The future of plastics: reusing the bad and encouraging the good


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Plastic pollution: discarded plastic bags are a hazard to marine life.
Richard Whitcombe/Shutterstock, CC BY-ND

Kim Pickering, University of Waikato

Plastics have got themselves a bad name, mainly for two reasons: most are made from petroleum and they end up as litter in the environment.

However, both of these are quite avoidable. An increased focus on bio-derived and degradable composites as well as recycling could lessen pollution and, in fact, plastics could make a positive contribution to the environment.

Plastics for bad

The durability of plastics makes them so useful, but at the same time, it turns them into a persistent (and increasingly big) blot on the landscape, or more importantly the seascape, once discarded.


Read more: This South Pacific island of rubbish shows why we need to quit our plastic habit


We’ve known for a while that bulk plastics are polluting the oceans. Converging sea currents are accumulating plastic waste in a floating island known as the Great Pacific Garbage Patch, which now covers an area larger than Greenland. The bigger bits of plastic are life-threatening to marine life and sea birds. They can strangle marine mammals or birds and build up in their stomachs and guts.

A dolphin entangled in fishing line and plastic bags (Indian Ocean).
from Shutterstock, CC BY-ND

More recently, awareness of microplastics has raised concern about their ubiquitous presence in the food chain. Commentators suggest that by 2050 there will be as much plastic in the sea as there is fish. Who wants to go catch some plastic then?


Read more: How microplastics make their way up the ocean food chain into fish


Beyond that, plastic production currently relies on petroleum and that has raised issues about health hazards, generally associated with petroleum-based products during production, use and disposal.

Plastics for good

Plastics can contribute positively to the environment in the following ways:

  • Reduced food wastage

Between one-quarter and one-third of all food produced is wasted through spoilage. But without plastic packaging, it would be considerably worse and have a larger carbon footprint.

Many of the recycling enthusiasts I know do not think about throwing out spoiled food that required energy in terms of planting, cultivating, harvesting and transporting and therefore will have added to greenhouse gas emissions.

  • Lightweight transport

The use of plastics in transportation (cars, trains and planes) will reduce fuel consumption. Their application (along with reinforcing fibres) in aerospace as alternatives to traditional metallic alloys has brought huge gains of fuel efficiency over the last few decades.

Incorporation of fibre-reinforced plastics in the Boeing 787 Dreamliner, for example, has resulted in fuel efficiencies that are similar to a family car (when measured by kilometres travelled per person). By the way, carbon fibre, the aerospace fibre of choice, is produced from plastic.

There are good things about plastics including benefits for the environment, but is it possible to make use of the good aspects and avoid the bad?

Future proofing plastics

Plastics are, chemically speaking, long chains or large cross-linked structures most commonly made up of a framework of carbon atoms.

For a long time, we have been using bio-derived plastics – naturally occurring materials such as animal skins including leather, gut and wood. These forms of plastic are complicated chemical structures that can only be made in nature at this stage.

Some of the early synthesised plastics were made from naturally occurring materials such as casein (from dairy) that was used for simple items such as buttons. The development of petroleum-based plastics has been a major distraction from such materials.

However, in the last couple of decades, bio-derived plastics have become available that provide good replacements. These include starch-based plastics such as polylactide (PLA), which is produced from corn starch, cassava roots or sugarcane and processed in the same way as petroleum-based plastics. Such plastics can be foamed or used to make drink bottles.

Plastic bottles ready to be recycled.
From Shutterstock, CC BY-ND

Recycling plastics is another essential step towards reducing the environmental load. Let’s face it: it is people who are doing the littering, not the plastics themselves. More effort could go into waste collection and a carrot/stick approach should include disincentives for littering and a plastic tax which would exclude recycled plastics.

Incentives are also needed to encourage product development that takes account of the full life cycle. In Europe, for instance, legislation has made it compulsory in the automotive industry for at least 85% of a car to be recycled. This has had a dramatic influence on the materials and design used in the industry.

Even with best efforts, it is unrealistic that we would capture all plastics for recycling. Biodegradable plastics could be a useful tool for preventing environmental damage. PLA (polylactide) is biodegradable, though slow to break down, and there are other forms available.

This highlights the need for more research into controlling biodegradability, taking into account different applications and the need for infrastructure to deal with biodegradable plastics at the end of their life. Obviously, we don’t want our planes biodegrading during their 20 years of service, but one-use water bottles should break down within a short time after use.

The planet doesn’t have to become a toxic rubbish dump. In the short term, this will need some government action to encourage bio-derived, recyclable and biodegradable plastics to allow them to compete with petroleum-based products.

The ConversationThere are signs of improvement: increasing awareness of the harm plastics cause and a willingness of consumers to pay for plastic bags or to ban them. We need to stop dumping in our own backyard and remember that the environment is where we live. We ignore it at our peril.

Kim Pickering, Professor of materials science and engineering, University of Waikato

This article was originally published on The Conversation. Read the original article.

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Pristine paradise to rubbish dump: the same Pacific island, 23 years apart



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The same beach on Henderson Island, in 1992 and 2015.

Jennifer Lavers, University of Tasmania and Alexander Bond, Royal Society for the Protection of Birds

A few weeks ago, the world woke to the story of Henderson Island, the “South Pacific island of rubbish”. Our research revealed it as a place littered with plastic garbage, washed there by ocean currents.

This was a story we had been waiting to tell for more than a year, keeping our discoveries under wraps while we worked our way through mountains of data and photographs.

Our May 2017 video story detailing the rubbish on Henderson Island.

Everyone wanted to know how the plastic got there, and fortunately that is a question that our understanding of ocean currents can help us answer. But the question we couldn’t answer was: when did it all start to go so wrong?

This is the million-dollar question for so many wild species and spaces – all too often we only notice a problem once it’s too big to deny, or perhaps even solve. So when did Henderson’s sad story start? The answer is: surprisingly recently.

An eloquent photo

During our research we had reached out to those who had previously worked on Henderson Island or in nearby areas, to gain a better understanding of what forces contributed to the enormous piles of rubbish that have floated to Henderson’s sandy beaches.

Then, after our research was published and the world was busy reading about 37 million plastic items washed up on a remote south Pacific island, we received an email from Professor Marshall Weisler from the University of Queensland, who had seen the news and got in touch.

In 1992, he had done archaeological surveys on Henderson Island. The photos he shared from that expedition provided a rare glimpse into the beginning of this chapter of Henderson Island’s story, before it became known as “garbage island”.

Henderson Island in happier times.
Marshall Weisler, Author provided
The same stretch of beach in 2015.
Jennifer Lavers, Author provided

There are only 23 years between these two photos, and the transformation is terrifying – from pristine South Pacific gem to the final resting place for enormous quantities of the world’s waste.

Remember, this is not waste that was dumped directly by human hands. It was washed here on ocean currents, meaning that this is not just about one beach – it shows how much the pollution problem has grown in the entire ocean system in little more than two decades.

To us, Henderson Island was a brutal wake-up call, and there are undoubtedly other garbage islands out there, inundated and overwhelmed by the waste generated in the name of progress. Although the amount of trash on Henderson is staggering – an average of 3,570 new pieces arrive each day on one beach alone – it represents a minute fraction of the rubbish produced around the globe.

Cleanup confounded

In the wake of the story, the other big question we received (and one we should have seen coming) was: can I help you clean up Henderson Island? The answer is no, for a very long list of reasons – some obvious, some not.

To quote a brilliant colleague, what matters is this: if all we ever do is clean up, that is all we will ever do. With thousands of new plastic items washing up on Henderson Island every day, the answer is clear.

The solution doesn’t require travel to a remote island, only the courage to look within. We need to change our behaviour, to turn off the tap and stem the tide of trash in the ocean. Our oceans, our islands, and our planet demand, and deserve it.

However difficult those changes may be, what choice do we have?

Prevention, not cure

While grappling with the scale of the plastics issue can at times be overwhelming, there are simple things you can do to make a difference. The solutions aren’t always perfect, but each success will keep you, your family, and your community motivated to reduce plastic use.

First, ask yourself this: when did it become acceptable for something created from non-renewable petrochemicals, extracted from the depths of the Earth and shipped around the globe, to be referred to as “single use” or “disposable”? Your relationship with plastic begins with the language you use.

But don’t stop there: here are a couple of facts illustrating how you can challenge yourself and make a difference.

Challenge: switch to bamboo toothbrushes, which cost just a few dollars each and are available from a range of online retailers or wholefood shops.

Challenge: switch to products that use crushed apricot kernels, coconut shell, coffee grounds, or sea salts as natural exfoliants.

The ConversationThese are only small changes, and you can undoubtedly think of many more. But we need to start turning the tide if we are to stop more pristine places being deluged with our garbage.

Jennifer Lavers, Research Scientist, Institute for Marine and Antarctic Studies, University of Tasmania and Alexander Bond, Senior Conservation Scientist, Royal Society for the Protection of Birds

This article was originally published on The Conversation. Read the original article.

This South Pacific island of rubbish shows why we need to quit our plastic habit


Jennifer Lavers, University of Tasmania

A remote South Pacific island has the highest density of plastic debris reported anywhere on the planet, our new study has found. The Conversation

Our study, published in the journal Proceedings of the National Academy of Sciences, estimated that more than 17 tonnes of plastic debris has washed up on Henderson Island, with more than 3,570 new pieces of litter arriving every day on one beach alone.

Our study probably actually underestimates the extent of plastic pollution on Henderson Island, as we were only able to sample pieces bigger than two millimetres down to a depth of 10 centimetres. We also could not sample along cliffs.
Jennifer Lavers, Author provided

It is estimated that there are nearly 38 million pieces of plastic on the island, which is near the centre of the South Pacific Gyre ocean current.

Henderson Island, marked here by the red pin, is in the UK’s Pitcairn Islands territory and is more than 5,000 kilometres from the nearest major population centre. That shows plastic pollution ends up everywhere, even in the most remote parts of the world.
Google Maps

A 2014 paper published in the journal PLOS One used data from surface water all over the world. The researchers estimated that there are 5.25 trillion pieces of plastic in the top 10 centimetres of the world’s oceans.

Plastics pose a major threat to seabirds and other animals, and most don’t ever break down – they just break up. Every piece of petrochemical-derived plastic ever made still exists on the planet.

Jennifer Lavers, Research Scientist, Institute for Marine and Antarctic Studies, University of Tasmania

This article was originally published on The Conversation. Read the original article.

Indonesia vows to tackle marine pollution


Thomas Wright, The University of Queensland

It is wet season in Bali, Indonesia, a popular tourist destination for Australian, Russian, German, Chinese and Japanese visitors. The Conversation

As the rain pounds down on banana leaves and rice fields, the rivers fill up and irrigation systems overflow. With it, the water masses bring trash in bulk: anything from food wrappers and plastic bags to bottles and other domestic waste.

To tackle the issue of marine pollution, several organisations got together in Nusa Dua – a popular tourist destination – and other locations across Bali to stage the largest beach clean-up the island has seen.

Around 12,000 volunteers collected 40 tons of garbage at 55 locations, according to the One Island, One Voice campaign page.

While the beach clean-up was a hugely successful awareness campaign and a great promotion which highlights the efforts done around the island, it is only a drop in the ocean of global marine pollution.

Plastic pollution in Indonesia

In recent years, Bali has seen growing environmental problems such as pollution and freshwater scarcity. Popular tourist destination Kuta beach is regularly covered in waste. Most of this is plastic that washes ashore during the rainy season.

The island’s garbage dumps are reportedly overflowing,. This makes solid waste management a pressing issue. Substantial groundwater resources are predicted to run dry by 2020, threatening freshwater resources.

On top of that, Indonesia is the world’s second-biggest marine polluter after China, discarding 3.22 million metric tons of waste annually. This accounts for 10% of the world’s marine pollution.

The effects marine pollution has on ecosystems and humans are beginning to be well documented. Marine scientists have found harmful consequences of marine pollution to sea life, ecosystems and humans.

Plastic can kill ocean mammals, turtles and other species that consume it. It can also poison food and water resources, as harmful chemicals leach out of the plastic.

It poses threats to human health as well. Plastics leach cancerous toxins. After being consumed by marine species, they enter the food chain, eventually ending up in fish we eat.

Marine plastic pollution is a global problem and Indonesia’s beaches present pressing examples to study the socio-economic effects this has on coastal communities.

Most vulnerable to marine pollution left out of global discussions

Last month, The Economist held the fourth Oceans Summit in Bali.

The summit was attended by state leaders such as Indonesian Vice President Jusuf Kalla, representatives of major global economic organisations such as Citigroup managing director Michael Eckhart, and celebrity and entrepreneur Adrian Grenier.

Speakers and panels discussed a number of topics, including the “blue economy” and how companies and governments can participate in this marine-based sustainable industry.

During the summit, the Indonesian government announced it will pledge US$1 billion to curb ocean waste by 70% by 2025. It’s an ambitious objective, which shows dedication and commitment to a plastic-free future.

But not all voices are heard in this global debate. Many Bali-based environmental organisations engaged in education programs were not represented at the summit. Those economically most vulnerable to pollution – such as beach vendors, fishermen and others employed in the marine tourism trade – appear to be left out of the conversation.

Marine pollution and tourism

The Indonesian government plans to boost tourism and increase national visitors from 9.7 million in 2015 to 20 million by 2020. Such increases in visitor numbers and population will raise consumption and waste production, further pressuring the island’s infrastructure and ecosystems.

With tourism as the island’s largest economic sector, many Balinese people depend on foreign visitors to earn an income. Some tourism operators are concerned that if the plastic problem increases it will damage this industry. They fear tourists will stop coming to Bali if it is too polluted.

Marine communities may also suffer negative socio-economic consequences, as fishermen can lose their livelihood and tourism operators lose their customers.

While some tourism operators understand that clean beaches are key in attracting international tourists, the expected growth is likely to further stress Bali’s environment.

What is being done?

Efforts by activists, community groups and NGOs to clean beaches play a key role in protecting Bali’s environment. But they are only a temporary fix and don’t tackle the causes of this global problem.

Such groups are leading the fight against over-development and pollution through protests, clean-up events and educational programs.

Campaigners from Bali-based environmental youth group “Bye Bye Plastic Bags” advocate for an island-wide ban on plastic bags. They also spoke at the Ocean Summit.

And while they convinced Bali’s governor to commit to make the island plastic-bag-free by 2018, continued development of legislation, regulation and industry guidelines is needed to save Indonesia’s waterways from drowning in waste.

Thomas Wright, PhD Candidate in Anthropology, The University of Queensland

This article was originally published on The Conversation. Read the original article.

Microbes: the tiny sentinels that can help us diagnose sick oceans


Katherine Dafforn, UNSW Australia; Emma Johnston, UNSW Australia; Inke Falkner, and Melanie Sun, UNSW Australia

Microbes – bacteria and other single-celled organisms – may be tiny, but they come in huge numbers and we rely on them for clean water, the air we breathe and the food we eat.

They are nature’s powerhouses but they have often been ignored. We previously lacked the capacity to appreciate truly their diversity, from micro-scales right up to entire oceans.

Recent advancements in genetic sequencing have revealed this diversity, and our research, published in Frontiers in Aquatic Microbiology this week, shows how we can use this information to understand human impacts on an unseen world – making microbes the new sentinels of the sea.

A sea of microbes

The great majority of bacteria and other microbes are extremely beneficial, performing vital roles such as recycling nutrients.

The number of bacteria on Earth is estimated at 5×10³⁰ (or 5 nonillion, if you prefer), and many of them live in the ocean. There are 5 million bacteria in every teaspoon of seawater, and more bacteria in the ocean than stars in the known universe.

Guess how many microbes?
Victor Morozov/Wikimedia Commons, FAL

There are yet more bacteria in the world’s soils and sediments, with estimates of between 100 million and 1 billion bacteria per teaspoon. These sediments are vital for recycling nitrogen, particularly in coastal sediments closest to human populations. Without bacteria and other microbes, sediments would turn into unsightly, pungent piles of waste.

Microbial services are not limited to recycling. Many microbes, including cyanobacteria, function like tiny plants by using sunlight to produce oxygen and sugars. Due to their extraordinary number in the world’s oceans, the amount of oxygen these organisms produce is equal to that of all plants on land.

Marine sentinels

Until recently, finding out just how many different types of microbes there are was relatively difficult. How do you identify and study millions of different organisms that are not visible to the naked eye?

Bacteria, for example, had to be grown in the laboratory in large colonies to be seen. But only 1-3% of bacteria can be cultured successfully.

Advances in genetics together with the development of molecular tools have allowed researchers to investigate marine bacteria in their natural environment. Microbial communities can now be grouped by the role they play in ecosystems and how these groups respond to environmental gradients.

We can use these new tools to measure ecosystem health, which is crucial to managing human impacts on our coastlines, particularly in estuaries. Early studies have found shifts in bacterial community composition to be good indicators of contaminants

Different areas of harbours, such as Sydney Harbour, have distinct bacterial communities. These patterns may be driven by circulation. The outer harbour, which is flushed with seawater on every tidal cycle, is dominated by photosynthetic cyanobacteria. The upper harbour, with less flushing and more runoff, is dominated by soil-related bacteria and those adapted to nutrient-rich environments.

In our waterways, pollutants such as metals bind to fine particles and settle as sediment. This exposes sediment-dwelling organisms to a multitude of toxic products. What effect do these toxic substances have on sediment microbes?

Recent evidence from a large survey of eight estuaries suggests that microbes are far more sensitive to contaminants than larger animals and plants. This survey also revealed that toxic substances were linked to changes in community structure and a reduction in community diversity. This is especially alarming given that a diversity of microbes is essential to nutrient recycling.

Diagnosing wounded seas

It would be great if we could use particular microbes to diagnose human impacts. For instance, certain microbes can indicate water quality.

A technique called metagenomics is revealing the true depth of microbial diversity by pooling DNA sequences from all the species in a sample. It then works backwards to construct a genetic overview of the entire community.

However, while metagenomics can give us important information about the identity of microbes in a community, it can’t tell us what they are doing or how their functions change in response to environmental stressors and human activities.

Metatranscriptomics takes the sequencing approach one step further and characterises gene expression in a microbial community, which can be linked to crucial ecosystem services such as nutrient cycling.

Similar to their use for diagnosis of ailments in humans, molecular tools are being used to diagnose human impacts on earth by observing changes in microbes across polluted and unpolluted environments. They can even detect very small amounts of toxic substances. Because of their diversity, they can potentially be used to detect a wide range of human impacts.

This allows us to identify environmental impacts early, potentially limiting greater loss in larger organisms.

With the new tools to “see” microbes and their importance, we are now perfectly poised to advance our understanding of how microbes are responding to environmental change. They are sentinels of our increasingly human-affected waterways.

The Conversation

Katherine Dafforn, Senior Research Associate in Marine Ecology, UNSW Australia; Emma Johnston, Professor of Marine Ecology and Ecotoxicology, Director Sydney Harbour Research Program, UNSW Australia; Inke Falkner, Community Outreach Coordinator for Sydney Harbour Research Program, Sydney Institute of Marine Science, and Melanie Sun, PhD Candidate – Environmental Research, UNSW Australia

This article was originally published on The Conversation. Read the original article.