Scientists predict the size of plastics animals can eat

New equation could help determine risk of plastics to any species -- and amount of plastic entering food chains

Date: March 27, 2020

Source: Cardiff University

A team of scientists at Cardiff University has, for the first time, developed a way of predicting the size of plastics different animals are likely to ingest.

The researchers, from the University's Water Research Institute, looked at the gut contents of more than 2,000 animals to create a simple equation to predict the size of a plastic item an animal can eat, based on the length of its body.

In the study, published today in Nature Communications, they report that the length of an animal can be used to estimate the biggest piece of plastic it can eat -- and this was about 5% (a twentieth) of the size of the animal.

The researchers say that as the plastic pollution problem escalates, it is vital to be able to quickly assess the risk of plastics to different species around the world.

This work could also help scientists measure the risk of plastic pollution to ecosystems and food supplies -- and ultimately the risk to human health.

By trawling through published data, the team found plastics ingested by marine and freshwater mammals, reptiles, fishes and invertebrates, from 9mm-long fish larvae to a 10m-long humpback whale.

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What I learned by pulling a straw out of a sea turtle and video tapped it - via Herp Digest

Then when my video went viral, I found that communicating to non-scientists is uncomfortable — and effective 

by Christine Figgener, Nature 563, 157 (2018)

Three years ago, I uploaded a video of a sea turtle in distress. While collecting data for my PhD off the coast of Costa Rica, my team decided to remove what looked to be a barnacle encrusted in the nostril of the turtle, which we had captured for a research study. The object turned out to be a 10-centimetre section of a disposable plastic drinking straw. We filmed the process. That upsetting video (see go.nature.com/2qfci6f) has now had more than 33 million views, and became an emblem of the anti-straw movement.

It also thrust me into a world of high-profile advocacy I never expected to enter. I became involved in a documentary project, and community activists who were launching plastic-free campaigns asked for my support; I’ve gone to schools, conferences and screenings to talk about a subject that is not my main research focus. Last month, to my surprise, Time named me a 2018 Next Generation Leader, alongside celebrities such as Ariana Grande and Hasan Minhaj. All this has taught me that communicating beyond academia is worth trying, but it demands constant vigilance and caution.

I always have to remind non-scientists that my video is, of course, not the first documentation of how plastic harms marine wildlife. A legion of scientific articles does exactly that. But, for many, it takes videos such as mine to make these articles less abstract. I’d spent years making videos that I hoped would encourage conservation by showing the beauty of nature. They had little effect compared with my video of a bleeding turtle and a spontaneous anti-straw tirade.

Many scientists shy away from the press — or from uploading videos that show emotion, especially anger and frustration. We fear the simplification and inaccuracies likely to be introduced into accounts of our research, which could cause us to lose credibility with peers and funders. Yet, these routes might be the most effective way of getting information to policymakers and citizens, and so promoting conservation.

This year, companies including Alaska Airlines, Disney and Starbucks announced programmes to phase out plastic straws. Seattle, Washington, and San Francisco, California, among other cities, have moved to ban or limit them. Of course, straws are just a tiny fraction of the plastics in the ocean. (Roughly, they make up less than 0.03% of the more than 8 million tonnes of plastic waste, largely consumer trash and fishing nets, that makes its way to the ocean every year, mainly from middle-income countries.)

I take care to explain that the straw is emblematic of unnecessary plastic items and how human activity harms oceans. The message is getting through. Last week, the European Union moved to prohibit several single-use plastics, including plates and cutlery.

Activists need scientists’ input. When you’re trying to preserve species effectively and have limited funds, you need to know which life stages have the highest chance of survival and whether there is enough suitable habitat left for a species to even sustain larger numbers. Sometimes people are eager to undertake intense hands-on work (such as rescuing turtle eggs by digging them up and reburying them) even when less-dramatic efforts (such as establishing protected beach areas) would be sufficient and longer lasting.

Delivering compelling messages is difficult. I am used to obsessing over my data, not over how I look on camera. My research is dirty and smelly, full of long hours and unkempt hair. Conservation campaigns focus more on appearances, marketing and selling.

Thanks to my video, I have acquired a thicker skin and an eclectic set of skills ranging from copyright law, social-media marketing and unconventional ways of fundraising (I started a GoFundMe page for research). I learnt to ignore most rude and ignorant remarks: for instance, claims that I shoved the straw into the turtle’s nose for self-promotion. If I respond, I draft an unemotional e-mail debunking accusations point by point with established facts.

What rankles more is when people try to take advantage of me. As in academia, philanthropy and advocacy are full of big egos that sometimes care more about advancing themselves than a cause. They are also less likely to buy into an ideal of citing and crediting others. I have learnt to be careful about how others use my work.

It might seem to other early-career scientists that I won the lottery by publishing a gruesome video rather than hundreds of scientific articles, but I am not even sure whether my modicum of celebrity makes me more or less employable. My advocacy has taken time away from my research. I still need to finish my dissertation on the migration patterns of olive ridley sea turtles (Lepidochelys olivacea). Yet I am scared that if I turn down speaking engagements or other chances to spread the message about plastics pollution, I’m letting down the creatures I’d hoped to help by studying them.

Although it might never feel entirely comfortable, I intend to keep straddling both academia and advocacy. After the straw-extraction video went viral, my colleague and I decided that we needed a conventionally citable publication, and so we wrote a piece that appeared in Marine Turtle Newsletter (N. J. Robinson and C. Figgener Mar. Turtle Newsl. 147, 5–6; 2015). That article exemplifies why doing outreach beyond academia is so important. Maybe a few hundred scientists read the peer-reviewed article, whereas millions of people saw the video. Which had the bigger impact?

Plastic and other waste found in British mussels

8 June 2018

Researchers have found tiny pieces of plastic in all the samples of mussels they tested in British seawaters and bought from local supermarkets.

The scientists, from the University of Hull and Brunel University, said the contamination from microplastics and other human debris, such as cotton and rayon, was significant and widespread.

Mussels feed by filtering seawater.

They team says more work is needed to understand the health implications of consuming the seafood.

The group's study is published in the journal Environmental Pollution.

It sampled wild mussels from eight coastal locations and mussels purchased from eight unnamed supermarkets. Some of the shop-bought mussels were imported from abroad.

The investigation found that for every 100g of mussels being eaten, an estimated 70 pieces of tiny debris were also being taken in.

The analysis determined that more debris was present in wild mussels than farmed ones. And in the mussels bought in supermarkets, cooked or frozen varieties contained more particles than those that had been freshly caught.

This is just one more study that confirms the ubiquity of microplastics in the environment. These particles are in many food products, in bottled drinking water; they are even in the air.

"It is becoming increasingly evident that global contamination of the marine environment by microplastic is impacting wildlife and its entry into the food chain is providing a pathway for the waste that we dispose of to be returned to us through our diet," said Prof Jeanette Rotchell from Hull University.

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Fish prefer to eat plastic over food – and it is killing them, study suggests

'The effects on aquatic ecosystems could be profound,' experts warn

Ian Johnston Science Correspondent 

1 hour  ago

Microplastic particles appear to be killing fish because their larvae prefer to eat them rather than their actual food, researchers have warned.

With fears that the amount of plastic in the oceans could soon equal the weight of fish in the sea, scientists have become increasingly concerned about the effects on the marine environment.

Now a study published in the journal Science has found that baby perch will actively choose to eat plastic over the plankton they would normally feed on.

The researchers said this greatly increased mortality rates of the perch, stunting their growth and appearing to change usually innate behaviour.

For example, they seemed to lose the ability to smell a predator that made them much more vulnerable.

Professor Peter Eklov, a co-author of the Science paper, said: “This is the first time an animal has been found to preferentially feed on plastic particles and is cause for concern.

“Increases in microplastic pollution in the Baltic Sea and marked recruitment declines of the coastal keystone species, like perch and pike, have recently been observed. 

“Our study suggests a potential driver for the observed … increased mortality.”

When placed in a tank with a pike, perch exposed to microplastic were eaten four times more quickly than perch that had not been eating plastic. 

All the plastic-fed fish had been killed within 48 hours.

Fellow researcher Oona Lpnnstedt stressed the effects of prey fish eating large amounts of plastic was likely to be felt throughout the food chain.

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