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Professor Jenny Clack, FRS, 1947-2020

News from this site - Thu, 26/03/2020 - 14:16

clack_prof_jenny_hres.jpg We are very sad to announce the death of our colleague Jenny Clack. Jenny died peacefully at home. Jenny joined the Museum and Department as an Assistant Curator in 1981. She subsequently obtained her PhD in 1984. The University's arcane regulations meant that Jenny was an assistant curator for...

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The world's their fish finger

Cam ac uk zoology department feed - Thu, 12/03/2020 - 14:07
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fish finger

Smothered in ketchup or squished into a sandwich, there’s one tasty convenience food that’s hard to resist. With over 1.5 million of them eaten every day in Britain, fish fingers are one of the nation’s favourite foods. Now two Cambridge researchers believe that a twist on this 1950’s creation might help address the challenge of sustainably feeding our global population.

David Willer and Dr David Aldridge are on a mission to work out how to look after our planet and people’s health at the same time. Zoologists in the University of Cambridge Conservation Research Institute, they want to demonstrate that bivalve shellfish – oysters, scallops, mussels and clams – can be a source of affordable, sustainable and nutritious food.

“In the developed world, over two billion people eat too many calories but not enough nutrients to stay healthy,” says Willer, “and a billion people in the developing world don’t have access to enough food. We believe bivalves are the answer!”

Better for the planet

“This is about providing people with food that is environmentally sustainable but also nutrient dense,” says Willer. “We know that meat and fish have a greater environmental impact than plant-based foods. But the environmental footprint of bivalve aquaculture is even lower than many arable crops in terms of greenhouse gas emissions, land and freshwater use.”

Bivalves sit right at the bottom of the food chain. They are filter feeders, and eat whatever is suspended in the water, which is usually either decaying organic matter or algae. This is in stark contrast to salmon farming, which takes five kilos of wild fish for every kilo of salmon produced. Willer says that if just 25% of this ‘carnivorous fish’ aquaculture was replaced with an equivalent quantity of protein from bivalve aquaculture, 16.3 million tonnes of CO2 emissions could be saved annually – equivalent to half the annual emissions of New Zealand.

Bivalves offer other environmental benefits too. Farming them has many benefits on marine ecosystems including the provision of nursery habitats for fish, coastal protection, and helping to clean up waterways by filtering out nuisance algae and suspended sediments.  

Room to grow

Across the world there is a huge area of coastline suitable for growing bivalve shellfish – an estimated 1,500,000 square kilometres, equivalent to over six times the total area of the United Kingdom. Willer says that developing just one percent of this could produce enough bivalves to fulfil the protein requirements of over one billion people.

“The regions of the world where there’s a lot of available coastline include places where people need extra sources of protein in their diets, such as the west coast of Africa, and Asia,” says Willer. In developing countries like these, where populations are growing, there are high levels of malnutrition because people are not getting the key nutrients and the energy they need from traditional diets.

Bivalves have a higher protein content (per kcal) than beef. They are high in many key nutrients that humans need, including vitamin A, iodine and zinc, and omega-3 fatty acids. A small quantity eaten regularly is a far more efficient way of getting required levels of these nutrients compared with eating a large variety of plant crops, all of which require land and resources to produce.

The safety issue

The challenge for the researchers is to increase the productivity of bivalve farming, while at the same time raising safety standards. Their work focuses on oysters and other bivalves at the hatchery stage, where they are grown for a year before being put into open sea – on ropes or in cages – to grow to full size.

“At the moment, bivalve hatcheries are very small scale and pretty basic,” says Willer. “Farmers grow algae to feed the oysters in big tanks using lots of light and energy. The tanks get contaminated all the time, so a lot of the feed is bad quality or gets wasted. This is the main cause of bacterial disease in shellfish. For a farmer working alone, it’s a difficult venture.”

One of the reasons why some people won’t eat mussels, oysters and other bivalves is fear of food poisoning – of which there have been some high profile cases, including a recent gastroenteritis epidemic in Brittany. Oysters in particular tend to be eaten raw, so anything harmful within them – most commonly norovirus – is not killed before they’re consumed by humans.

Taking control

Willer and Aldridge’s solution is to change the bivalve feed. They have developed a specially formulated diet for the shellfish that enables farmers to take better control of their hatcheries.

“We call it a ‘microencapsulated BioBullet’,” says Aldridge. “It contains algae, just like the algae being used in the hatcheries now, except ours is grown on a commercial scale and then powdered down and sterilised. As well as preventing the introduction of diseases into hatcheries, our new method is about 100 times more efficient than the current one in terms of energy use, carbon emissions and cost.”

The fact that the algae is sourced from the waste streams of other aquaculture systems gives this method an additional environmentally friendly credential. The approach has attracted funding from European Institute of Innovation and Technology’s Food programme (EIT Food) – an initiative working to make the food system more sustainable, healthy and trusted.

Microencapsulation involves putting the powdered algae inside a type of miniature eggshell made from vegetable oil, and adding a coating to make it buoyant and palatable. Other nutrients can be added as required, to alter the nutritional value or even palatability to the shellfish and ultimately the dietary benefits to human consumers.

This creates the potential to address particular nutrient deficiencies in a consumer population. Any nutrient or vitamin is far more easily absorbed by the body when it is integrated into a protein and fat source, rather than being in supplement form.

When bivalves are harvested they are held in tanks for a week before being sent to market. Clean water is run through the tanks to flush out the contents of their guts. At this stage, anything fed to the shellfish will remain in their gut cavity and be eaten by the consumer.

“The additives are where things get really interesting,” says Willer. “One of the unique things about shellfish is that when you eat one, you eat the entire organism – including the gut. The microencapsulated diet allows either a flavouring or nutrient to be delivered at the final stage of shellfish production so it stays within the bivalve when it’s harvested.”

Oyster hatchery. Credit: University of Maryland Center for Environmental Science on Flickr

Oyster hatchery. Credit: University of Maryland Center for Environmental Science on Flickr

The microencapsulated BioBullets. Credit: David Willer.

The microencapsulated BioBullets. Credit: David Willer.

Magnification of the microencapsulated BioBullets. Each particle is less than 100µm in diameter.

Magnification of the microencapsulated BioBullets. Each particle is less than 100µm in diameter.

Oyster in a clean water tank. Credit: Oregon State University on Flickr.

Oyster in a clean water tank. Credit: Oregon State University on Flickr.

Commercial development

Willer and Aldridge have been collaborating closely with a shellfish company in Whitstable, Kent – a town defined by the oysters it has produced since Roman times – to develop their microencapsulated diet into a saleable product. In addition, Aldridge and another team member, Dr Camilla Campanati, have tested products in commercial settings in Spain, achieving remarkable results.

“Mediterranean mussel spat reared on our BioBullets grew just as fast and survived just as well as mussels fed with the leading commercial alternative, an algal concentrate,” says Aldridge, “but our products cost ten times less than this alternative and are much easier to handle and store.” The results of an independent consumer panel are very encouraging too: mussels fed on BioBullets were deemed just as tasty and attractive as mussels produced by conventional methods.

“It’s surprising how little research has been done on this,” says Willer. “A few people tried to make a type of microencapsulated feed in the 1980s but it didn’t work, partly because the technology wasn’t available. We hope that with the recent successful trials of our new forms of microencapsulated diets, and continued refinement, it won’t be long before the concept goes mainstream and drives the expansion of the bivalve industry on a huge scale.”

The final hurdle

There is just one last challenge to overcome before bivalves could help to feed the world. “They’re not actually a food many people tend to like,” admits Willer, “and I think that’s probably one of the biggest challenges. We can increase the production of a very sustainable food, but if no-one eats it, it’s pointless.”

Diets have changed a lot since the 19th century when oysters in Britain were cheap and eaten in large quantities, mostly by the poorest in society. Today, oysters and other bivalve shellfish are perceived as luxury foods in the Western world – but only by those who relish the salty, slippery sensation of slurping them down.

Rather than trying to convince the rest of us to change our dietary preferences, Willer and Aldridge are looking at novel ways to make bivalves more palatable – essentially by disguising them. One idea is to swap out fish – which is often sourced unsustainably – for processed clam meat in a new form of ‘bivalve fishfinger.”

“Climate change is an impending pressure, and this pressure extends to our food supply,” says Aldridge. “We need to make fairly rapid changes to people’s diets, and trying to encourage huge cultural shifts just isn’t going to work. I think modifying things people are familiar with is the best way to make bivalves into a more acceptable product.” Microencapsulated diets really could be the start of a revolution. 

This research is funded by a BBSRC studentship to David Willer, the EIT Food Project MIDSA to David Aldridge, and BioBullets Ltd.

Additional photo credits (top to bottom): Fish fingers (anon); Clams by Andrew Yee on Flickr; Mussels by fancyday on Pixabay; Coastline in Senegal by Peter Harrison on Flickr; Whitstable by Mariuz Kluzniak on Flickr and by Judith on Flickr; Mussels by G. Morel on Flickr; Plate of oysters by Jameson Fink on Flickr; Oysters by Jean Louis Tosque on Pixabay.

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Smothered in ketchup or squished into a sandwich, there’s one tasty convenience food that’s hard to resist. Now two Cambridge researchers believe that a twist on the classic fish finger might help address the challenge of sustainably feeding our global population.

Image: Affiliation (schools and institutions): School of the Biological SciencesDepartment of ZoologyUniversity of Cambridge Conservation Research Institute (UCCRI)People (our academics and staff): David AldridgeDavid WillerSubject (including Spotlight on ... where applicable): Sustainable EarthGlobal food securityfishStoriesSection: ResearchNews type: Features
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Alarm! Quick, move! And stay hidden.

News from this site - Thu, 20/02/2020 - 08:45

In the struggle between predators and prey, a split-second can separate the quick from the dead. Alarm calls warning of immediate danger must, therefore, send rapid messages, yet animals often signal more urgent danger using repeated notes. This is paradoxical because more notes take more time to deliver. New Holland...

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Watching TV helps birds make better food choices

Cam ac uk zoology department feed - Thu, 20/02/2020 - 05:01

Seeing the ‘disgust response’ in others helps them recognise distasteful prey by their conspicuous markings without having to taste them, and this can potentially increase both the birds’ and their prey’s survival rate. 

The study, published in the Journal of Animal Ecology, showed that blue tits (Cyanistes caeruleus) learned best by watching their own species, whereas great tits (Parus major) learned just as well from great tits and blue tits. In addition to learning directly from trial and error, birds can decrease the likelihood of bad experiences - and potential poisoning - by watching others. Such social transmission of information about novel prey could have significant effects on prey evolution, and help explain why different bird species flock together.

“Blue tits and great tits forage together and have a similar diet, but they may differ in their hesitation to try novel food. By watching others, they can learn quickly and safely which prey are best to eat. This can reduce the time and energy they invest in trying different prey, and also help them avoid the ill effects of eating toxic prey,” said Liisa Hämäläinen, formerly a PhD student in the University of Cambridge’s Department of Zoology (now at Macquarie University, Sydney) and first author of the report.

This is the first study to show that blue tits are just as good as great tits at learning by observing others. Previously, scientists thought great tits were better, but had only looked at learning about tasty foods. This new work shows that using social information to avoid bad outcomes is especially important in nature. 

Many insect species, such as ladybirds, firebugs and tiger moths have developed conspicuous markings and bitter-tasting chemical defences to deter predators. But before birds learn to associate the markings with a disgusting taste, these species are at high risk of being eaten because they stand out. 

“Conspicuous warning colours are an effective anti-predator defence for insects, but only after predators have learnt to associate the warning signal with a disgusting taste,” said Hämäläinen. “Before that, these insects are an easy target for naive, uneducated predators.” 

Blue tits and great tits forage together in the wild, so have many opportunities to learn from each other. If prey avoidance behaviour spreads quickly through predator populations, this could benefit the ongoing survival of the prey species significantly, and help drive its evolution.

The researchers showed each bird a video of another bird’s response as it ate a disgusting prey item. The TV bird’s disgust response to unpalatable food - including vigorous beak wiping and head shaking - provided information for the watching bird. The use of video allowed complete control of the information each bird saw.

The ‘prey’ shown on TV consisted of small pieces of almond flakes glued inside a white paper packet. In some of the packets, the almond flakes had been soaked in a bitter-tasting solution. Two black symbols printed on the outsides of the packets indicated palatability: tasty ‘prey’ had a cross symbol that blended into the background, and disgusting ‘prey’ had a conspicuous square symbol.

The TV-watching birds were then presented with the different novel ‘prey’ that was either tasty or disgusting, to see if they had learned from the birds on the TV. Both blue tits and great tits ate fewer of the disgusting ‘prey’ packets after watching the bird on TV showing a disgust response to those packets.

Birds, and all other predators, have to work out whether a potential food is worth eating in terms of benefits – such as nutrient content, and costs – such as the level of toxic defence chemicals. Watching others can influence their food preferences and help them learn to avoid unpalatable foods.

“In our previous work using great tits as a ‘model predator’, we found that if one bird sees another being repulsed by a new type of prey, then both birds learn to avoid it in the future. By extending the research we now see that different bird species can learn from each other too,” said Dr Rose Thorogood, previously at the University of Cambridge’s Department of Zoology and now at the University of Helsinki’s HiLIFE Institute of Life Science in Finland, who led the research. “This increases the potential audience that can learn by watching others, and helps to drive the evolution of the prey species.”

This research was funded by the Natural Environment Research Council UK and the Finnish Cultural Foundation.

Reference
Hämäläinen, L. et al, ‘Social learning within and across predator species reduces attacks on novel aposematic prey’, Jan 2020, Journal of Animal Ecology. DOI: 10.1111/1365-2656.13180 

By watching videos of each other eating, blue tits and great tits can learn to avoid foods that taste disgusting and are potentially toxic, a new study has found.

By watching others, blue tits and great tits can learn quickly and safely which prey are best to eat.Liisa HämäläinenNataba, Adobe Stock imagesGreat tit and blue tit. Credit: Nataba, Adobe Stock images


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Vomiting bumblebees show that sweeter is not necessarily better

Cam ac uk zoology department feed - Wed, 22/01/2020 - 00:01

Bumblebees drink nectar from flowers, then offload it in their nest – by vomiting –  for use by other bees in the colony. The sugar within nectar makes it appealing, and the more sugar within the nectar, the more energy it contains. But nectar also gets more thick and sticky as the sugar content rises, and this makes it more difficult for bees to drink and regurgitate –  requiring more time and energy. 

Published today in the Journal of the Royal Society Interface, the study looked at the mechanics of both nectar drinking and regurgitation in one of the most common bumblebees in the UK, Bombus terrestris. It found that the best concentration of nectar for bumblebees in terms of overall energy gain is lower than might be expected. Nectar that is low in sugar is easy for bees to drink and very easy to vomit back up. As nectar gets more sugary, it gradually takes bees longer to drink, but swiftly becomes much more difficult to vomit. 

“Bumblebees must strike a balance between choosing a nectar that is energy-rich, but isn’t too time-consuming to drink and offload. Nectar sugar concentration affects the speed of the bees’ foraging trips, so it influences their foraging decisions,” said Dr Jonathan Pattrick, first author of this study, formerly a PhD student based jointly in the University of Cambridge’s departments of Plant Sciences and Zoology and now a post-doctoral researcher in the University of Oxford’s Department of Zoology. 

While it has long been known that nectar with a higher sugar concentration takes bees longer to drink, its effect on nectar regurgitation has not previously received much attention. This new information will help scientists make better predictions about which types of nectar bumblebees and other pollinators should like best, and consequently the kinds of flowers and plants they are most likely to visit. This will inform crop breeders in producing the most appealing flowers for better crop pollination and higher yields. 

To conduct the research, bees were allowed to forage on sugar solutions of three different concentrations in the Department of Plant Science’s Bee Lab. While doing this, the bees were also timed and weighed. When the bees returned to their ‘nest’, the researchers watched them through a Perspex lid, timing how long it took for the bees to vomit up the nectar they had collected.

“For low strength nectar, bees had a quick vomit that only lasted a few seconds, then were back out and foraging again,” said Pattrick, “but for really thick nectar they took ages to vomit, sometimes straining for nearly a minute.” 

For any given nectar concentration, bees regurgitate the nectar quicker than they initially drink it. But as nectar sugar concentration –  and therefore stickiness –  goes up, the rate of regurgitation decreases faster than the rate of drinking. “It’s hard to drink a thick, sticky liquid, but imagine trying to spit it out again through a straw – that would be even harder,” said Pattrick. “At a certain sugar concentration, the energy gain versus energy loss is optimised for nectar feeders.”

The perfect nectar sugar concentration for the highest energy intake depends on the species drinking it, because different species feed in different ways. Bumblebees and honeybees feed by dipping their tongue repeatedly into the nectar, but regurgitate by forcing the nectar back up through a tube – just like when humans are sick. Other species such as Orchid Bees suck nectar up instead of lapping it, so struggle even more when nectar is highly concentrated. This influences nectar preference and the plants visited by different species.

Current crop breeding is focused on enhancing traits like yield and disease resistance, rather than considering pollinator preference. The new results improve predictions of the perfect nectar concentration for making the most efficient use of pollinating bumblebees.

Nectar is produced by flowers to attract pollinators, and a source of food for many species of insect, bird and mammal. The levels of the sugars sucrose, glucose and fructose within the nectar vary depending on the plant producing it.

“Studies have shown that numbers of some pollinators are going down, but there are more and more people in the world to feed. We need to make better use of the pollinators we have,” said Professor Beverley Glover in Cambridge’s Department of Plant Sciences and Director of Cambridge University Botanic Garden, who led the study. “This research will help us understand the types of flowers and plants the bees are most likely to visit, which will inform crop breeding to make the best use of the available pollinators.”

This research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).

Reference
Pattrick, J.G. et al. ‘The mechanics of nectar offloading in the bumblebee Bombus terrestris and implications for optimal concentrations during nectar foraging.’ Interface, Jan 2020. DOI: 10.1098/rsif.2019.0632

Animal pollinators support the production of three-quarters of the world’s food crops, and many flowers produce nectar to reward the pollinators. A new study using bumblebees has found that the sweetest nectar is not necessarily the best: too much sugar slows down the bees. The results will inform breeding efforts to make crops more attractive to pollinators, boosting yields to feed our growing global population.

With really thick nectar the bees took ages to vomit, sometimes straining for nearly a minuteJonathan PattrickYani Dubin on FlickrBumblebee, Bombus terrestrisImproving flowers to help feed the world

A rising world population means we’ll need more food in the coming years. But much of our food relies on insect pollination, and insects are in decline around the world. Can we make flowers better at being pollinated, to help solve this problem?

 

This film was funded by EIT Food, as part of the #AnnualFoodAgenda project.


The text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright ©University of Cambridge and licensors/contributors as identified.  All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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The 'P' word

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It's time for blue-sky thinking plus practical measures in the battle to reduce plastic waste.

In Tokyo, a householder consults her 60-page ‘Garbage Separation and Disposal’ system to check whether it's a recycle day for plastic bottles or for all other plastic packaging.

In a coastal village in Kenya, an order has been received for 2,000 bricks made from waste plastic and earth.

On a chemistry bench in Cambridge, bubbles of hydrogen form and rise around a thumbnail-sized square of plastic cut from a water bottle.

All around the world there are instances where we are getting things right with plastic – recycling, recovering, re-using – and instances where we are getting things very wrong.

Our awareness of just how wrong is riding the crest of a plastic-polluted wave: every year, more than 8 million tonnes of plastic waste ends up in the world’s oceans. Environmental agencies have predicted that if these trends continue, our oceans will contain more plastic than fish by 2050.

Plastic has become a malevolent symbol of our wasteful society. But it's also one of the most successful materials ever invented: it’s cheap, durable, flexible, waterproof, versatile and lightweight. It’s fundamental to almost every aspect of our lives and it's a resource that we are wasting, says Professor Erwin Reisner.

“As a chemist I look at plastic and I see an extremely useful material that is rich in chemicals and energy – a material that shouldn’t end up in landfills and pollute the environment. Plastic is an example of how we must find ways to use resources without irreversibly changing the planet for future generations.”

Reisner leads Cambridge University's new Cambridge Creative Circular Plastics Centre (CirPlas). Funded by UK Research and Innovation, it aims to eliminate plastic waste by combining blue-sky thinking with practical measures, connecting expertise across the disciplines, and collaborating with industry and local government.

In doing so, their research reaches from the Tokyo householder to the Kenyan brickmaker to the Cambridge chemist, and yet further still.

How do we keep track of plastic?

Ask anyone what they know about plastic and they might tell you about the need to ban single-use materials, or that it’s essential for healthcare, or that it’s lighter and more fuel efficient than packaging alternatives.

“What no-one will tell you is how any of this relates to how much and what type of plastic we use, how long those products are in service, and what happens to them afterwards. The fact is – no-one knows,” says Dr Andre Serrenho.

It seems a simple enough set of questions but the data is complex and held by many different bodies. And so, as part of CirPlas, he and Dr Jonathan Cullen in the Department of Engineering are creating a map of the flow of plastic in the UK economy by amassing all of this data in one place.

Meanwhile, engineer Dr Ronan Daly is exploring digitally enabled solutions to label and track plastic, and zoologist Dr David Aldridge is using sensing technologies to measure how much microplastic is entering the food chain.

“All of these studies will take us closer to answering something we’ve never been able to answer before,” adds Serrenho. “Plastic helps us live safer, more convenient lives but how much is enough plastic and how much is too much?”

Zero waste from industry

One area where plastic has transformed modern-day living is in food safety. Of the 5 million tonnes of plastic used each year by the UK, 37% is used for packaging, of which almost three-quarters is for soft drinks. The challenges presented by waste from this packaging cannot be ignored, least of all by the industries that depend on it.

“What’s needed now is collective and informed action from individuals, government and business to shift us back in the right direction,” says Beverley Cornaby.

Last year, she and colleagues at the Cambridge Institute for Sustainability Leadership worked with 10 of the UK’s largest bottled drinks companies to understand what this collective action might look like. The result was an ambitious roadmap for zero plastic packaging waste from the industry being sent to landfill or escaping into the natural landscape by 2030.

“One of the areas we identified was around design. Businesses can sometimes move faster than government policy and so making changes to their own products can provide quicker fixes,” she adds.

“We’ve worked with companies to understand how to reconsider their approach to using plastic packaging. We’re now looking at alternative packaging choices and what the relative impact might be on carbon emissions, and water and land use.”

Plastic rematerialised

It seems that our need for plastic is here to stay, and so Cambridge researchers are exploring how we re-use it – as well as developing alternatives to take its place.

Taylor Uekert, working with Dr Erwin Reisner in the Department of Chemistry, has developed a technology called photoreforming that turns plastic waste into hydrogen fuel, using only water, a photocatalyst and sunlight. The technology is still very new but already the researchers have produced enough hydrogen from polyester fibres to power a phone for 40 seconds.

Dr Aazara Oumayyah Pankan is also exploring electricity generation from waste plastic – this time using biology. She’s testing microorganisms from environments like toxic waste dumps for their ability to decompose plastic. Working with Dr Adrian Fisher in the Department of Chemical Engineering and Biotechnology, she aims for these ‘plastic composters’ to provide off-grid power for rural communities.

In Kenya, a coastal community has started converting waste plastic into bricks, using a method developed by a student-led team from Cambridge’s Department of Engineering and prototyped by the Kenyan community. They have just received an order for 2,000 bricks for a local school.

Physicist Professor Jeremy Baumberg is using plastic waste as the raw materials for low-cost 3D printers. His team’s approach is to design printable scientific instruments like microscopes for resource-poor countries to turn low-value waste into high-value locally manufactured components.

Meanwhile, biochemist Professor Paul Dupree and materials scientist Professor James Elliott have set out to design a completely new class of materials based on modified plant fibres that have some of the good properties of plastic and yet are easy to recycle or decompose naturally.

Case study: The solution catalyser

Bringing the right people together to solve a major global environmental problem like waste is essential.

With this in mind, Dr Curie Park from the Institute for Manufacturing took her emergent circular economy process for creating the right mix of people to Thailand, funded by a Global Challenges Research Fund Impact Acceleration Award.

“Thailand uses a staggering amount of single-use plastics every day, but its waste management system lags far behind its economic advances,” she explains. “We saw first-hand the marine waste at a coastal village, where plastic debris floats from the rivers and is washed up as current changes seasonally.

“Everyone recognised the problem, which seemed too big for any one individual to tackle. But there had been regular beach cleaning activities and some of this collected plastic could be turned into viable products locally.

“We brought together a construction company, an environmental NGO, university students, a local windsurfing world champion turned beach cleaning heroine, municipal officers, local primary schools and start-ups, and applied our innovation process.

“Giving everyone a chance to share their views, providing stimuli and sharing what’s happening in other communities ignited a creative momentum to come up with novel solutions. We ended up with 56 ideas for using the waste as a raw material – paddleboards, compost bins, roof tiles – seven of which are in the commercialisation pipeline by the construction company and the local start-ups.”

Curie Park and the local beach cleaning group in Thailand

Curie Park and the local beach cleaning group in Thailand

Words to live by

Put simply, plastic is incredibly useful – and it's being wasted.

“There’s a word in Japanese that conveys a feeling of regret when something useful is wasted. It’s mottainai,” says anthropologist Dr Brigitte Steger, from the Faculty of Asian and Middle Eastern Studies. As part of CirPlas, Steger and her team look at cultural attitudes to plastic and waste globally. Her own research focuses on Japan.

“The Japanese are very good citizens in terms of sorting and recycling but they also use a huge amount of plastic – and they don’t regard single-use plastic with mottainai,” she says.

In Tokyo, the 'Garbage Separation and Disposal' advice extends to 60 pages. “One woman being rehoused after the Fukushima Daiichi nuclear disaster told me she would only move to an area where she was familiar with the complexities of the recycling system,” says Steger.

Advice to householders in Tokyo on waste separation for recycling

Advice to householders in Tokyo on waste separation for recycling

“We need to understand what practical and moral needs plastic fulfils to know what can be done to shift behaviour towards living more sustainably. Moreover, policymakers define solutions in response to how problems are defined. We need to clarify these.”

What if we could shift our 'take, make, throw-away' plastic world towards 'recycle, recover, re-use'?

“Today’s cradle-to- grave economy sees around 80% of plastic landfilled, incinerated or lost into the natural environment,” says economist Dr Khaled Soufani. “It is argued by some that we are using resources 50% faster than can be replenished. It has also been said that by 2030 we will require the natural resources sources of two Earths, and by 2050, three.”

Soufani leads the Circular Economy Centre in Cambridge Judge Business School. He and Steger are contributing to CirPlas by asking how individuals, communities, companies and public bodies approach their use and recycling of plastic.

“What we need,” says Soufani, “is a circular economy with re-use of products and recycling of embedded materials into new products for as long as possible.”

Film: Khaled Soufani talks about moving towards a more sustainable future via the circular economy

Circularity by design

Cambridgeshire-based packaging company Charpak believes it is the first in the UK to adopt a ‘localised circular economy’ in which local plastic waste is collected, re-processed and re-manufactured into new packaging.

The company has been chosen by Soufani’s team as a case study to look at the viability of a circular business model. The translation of the circular economy in business models that eliminate plastic is relatively unexplored and so there's little guidance for practitioners who would like to adopt such a model.  The researchers are addressing this gap by mapping how Charpak has approached the circular economy and by estimating the impact of their efforts.

Worker at Charpak

Worker at Charpak

“Before any company will look at embedding circularity, they are going to ask a very simple question: how will it impact on me financially? Communities, companies and governing bodies need to see practical business cases and models in action,” adds Soufani.

“Minimising plastic leaking into our environment is a responsibility we take very seriously, so we must ensure plastic becomes a resource and not waste,” says Charpak Managing Director Paul Smith. “Why transport essential plastics resources nationwide, or overseas, and risk ocean plastics when the plastic resource is required for manufacture and re-manufacture within the UK? We want to be part of the solution.”

Soufani agrees, adding: “We need to shift from a culture of mass consumption and waste towards renewability, dematerialisation and reduced resource loss.

Our need to reduce, remake and recycle is a continuous journey towards circularity that will define our relationship with the planet forever. Khaled Soufani

Image credits:
Sky girl: Karina Tess
Water bottle in the ocean, Indonesia: Brian Yurasits
Plastic in a field: Masha Kotliarenko
Manufacture of plastic drinking bottles: Jonathan Chng

Top Summary: 

How do we shift our 'take, make, throw-away' plastic world towards 'recycle, recover, re-use'? It's time for blue-sky thinking plus practical measures in the battle to reduce plastic waste. 

Image: Affiliation (schools and institutions): Department of ChemistryDepartment of EngineeringCambridge Institute for Sustainability LeadershipDepartment of Chemical Engineering and BiotechnologyDepartment of PhysicsDepartment of BiochemistryDepartment of ZoologyDepartment of Materials Science and MetallurgyCambridge Judge Business SchoolInstitute for Manufacturing (IfM)Faculty of Asian and Middle Eastern StudiesSchool of the Physical SciencesSchool of TechnologySchool of the Biological SciencesSchool of Arts and HumanitiesExternal Affiliations: UK Research and Innovation (UKRI)CharpakPeople (our academics and staff): Erwin ReisnerAndre SerrenhoJonathan CullenRonan DalyDavid AldridgeTaylor UekertAazara Oumayyah PankanAdrian FisherJeremy BaumbergPaul DupreeJames ElliottBeverley CornabyKhaled SoufaniBrigitte StegerSubject (including Spotlight on ... where applicable): plasticSustainable EarthWasterecyclingcircular economymaterialsInnovationconservationEnvironmentStoriesSection: ResearchNews type: Features
Categories: Latest News (<front>)

Suction cups that don't fall off

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that don't fall off

Insects in torrential rivers
may inspire engineering solutions

The aquatic larvae of the net-winged midge have the unique ability to move around at ease on rocks in torrential rivers using super-strong suction organs. Powerful modern imaging techniques have now revealed the structure of these organs in intricate detail, providing an insight into how they work so reliably. The findings, reported in the journal BMC Zoology, may inform the development of better man-made suction cups that perform well on a variety of surfaces.

The larvae have the ability to quickly detach and reattach to underwater rocks in torrential alpine rivers that can flow as fast as three metres per second. Their highly specialised suction organs are so strong that only forces over 600 times their body weight can detach them. Being in such fast flowing water puts them out of harm’s way, since competitors or predators are unlikely to survive in this challenging environment.

“The force of the river water where the larvae live is absolutely enormous, and they use their suction organs to attach themselves with incredible strength. If they let go they’re instantly swept away,” said Victor Kang, a PhD student in the University of Cambridge’s Department of Zoology and first author of the paper. “They aren’t bothered at all by the extreme water speeds – we see them feeding and moving around in all directions.”

Net-winged midge larva uses its powerful suction organs to crawl on a rock surface beneath a fast-flowing alpine stream.

Net-winged midge larva uses its powerful suction organs to crawl on a rock surface beneath a fast-flowing alpine stream.

The researchers found that a central piston, controlled by specific muscles, is used to create the suction and enable each larva to form a very tight seal with the surface of the rock. A dense array of tiny hairs come into contact with the rock surface, helping to keep the larva in place. When it needs to move, other muscles control a tiny slit on the suction disc, pulling the disc open to allow the suction organ to detach. This is the first time such an active detachment mechanism has been seen in any biological system.

Slit on the suction disc - a unique feature that allows the net-winged midge larvae to rapidly detach and move around.

Slit on the suction disc - a unique feature that allows the net-winged midge larvae to rapidly detach and move around.

The work focused on two species of the larvae – Liponeura cinerascens and Liponeura cordata – found in the fastest flowing parts of alpine rivers near Innsbruck, Austria. Despite only wading into the river up to their knees, the researchers found it difficult to stay upright. The larvae they found there were grazing on the underwater rocks, apparently oblivious to the torrents bearing down on them.

“These natural structures have been optimised through millions of years of evolution. We want to learn from them to create better engineered products,” said Dr Walter Federle, an expert in Comparative Biomechanics at the University of Cambridge who led the study.

L. cinerascens larva

L. cinerascens larva

By collaborating with colleagues at the Institute of New Materials, Saarbrücken, Germany, the researchers are using their findings to develop ‘bio-inspired’ suction cups. Current artificial suction cups only work well on smooth, clean surfaces, like a car windscreen or inside a clean-room facility. The aquatic net-winged midge larvae live on rough, dirty surfaces yet can walk around with ease. Such highly reliable controlled attachment and detachment has many potential industrial applications.

“By understanding how the larvae’s suction organs work, we now envisage a whole host of exciting uses for engineered suction cups,” said Federle. “There could be medical applications, for example allowing surgeons to move around delicate tissues, or industrial applications like berry picking machines, where suction cups could pick the fruit without crushing them.”

The aquatic larvae of net-winged midges have fascinated insect specialists for over a century. Their suction organs have the highest attachment strength ever recorded in insects. Using scanning electron microscopy, confocal laser scanning microscopy, and X-ray computed micro-tomography (micro-CT), this study has revealed the internal structure of the suction organs in three dimensions and provided new insights into their function.

Reference: Kang, V. et al, 'Morphology of powerful suction organs from blepharicerid larvae living in raging torrents.' BMC Zoology (2019). DOI:10.1101/666537

Additional photo captions: Second image - suction organ imaged using laser scanning confocal microscopy; below - fast flowing alpine stream, a typical habitat for the net-winged midge larvae. All images by Victor Kang.

Top Summary: 

The aquatic larvae of the net-winged midge have the unique ability to move around at ease on rocks in torrential rivers using super-strong suction organs. Powerful modern imaging techniques have now revealed the structure of these organs in intricate detail, providing an insight into how they work so reliably. 

Image: Affiliation (schools and institutions): School of the Biological SciencesDepartment of ZoologyPeople (our academics and staff): Walter FederleVictor KangSection: ResearchNews type: News
Categories: Latest News (<front>)