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  • NATURE PODCAST

How to help feed the world with 'Blue Foods'

Hear the latest science news, with Benjamin Thompson and Shamini Bundell.

In this episode:

00:45 The role of aquatic food in tackling hunger

Ahead of the UN’s Food Systems Summit, Nature journals are publishing research from the Blue Food Assessment, looking at how aquatic foods could help feed the world's population in a healthy, sustainable and equitable way.

We speak to Ismahane Elouafi, Chief Scientist at the Food and Agriculture Organization of the United Nations, who tells us about the role of blue foods in future food systems.

Immersive feature: Blue Foods

Nature's Blue Food collection

12:27 Research Highlights

The ingestible capsule that injects drugs straight into stomach tissue, and a soft material that changes colour when twisted.

Research Highlight: An easily swallowed capsule injects drugs straight into the gut

Research Highlight: Flowing crystals for quick camouflage

14:52 How Australian wildfires spurred phytoplankton blooms

The devastating Australian wildfires of 2019-2020 released plumes of iron-rich aerosols that circled the globe, fertilizing oceans thousands of miles away. New research suggests that these aerosols ultimately triggered blooms of microscopic phytoplankton downwind of the fires, in the Southern Ocean.

Research Article: Tang et al.

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doi: https://doi.org/10.1038/d41586-021-02467-w

Transcript

Hear the latest science news, with Benjamin Thompson and Shamini Bundell.

Host: Benjamin Thompson

Welcome back to the Nature Podcast. This week, how foods grown in water could help feed the world.

Host: Shamini Bundell

And how wildfires in Australia affected phytoplankton growth thousands of kilometres away. I’m Shamini Bundell.

Host: Benjamin Thompson

And I’m Benjamin Thompson.

[Jingle]

Host: Benjamin Thompson

Next week is the United Nations’ Food Systems Summit. This is a global meeting of heads of state and other key stakeholders, which aims to bring about changes to the world’s food production systems to help meet the UN’s Sustainable Development Goals. This project looks at so-called ‘blue foods’, things like plants, animals and algae from freshwater and marine environments. It explores the role that they could play in feeding the world's population in a healthy, sustainable and equitable way over the coming decades. To find out more about the role of blue foods in future food systems, Nature’s editor-in-chief Magdalena Skipper spoke with Ismahane Elouafi, chief scientist at the Food and Agriculture Organization of the United Nations, better known as the FAO. Here’s Magdalena.

Interviewer: Magdalena Skipper

I’m really delighted, Ismahane, that you’ve agreed to join me for this conversation, not least because 2021 is of course a really important year for the food systems. Could you give us a sense of the global problem with the current food system and how can blue food provide a solution or contribute to the solution?

Interviewee: Ismahane Elouafi

I think that when we talk about food security and nutrition security, we don’t need to define it any more. We know very well that we are losing ground. Now we know that we have 811 million people that are facing hunger, and the numbers have not reduced. They are growing by the day, and that’s where, if we can find systems that are producing more nutritious foods that are more environmental for the population on this planet Earth, this is a must. We have to invest in it. And that’s where blue foods are very important, to really provide us with more nutrition and more food for this growing population.

Interviewer: Magdalena Skipper

To many, when we think about food production, we predominately associate that with land-based production. We know that blue foods are connected with the rest of the food system, and yet policies that govern aquatic and terrestrial food production are largely siloed. Do you anticipate this to change?

Interviewee: Ismahane Elouafi

It has to change because we finally are looking at the whole food system, so I think it is needed. It’s a bit more complex than terrestrial production because of the geographic spreading of oceans, of fish, of algae and aquatic plants. That’s a complexity that we have to find a way around, to assess it, protect it and manage it properly. But there is also, I think, more and more interest in understanding how could we produce more. So, there is many areas that could be developed, and it has to be tackled. As the population is growing and as we are not able to produce more on the Earth per se, but rather we’re going to be producing less because of the climate change, because of the heating, then the pressure on food and nutrition coming from the blue food is rising quite a lot.

Interviewer: Magdalena Skipper

So, you, very appropriately, wove into the discussion, the issue of climate change. More broadly, of course, one cannot talk about food production without thinking about its environmental impact. One of the Blue Food Assessment papers, and of course many other publications also, evaluate this environmental impact for aquatic foods in particular and identifies opportunities for directing policies towards supporting particular aquatic food types that minimise environmental impact. These recommendations, though, are of course based on models. Can you comment on how useful modelling like this is?

Interviewee: Ismahane Elouafi

So, modelling is very important, and your model is as good as what databases you have developed and what information you’ve got in so the more data we have, the better our outcomes are closer to the reality. Over the last 20 years, there is more and more interest on carbon footprint, and good assessment of carbon footprint in blue food or plant-based or terrestrial animals, and that’s where it’s very important that we identify alternatives that are less pollutant, and we need really to develop policies and regulations and incentives around those low-carbon or zero-carbon options. So, this applies as well in the blue food, and if we target it and if we tackle it and provide alternatives, it’s very important for us to go ahead with it and scale it up to have the impact that we need to do before 2030 agenda, before 2050 where we have lots of very bad scenarios by 2050 by the IPCC report.

Interviewer: Magdalena Skipper

Let’s talk about demand for particular types of food. So, there is, in fact, data from the FAO as well as the World Bank suggesting, in fact strongly indicating, that there is a steady growth in demand for aquatic foods. Should we in fact work towards enhancing that demand and if so, what do you envision are the best strategies for directing these diet requirements globally?

Interviewee: Ismahane Elouafi

So, for me, the demand will grow, whether we are pushing for it or not, and the reason behind it is that the population is growing, so the demand for food in general is growing. We have also economic developments in certain countries that will boost more consumption in those countries. And blue food is, how would I call it, it’s growing in interest. The more we know about the nutritious values of the blue food, the more we’re going to have a demand for it. So, it’s not a matter of if it’s the right thing to do or not, but this is happening. And the ecosystems where we have the blue foods are very fragile ecosystems because of climate change and because of the pollutants, so it’s very important for us to manage it properly to make sure we are building a more resilient system, more sustainable, more inclusive and more equitable.

Interviewer: Magdalena Skipper

Speaking of being inclusive, both the blue food and terrestrial food production, much of it, of course, is in the hands of small-scale producers, and generally, historically, under-appreciated constituencies, so just for example women, play a really important function in generating food for many communities. Do you think that we are making the most of their contributions to engineering, to reimagining of the food system, both from their perspective but also indeed from the perspective of is the food system transformation being done the right way?

Interviewee: Ismahane Elouafi

The short answer, Magdalena, is no. Most of the solutions that were created over the last 50 years never made it to the farmers because most of those farmers are smallholders and because most of the solutions were not created for them. It was much more created for larger, commercial farming systems in general. So, we have really to look at what smallholders need and provide them with those solutions, and that’s part of the deep transformation that we need in our food systems. The other area is the gender, per se. Really, how could we work more with women? How could we provide them with the right solutions that works better for their ecosystems, for their communities, for their production systems? The third component that I think is really, very, very interesting, and that I have to say that the UN Food Systems Summit is trying to address, it’s really the youth and how can we provide a voice to the youth and bring them on board? How can we excite them again about the agri-food systems because, in most of the least- and middle-income countries, agriculture is not appealing to most of the youth because it’s not like agriculture at large, including fisheries in the OECD countries. It’s very traditional. It’s not encompassing enough innovation because of the cost, so if we want to really bring youth back to agriculture, we need to modernise it and modernise it in a way that works for smallholders in least- and middle-income countries.

Interviewer: Magdalena Skipper

So, there is a lot of momentum towards food system transformation. Already this year we’ve seen a lot of preparation, for example, towards the Food Systems Summit. What’s the prospects for the future? How quickly can we transform the food systems? When can we reach food security on a global scale?

Interviewee: Ismahane Elouafi

That’s a difficult question, sincerely, Magdalena, because, see, we had a plan. Since 2015, we had the 2030 development agenda, and we had really, very clear targets there, that hopefully we will end hunger, poverty and many other things by 2030. What we know right now is that we are not on track, but the bright side of it is that, in my mind, there is so many low-hanging fruit that will require a coalition of willing governments and stakeholders to make it happen. Like if we can only thing about waste and loss, we have about more than 34% of our food, from the blue food to others, that are wasted or lost. There is huge pollution that really is affecting the blue food production and the quality of the food, per se. That could be also quite easy to manage through the proper policies, through the proper guidelines, the proper reforms and the proper incentives as well. There is many things that could be done if we are really taking a global action. In a nutshell, it’s very hard to give a year. We all we’re aiming for 2030, but in the same time, there is many things that we could do to speed up the process. I will hope really that the Food Systems Summit will allow us to identify and to bring in all the stakeholders to have a true transformation that will allow us to at least stay within the targets of 2030.

Host: Benjamin Thompson

That was Ismahane Elouafi, chief scientist for the FAO. To find out more about the Blue Food Assessment and to read the research papers, the associated Comment articles and an editorial, look out for a link in this week’s show notes.

Host: Shamini Bundell

Coming up, we’ll be hearing more about the world’s oceans and how Australia’s recent wildfires affected the growth of marine phytoplankton. Before that, though, Dan Fox is here with this week’s Research Highlights.

[Jingle]

Dan Fox

Are you squeamish about syringes? Nervous about needles? If so, you’re not alone. Many people around the world are, which can be problematic if you need to receive one of the many medications that are only effective when delivered by injection. To overcome this issue, researchers have come up with a new design that combines the function of an injection in the form of a pill that can be swallowed. The team’s egg-shaped capsule is 15 millimetres tall and can hold 4 milligrams of a liquid drug. When swallowed, it settles in the stomach and, thanks to a weighted bottom, automatically rights itself. Digestive fluids then dissolve a pellet at the top of the capsule, triggering a needle to inject a medicine into the stomach wall. The needle then retracts so the device can pass safely through the intestines. The team have shown their pill can administer pharmaceuticals, such as insulin, to animals, and hope to test the auto-injector capsule in humans soon. Take your time to digest that research in Nature Biotechnology.

Dan Fox

Octopuses can manipulate the colour of individual pixel-like cells in their skin, allowing the animals to match their surroundings at will. Now, researchers have developed a similarly controllable colour changing material in the lab using liquid crystals. The team created a soft film of long, liquid crystal molecules that reflect different colours depending on how tightly they are twisted. They then set this film atop a flat platform containing an array of microscopic air chambers. These chambers serve as the pixels, inflating and deflating, deforming the film and changing its colour. The system can reproduce colourful patterns on command, allowing the film to blend in to a complex background. The film also reflects infrared light, which could allow of the creation of thermal images invisible to the naked eye. Read the full paper, if you can find it, in Nature Materials.

[Jingle]

Host: Shamini Bundell

The Australian summer of 2019-2020 was devastating for wildfires. It was one of the most severe seasons in the country’s history. Millions of hectares of land were burned, nearly 3 billion animals may have died, and it’s estimated that over 700 million tons of carbon dioxide were emitted into the atmosphere. But this week in Nature, researchers have published evidence of another impact of these fires, and it’s one that you might not expect. We heard earlier about how fragile marine ecosystems are, and this work describes how aerosols released during the fires travelled thousands of kilometres and landed in the oceans, where they may have triggered blooms of microscopic phytoplankton. To find out more, Anand Jagatia spoke to the joint first authors, Weiyi Tang from Princeton University in the US and Joan Llort from the Barcelona Supercomputing Center in Spain. He started by asking Weiyi how aerosols from fire could affect marine life.

Interviewee: Weiyi Tang

Previous studies have measures of nutrients contained in aerosols. So, they found aerosols could be enriched in macronutrients and trace metals, including iron. So, those elements are essential to life, including for phytoplankton in the ocean. So, that leads us to think about whether those aerosols emitted from the Australian wildfires could affect the marine ecosystem.

Interviewer: Anand Jagatia

Okay, and Joan, I’m going to bring you in here, when you were looking at these aerosols, what kinds of data were you actually taking into account? How were you able to see where they travelled from where they originated to where they ended up?

Interviewee: Joan Llort

So, we get different sources of data, so there’s some satellites that have some sensors to estimate the quantity of aerosols in the atmosphere to see where the smoke was going. So, the fire started on the southeastern coast of Australia, and the prevailing winds in the region transported all the smoke towards the east, reaching the Pacific Ocean. The smoke reached South America and even it went all through the Atlantic and Indian Oceans. So, it’s mesmerising because you can see these plumes of smoke travelling around the globe, and it has been shown that it went into the stratosphere. It modified the circulation of the atmosphere. And it actually kind of reduced the amount of heat that the Earth was absorbing this year.

Interviewer: Anand Jagatia

And you were also interested in figuring out what was in the aerosols, particularly looking for the presence of iron. Why were you so interested in iron?

Interviewee: Joan Llort

We knew that these waters in the Southern Ocean were limited in iron, and there has been lots of research proposing that if we add iron into the Southern Ocean, we will fertilise this water. So, the question was did these aerosols contain any iron at all? In the small island of Tasmania, south of Australia, they have a sampling station for aerosols, and we actually found that when the smoke was coming from the fires, there was lots of iron concentration in our sampling station.

Interviewer: Anand Jagatia

And then what were you looking for in terms of the impact that these aerosols might have had when they landed in the oceans?

Interviewee: Joan Llort

So, we knew there was smoke in the atmosphere, but this doesn’t give you any information of if this smoke and aerosols are going into the ocean because we also knew that it was reaching the stratosphere, so it could just stay there forever. So, what we need for that is we need two things. First one was to look at another satellite data that gives us information about the phytoplankton concentration at the surface of the ocean, and we found that there was an anomalous response of phytoplankton. And the other thing we got is that there’s some robot in the ocean right now that has been deployed for more than ten years now, and they sample the ocean, and every ten days they come to the surface and they send us the data through satellite. We were lucky enough that a couple of robots were in the region where we observed anomalous phytoplankton concentration, so we could infer that actually there was a response related to the passage of the smoke.

Interviewer: Anand Jagatia

So, you were able to show that the aerosols did get into the water and that they had an effect on the phytoplankton creating this anomalous concentration, as you referred to it. Weiyi, what did you actually see? What do you mean by that?

Interviewee: Weiyi Tang

In our study region in the deep ocean in the south Pacific and Southern Ocean, we observed strong response of phytoplankton. Some of those regions doubled the phytoplankton biomass concentration or even more.

Interviewer: Anand Jagatia

How confident can you be that it was the fires that triggered the bloom?

Interviewee: Weiyi Tang

So, there are other sources of nutrients that potentially affected the phytoplankton bloom in the Southern Ocean, like transport of the nutrients from other regions and mixing of the deep water that are enriched in nutrients to the surface, so we have estimates the potential impact of those other nutrient sources, and we found that those impacts might be relatively small compared to the impact from the aerosols.

Interviewer: Anand Jagatia

And Joan, were you surprised by what you found? I mean, it is kind of mind-blowing that wildfires can potentially impact marine ecosystems that are so far away.

Interviewee: Joan Llort

Well, for me, there is a beautiful idea of the natural cycles tend to recycle anything. The idea that two different ecosystems that are like 10,000 kilometres away are connected, and what’s going on in one ecosystem is affecting the other one, for me, it’s a pretty amazing idea. This is why it’s so important to study iron and any kind of aerosols that bring iron into the Southern Ocean waters because we know that you can even modify the carbon cycle at the global scale.

Interviewer: Anand Jagatia

It sounds like there’s actually quite a complex set of interactions going on here, that you’ve potentially got climate change, which is leading to more wildfires, which could potentially affect marine ecosystems, and then that in turn is going to impact the climate and have a further impact on wildfires.

Interviewee: Joan Llort

Yeah, you’re absolutely right because the phytoplankton is like any plant that we have at home. It absorbs CO2 and it produces oxygen during photosynthesis. The difficult thing to know here is why the phytoplankton has absorbed this carbon and has metabolised it. This carbon, it stays in the surface and goes again into the atmosphere or it goes into the deep ocean. If it goes into the deep ocean then it means that you’re sequestering this carbon for hundreds of years or thousands of years. But if it stays in the surface then it doesn’t change anything, and that’s a big knowledge gap right now.

Host: Shamini Bundell

That was Joan Llort speaking to Anand Jagatia. You also heard from Weiyi Tang. You can find a link to their paper in the show notes.

Host: Benjamin Thompson

And that’s all we’ve got time for on this week’s show. Join us again next time for more stories from the world of science. And don’t forget that in the meantime, you can drop us a line, either on Twitter – @NaturePodcast – or email – podcast@nature.com I’m Benjamin Thompson.

Host: Shamini Bundell

And I’m Shamini Bundell. Thanks for listening.

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