle used?

The policy cycle is an idealised process that explains how policy should be drafted, implemented and assessed. It serves more as an instructive guide for those new to policy rather than a practical strictly-defined process, but many organisations aim to complete policies using the policy cycle as an ideal.

 

Where is science involved?

Science can have a supportive role in every step of the policy cycle. In fact, novel scientific discoveries can sometimes be the instigator to forming new policies. The classic example of this is the ozone hole discovery in 1985 by British Antarctic Survey scientists, Joesph Farman, Brian Gardiner, and Jonathan Shanklin. After a series of rigorous meetings and negotiations by scientists, policy officials, and politicians, the Montreal Protocol on Substances that Deplete the Ozone Layer was signed on 16 September 1987. Without scientific evidence the Montreal Protocol would never have been created.

 

What are the stages of the policy cycle?

The policy cycle is made up of roughly 6 stages and science can be incorporated into every step. How science supports these different stages are described below.

The policy cycle and where scientific advice can be given.

The policy cycle showing where different types of scientific advice can be given. Gif created at http://gifmaker.me/.

 

  • Agenda Setting: This step identifies new issues that may require government action. If multiple areas are identified they all can be assessed, or particular issues may be given a priority.
  • Scientific Input: As described above, new scientific results can be the foundation for forming new policies. Additionally, new focus areas can be anticipated through so-called ‘horizon / foresight scanning’ events that aim to identify emerging issues of policy-relevance.
  • Example: The government may want to increase energy production from renewable sources. This could be through increased solar panel production and usage.

 

  • Formulation: This step defines the structure of the policy. What goals need to be achieved? Will there be additional implications? What will the costs be? How will key stakeholders react to these effects?
  • Scientific Input: Science can be incorporated in this stage through Impact Assessments, which aim to comprehensively assess what effects will occur from a potential policy. These assessments can study multiple strategies to identify the optimum policy.
  • Example: Should governments offer tax-breaks to start-up renewable energy companies? Or should they offer individual subsidies to solar panel buyers? What might be the effects of these actions?

 

  • Adoption: Once the appropriate approval (governmental, legislative, referendum voting etc.) is granted then a policy can be adopted.
  • Science Input: Those in charge of approving a certain policy will often seek external advice that is independent to those who drafted the policy. Scientists can be called upon to offer advice within the decision-making process.
  • Example: A nation-wide policy can be implemented by the national government, but changing a law will require a vote in Parliament.

 

  • Implementation: Establishing that the correct partners have the resources and knowledge to implement the policy. This could involve creating an external organisation to carry out actions. Monitoring to ensure correct policy implementation is also necessary.
  • Scientific Input: Scientific advice can be needed to logistically support the policy being implemented. Scientists can provide methodological guidance to policy workers and advisory bodies who implement the policy.
  • Example: Administration processes to allow organisations and individuals to apply for subsidies / tax benefits need to be created.

 

  • Evaluation: This step assesses the effectiveness and success of the policy. Did any unpredicted effects occur? These assessments can be quantitative and/or qualitative.
  • Scientific Input: Scientists can evaluate the efficiency and effectiveness of policies. This can be done independently or working with policy implementers.
  • Example: The UK and Germany introduced highly popular solar energy policies. Energy production at certain times of the day and year have substantially increased. Occasionally more energy is being produced than is needed, which now leads to further questions about how to handle the ‘excess’ energy.

 

  • Support / Maintenance: This step studies how the policy might be developed, or provides additional support for its continuation. Additionally, the policy can be terminated if deemed redundant, accomplished, or ineffective.
  • Scientific Input: As a policy is continued, scientific advice may be needed on an ad-hoc basis. Updated feedback can be given when needed to help maintain and improve policies.
  • Example: Even if a policy is considered a success, should it be continued? Should solar panel policies be continued, or should policies now focus on improving national electric grids, or should energy storage policies be developed instead?

Remember that scientists should only offer a supportive role to the policy cycle. They should present only the current state of scientific knowledge. Policy officials are the decision makers.

 

Policy cycle shortcomings

The policy cycle has been described as a theoretical concept that it not fully translatable to real world applications. Sometimes, some stages of the cycle are never delivered. Without scientists some of the stages are difficult to accomplish, therefore scientists are in a position to strengthen the policy cycle’s structure through expert advice and assistance.

 

Sources / Further reading

Policy Concepts in 1000 Words: The Policy Cycle and its Stages

GeoPolicy: 8 ways to engage with policy makers 

GeoPolicy: How to communicate science to policy officials – tips and tricks from the experts

The Ozone Hole

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