Plastic debris is gradually broken down into smaller and smaller fragments in the ocean, until it forms particles smaller than 5mm, known as microplastics. Our new research shows that powerful currents sweep these microplastics along the seafloor into large “drifts”, which concentrate them in astounding quantities. We found up to 1.9 million pieces of microplastic in a 5cm-thick layer covering just one square metre – the highest levels of microplastics yet recorded on the ocean floor.
While microplastics have been found on the seafloor worldwide, scientists weren’t sure how they got there and how they spread. We thought that microplastics would separate out according to how big or dense they were, in a similar manner to natural sediment. But plastics are different – some float, but more than half of them sink.
We’ve now discovered how a global network of deep-sea currents transports microplastics, creating plastic hotspots within vast sediment drifts. By catching a ride on these currents, microplastics may be accumulating where deep-sea life is abundant.
From bedroom floors to the seafloor
We surveyed an area of the Mediterranean off the western coast of Italy, known as the Tyrrhenian Sea, and studied the bottom currents that flow near the seafloor. These currents are driven by differences in water salinity and temperature as part of a system of ocean circulation that spans the globe. Seafloor drifts of sediment can be many kilometres across and hundreds of metres high, forming where these currents lose their strength.
We analysed sediment samples from the seafloor taken at depths of several hundred metres. To avoid disturbing the surface layer of sediment, we used samples taken with box-cores, which are like big cookie cutters. In the laboratory, we separated microplastics from the sediment and counted them under microscopes, analysing them using infra-red spectroscopy to find out what kinds of plastic polymer types were there.
Most microplastics found on the seafloor are fibres from clothes and textiles. These are particularly insidious, as they can be eaten and absorbed by organisms. Although microplastics on their own are often non-toxic, studies show the build-up of toxins on their surfaces can harm organisms if ingested.
These deep ocean currents also carry oxygenated water and nutrients, meaning that the seafloor hotspots where microplastics accumulate may also be home to important ecosystems such as deep-sea coral reefs that have evolved to depend on these flows, but are now receiving huge quantities of microplastics instead.
What was once a hidden problem has now been uncovered – natural currents and the flow of plastic waste into the ocean are turning parts of the seafloor into repositories for microplastics. The cheap plastic goods we take for granted eventually end up somewhere. The clothes that may only last weeks in your wardrobe linger for decades to centuries on the seafloor, potentially harming the unique and poorly understood creatures that live there.
In eight years, US environmentalist and social media star Lauren Singer had never sent an item of rubbish to landfill. But last month, in an impassioned post to her 383,000 Instagram followers, she admitted the reality of COVID-19 has changed that.
I sacrificed my values and bought items in plastic. Lots of it, and plastic that I know isn’t recyclable in NYC (New York City) recycling or maybe even anywhere … why would I go against something that I have actively prioritised and promoted?
Singer wrote that as the seriousness of COVID-19 dawned, she stocked up on items she’d need if confined to her home for a long period – much of it packaged in plastic.
Her confession encapsulates how the pandemic has challenged those of us who are trying to reduce our waste. Many sustainability-conscious people may now find themselves with cupboards stocked with plastic bottles of hand sanitiser, disposable wipes and takeaway food containers.
So let’s look at why this is happening, and what to do about it.
Sustainability out the window
We research how consumers respond to change, such as why consumers largely resisted single-use plastic bag bans. Recently we’ve explored how the coronavirus has changed the use of plastic bags, containers and other disposable products.
Amid understandable concern over health and hygiene during the pandemic, the problem of disposable plastics has taken a back seat.
Restaurants and other food businesses can now only offer home delivery or takeaway options. Many won’t allow customers to bring their own containers, defaulting to disposables which generate plastic waste. This means many consumers can’t reduce their plastic waste, even if they wanted to.
Demand for products such as disposable wipes, cleaning agents, hand sanitiser, disposable gloves and masks is at a record high. Unfortunately, they’re also being thrown out in unprecedented volumes.
And the imperative to prevent the spread of coronavirus means tonnes of medical waste is being generated. For example, hospitals and aged care facilities have been advised to double-bag clinical waste from COVID-19 patients. While this is a necessary measure, it adds to the plastic waste problem.
Cause for hope
Sustainability and recycling efforts are continuing. Soft plastics recycler Red Cycle is still operating. However many dropoff points for soft plastics, such as schools and council buildings, are closed, and some supermarkets have removed their dropoff bins.
Boomerang Alliance’s Plastic Free Places program has launched a guide for cafes and restaurants during COVID-19. It shows how to avoid single-use plastics, and what compostable packaging alternatives are available.
As the guide notes, “next year the coronavirus will hopefully be a thing of the past but plastic pollution won’t be. It’s important that we don’t increase plastic waste and litter in the meantime.”
A relaxation on plastic bag bans – even if temporary – is likely to have long-term consequences for consumer behaviour. Research shows one of the biggest challenges in promoting sustainable behaviours is to break old habits and adopt new ones. Once people return to using plastic bags, the practice becomes normalised again.
In Europe, the plastic industry is using the threat of coronavirus contamination to push back against a ban on single-use plastics such as food containers and cutlery.
Such reframing of plastic as a “protective” health material can divert attention from its dangers to the environment. Prior research, as well as our preliminary findings, suggest these meanings matter when it comes to encouraging environmentally friendly behaviours.
Many people are using their time at home to clear out items they no longer need. However, most second-hand and charity shops are closed, so items that might have had a second life end up in landfill.
Similarly, many tool, book and toy libraries are closed, meaning some people will be buying items they might otherwise have borrowed.
What to do
We can expect the environmental cause will return to the foreground when the COVID-19 crisis has passed. In the meantime, reuse what you have, and try to store rather than throw out items for donation or recycling.
Talk to takeaway food outlets about options for using your own containers, and refuse disposable cutlery or napkins with deliveries. Use the time to upskill your coffee-making at home rather than buying it in a takeaway cup. And look for grocery suppliers offering more sustainable delivery packaging, such as cardboard boxes or biodegradable bags.
Above all, be vigilant about ways environmental protections such as plastic bag bans might be undermined during the pandemic, and voice your concerns to politicians.
This “missing” plastic has been a longstanding scientific question. To date, the search has focused on oceanic gyres such as the Great Pacific Garbage Patch, the water column (the part of the ocean between the surface and the sea bed), the bottom of the ocean, and the stomachs of marine wildlife.
But our new research suggests ocean plastic is being transported back onshore and pushed permanently onto land away from the water’s edge, where it often becomes trapped in vegetation.
Of course, plastic has been reported on beaches around the world for decades. But there has been little focus on why and how coastal environments are a sink for marine debris. Our findings have big implications for how we tackle ocean plastic.
The hunt for marine pollution
Our separate, yet-to-be-published research has found around 90% of marine debris that enters the ocean remains in the “littoral zone” (the area of ocean within 8km of the coast). This new study set out to discover what happens to it.
We collected data on the amount and location of plastic pollution every 100 kilometres around the entire coast of Australia between 2011 and 2016. Debris was recorded at 188 locations along the Australian coastline. Of this, 56% was plastic, followed by glass (17%) and foam (10%).
The debris was a mix of litter from people and deposition from the ocean. The highest concentrations of plastic pollution were found along coastal backshores – areas towards the inland edge of the beach, where the vegetation begins. The further back from the water’s edge we went, the more debris we found.
The amount of marine debris, and where it ends up, is influenced by onshore wave activity and, to a lesser extent, wind activity. Densely populated areas and those where the coast was easily accessible were hotspots for trapped plastics.
Think about what you see on your beach. Smaller debris is often found near the water’s edge, while larger items such as drink bottles, plastic bags and crisp packets are often found further back from the water, often trapped in vegetation.
We also found more debris near urban areas where rivers and creeks enter the ocean. It could be that our trash is being trapped by waterways before it gets to the sea. We’re finding similar patterns in other countries we’re surveying around the Asia Pacific and beyond.
This pollution kills and maims wildlife when they mistake it for food or get tangled in it. It can damage fragile marine ecosystems by smothering sensitive reefs and transporting invasive species and is potentially a threat to human health if toxins in plastics make their way through the food chain to humans.
Our findings highlight the importance of studying the entire width of coastal areas to better understand how much, and where, debris gets trapped, to inform targeted approaches to managing all this waste.
Plastic pollution can be reduced through local changes such as water refill stations, rubbish bins, incentives and awareness campaigns. It can also be reduced through targeted waste management policies to reduce, reuse and recycle plastics. We found container deposit schemes to be a particularly effective incentive in reducing marine pollution.
This discussion is particularly timely. The National Plastics Summit in Canberra last week brought together governments, industry and non-government organisations to identify new solutions to the plastic waste challenge, and discuss how to meet targets under the National Waste Policy Action Plan. Understanding that so much of our debris remains local, and trapped on land, provides real opportunities for successful management of our waste close to the source. This is particularly critical given the waste export ban starting July 1 at the latest.
Plastic in our oceans is increasing. It’s clear from our research that waste management strategies on land must accommodate much larger volumes of pollution than previously estimated. But the best way to keep plastic from our ocean and land is to stop putting it in.
Arianna Olivelli contributed to this article, and the research upon which it was based.
The Morrison government will use its procurement policy to encourage the recycling of plastics, as well as committing financial assistance for upgrading infrastructure to boost the capacity for this waste to be reused.
Scott Morrison will announce the initiatives to a national conference in Canberra on Monday that is looking at the challenge of dealing with this escalating and environmentally destructive problem. The meeting is attended by industry, government and community representatives.
The prime minister, who has previously highlighted better management of plastics waste as a priority for his government, will emphasise that for major change “the only way forward is in partnership – working with our neighbours; state, territory and local governments; industry, our manufacturing sector and supermarkets; waste operators, and with consumers and communities”.
In a speech circulated ahead of delivery he proposes “three pillars” for tackling the problem: taking responsibility for the waste; encouraging demand for recycled products; and expanding industry capability.
Plastics “are choking our oceans. Scientists estimate that in just 30 years’ time the weight of plastics in our oceans will exceed the weight of fish in our oceans. That’s appalling.
“Taking responsibility means recognising the problems we are contributing to – and it also means keeping faith with the Australian people who recycle,” Morrison says.
“Only 12% of plastic put out in the yellow bin for recycling is actually recycled. Australians don’t expect their waste to be exported to someone’s village or waterway.”
Morrison will meet state and territory leaders at the Council of Australian Governments (COAG) next month to finalise a ban on the export of waste plastic, paper, glass and tyres.
He stresses this isn’t to ban the export of value-added recyclable materials.
Morrison says more investment is much needed in the recycling industry; this and collection systems are under “severe strain”. Investment is needed in “technological innovation that maximises the value of the recycled product and minimises the costs as well”. Only 8% of the $2.6 billion states and territories collected in waste levies over 2018-19 has been reinvested in infrastructure and technology.
“The Commonwealth stands ready to co-invest in these critical facilities with state and territory governments, and with industry”, he says. “We will invest with governments and with industry on a 1 to 1 to 1 basis.” Details will come closer to the May budget, Morrison said.
The waste sector employs 50,000 and generates more than $15 billion annually, Morrison says.
“For every 10,000 tonnes of waste sent to landfill, 2.8 direct jobs are created. But if we recycle the same waste, 9.2 direct jobs are created.
“According to the Australian Council of Recycling, recycling more domestically could create more than 5,000 new jobs.”
With a ban on waste plastic being exported, there will be more in Australia to reuse – which means finding ways of encouraging demand for recycled products. Both industry and government need to do this, Morrison says.
As the first of a number of measures the government will take, its procurement guidelines will be rewritten “to make sure every procurement undertaken by a Commonwealth agency considers environmental sustainability and use of recycled content as a factor in determining value for money”.
He instanced a number of examples of innovative recycling, These included “recycled plastic into asphalt … a one kilometre, two-lane stretch [of road] uses up to half a million plastic bags”, as well as into picnic tables, bollards and gardening products.
There are two big problems – particularly since the China ban.
One is about supply. The quality of materials we have for recycling is quite poor, partly from the design of the products, and partly how we collect and sort waste items.
The other is demand. There’s not enough demand for recycled materials in new products or infrastructure, and so the commodity value of the materials, even high quality, is low.
And even though many of us think we’re good at recycling, many households aren’t getting recycling exactly right because they put things that don’t belong in the recycling bin, such as soft plastics.
One reason is because of the confusion about what can be recycled, where and when. A standardised system of collection (no matter how many bins) will go a long way to improving this, and the most exciting aspect of the Victorian announcement is the strong leadership towards consistency across the state.
This means by 2030, no matter where Victorians live or visit, they’ll have a consistent kerbside bin system.
But to boost our recycling capacity, we need consistency across the country. New South Wales, South Australian and Western Australian governments are already supporting combined food and garden organics bins, and other states are likely to follow as the evidence of the benefits continues to accumulate.
What will change?
Details are still being ironed out, but essentially, the new system expands the current two or three bins most Victorian houses have to four bins.
While paper, cardboard and plastic or metal containers will still go in the yellow bin, glass containers will now have their own separate purple bin (or crate). A green bin, which some Victorians already have for garden vegetation, will expand to collect food scraps.
The purple bin will come first, with the gradual roll-out starting next year as some Victorian councils’ existing collection contracts come to a close. The service is expected to be fully in place by 2027 (some remote areas may be exempt).
And the expanded green bin service accepting food scraps for composting will be rolled out by 2030, unless councils choose to move earlier (some are already doing so).
How extra bins will make a difference
A 2015 report on managing household waste in Europe showed separating our waste increases the quality of material collected. Some countries even have up to six bins (or crates, or sacks).
That’s because it’s easier for people to sort out the different materials than for machines, particularly food and the complex packaging we have today.
To make sure the transition to the new system is smooth, councils and the Victorian government must consider:
the space needed for four bins
Not everyone has enough space (inside or outside). This may require creative council and household solutions like those already found overseas (stackable crates and segregated bins).
the collection schedule
Does the new purple bin mean we’ll see a another truck, or perhaps a special multi-compartment recycling truck? And once councils have food waste in a weekly green bin, will the red bin collection go fortnightly? This actually makes sense because 35–60% of the red bin is food scraps, which will be gone.
correct disposal of food waste
Many councils that have already added food waste to the green bin report contamination issues as people get their head around the transition, such as putting food wrappers in with the food scraps.
correct sorting of recycling
Putting the wrong thing in the recycling bin is a problem across the country, and taking glass out of the yellow bin won’t solve this issue. While this is already being tackled in government campaigns and council trials, we’ll likely need more government effort at both a systems and household level.
Better collection won’t mean much without demand
Collection is only one piece of the puzzle. Government support is needed to make sure all this recycling actually ends up somewhere. Efforts to improve the “supply-side” aspects of recycling can go to waste if there’s no demand for the recycled materials.
Environmental economists have long pointed out that without government intervention, free markets in most countries will not pay enough or use enough recycled material when new, or “virgin”, materials are so cheap.
What’s great for Victoria is the new four bin system is only one pillar of the state’s new recycling policy.
It also includes many demand-side initiatives, from market development grants and infrastructure funding, to developing a Circular Economy Business Innovation Centre. The policy also deems waste management to be an “essential service” and has left space for strong procurement commitments. Today, Prime Minister Scott Morrison acknowledged the importance of procurement when he announced an overhaul of the Commonwealth Procurement Guidelines at the National Plastics Summit, to boost demand for recycled products.
Since 2018 when China stopped taking most of our recycling, the level of industry, community and media interest has created a strong platform for policy change. It’s exciting to see Victoria responding to the challenge.
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I was in Switzerland recently and discovered that they haven’t had any landfill since the early 2000s, because all of their waste is either recycled or incinerated to produce electricity. How “green” is it to incinerate waste in order to produce electricity? Is it something New Zealand should consider, so that 1) we have no more landfill, and 2) we can replace our fossil-fuel power stations with power stations that incinerate waste?
Burning rubbish to generate electricity or heat sounds great: you get rid of all your waste and also get seemingly “sustainable” energy. What could be better?
Many developed countries already have significant “waste-to-energy” incineration plants and therefore less material going to landfill (although the ash has to be landfilled). These plants often have recycling industries attached to them, so that only non-recyclables end up in the furnace. If it is this good, why the opposition?
Here are seven reasons why caution is needed when considering waste-to-energy incineration plants.
Waste-to-energy plants require a high-volume, guaranteed waste stream for about 25 years to make them economically viable. If waste-to-energy companies divert large amounts of waste away from landfills, they need to somehow get more waste to maintain their expensive plants. For example, Sweden imports its waste from the UK to feed its “beasts”.
The waste materials that are easiest to source and have buyers for recycling – like paper and plastic – also produce most energy when burned.
Waste-to-energy destroys innovation in the waste sector. As a result of China not accepting our mixed plastics, people are now combining plastics with asphalt to make roads last longer and are making fence posts that could be replacing treated pine posts (which emit copper, chrome and arsenic into the ground). If a convenient waste-to-energy plant had been available, none of this would have happened.
Waste-to-energy reduces jobs. Every job created in the incineration industry removes six jobs in landfill, 36 jobs in recycling and 296 jobs in the reuse industry.
Waste-to-energy works against a circular economy, which tries to keep goods in circulation. Instead, it perpetuates our current make-use-dispose mentality.
Waste-to-energy only makes marginal sense in economies that produce coal-fired electricity – and then only as a stop-gap measure until cleaner energy is available. New Zealand has a green electricity generation system, with about 86% already coming from renewable sources and a target of 100% renewable by 2035, so waste-to-energy would make it a less renewable energy economy.
Lastly, burning waste and contaminated plastics creates a greater environmental impact than burning the equivalent oil they are made from. These impacts include the release of harmful substances like dioxins and vinyl chloride as well as mixtures of many other harmful substances used in making plastics, which are not present in oil.
European countries were driven to waste-to-energy as a result of a 2007 directive that imposed heavy penalties for countries that did not divert waste from landfills. The easiest way for those countries to comply was to install waste-to-energy plants, which meant their landfill waste dropped dramatically.
New Zealand does not have these sorts of directives and is in a better position to work towards reducing, reusing and recycling end-of-life materials, rather than sending them to an incinerator to recover some of the energy used to make them.
Is New Zealand significantly worse than Europe in managing waste? About a decade ago, a delegation from Switzerland visited New Zealand Ministry for the Environment officials to compare progress in each of the waste streams. Both parties were surprised to learn that they had managed to divert roughly the same amount of waste from landfill through different routes.
This shows that it is important New Zealand doesn’t blindly follow the route other countries have used and hope for the same results. Such is the case for waste-to-energy.
There is also an argument to be made for current landfills. Modern, sanitary landfills seal hazardous materials and waste stored over the last 50 years presents future possibilities of landfill mining.
Since the Chinese market closed, 58% of New Zealand’s plastic waste now goes to Malaysia, Indonesia, the Philippines, Thailand and Vietnam — all countries with weak regulations and high rankings as global sources of marine plastic pollution.
Several New Zealand councils have stopped collecting certain plastics for recycling offshore. They are sending them to landfill instead. Available data suggest that even before the China ban plastics made up roughly 15% of the waste in municipal landfills – about 250,000 tonnes a year. Much of this is imported plastic packaging.
In the scramble to find alternatives, waste-to-energy (WtE) incineration has become a hot topic, particularly as foreign investors look to establish WtE incinerators on the West Coast and [other centres]in New Zealand. Some local government representatives have endorsed WtE proposals, or raised WtE as an election issue.
Less plastic good for climate
Like landfills, WtE incinerators symbolise the linear “take-make-waste” economy, which destroys valuable resources and perpetuates waste generation.
Globally, countries are moving to circular approaches instead, which follow the “zero waste hierarchy”. This prioritises waste prevention, reduction, reuse, recycling and composting and considers WtE unacceptable.
Some New Zealanders say Nordic countries have proven that incineration is the environmental silver bullet to our waste woes. But a recent study found these countries will not meet EU circular economy goals unless they replace WtE incineration with policies that reduce waste generation. Such policies include packaging taxes, recycling and recovery rate targets, landfill bans on biodegradable waste, deposit return schemes and extended producer responsibility.
To address plastic pollution, it is easy to see how prevention and reduction work better than “getting rid of” plastic once produced. Many WtE proponents argue that incineration technology can be a temporary solution for the plastic waste we have already created.
The only real solution to our plastics problem is through regulation that moves New Zealand towards a circular economy. We can start by making the linear economy expensive by increasing landfill levies above the current $NZ10/tonne and expanding it to all landfills. We must also invest in better waste collection, sorting and recycling systems, including a national network of resource recovery centres.
Instead of burning or burying plastic that cannot be reused, recycled or composted, we can prevent or reduce it through targeted phase-outs. The government is proposing to regulate single-use plastic packaging, beverage packaging, electronic waste and farm plastics through mandatory product stewardship schemes. This would make manufacturers responsible for the waste they produce and provide incentives for less wasteful and toxic product design and delivery systems (e.g. refill stations).
Without a swift, brave shift to a circular economy, New Zealand will remain one of the world’s most wasteful nations. Circular economies are developing globally and WtE incineration will only set us back by 30 years.
Hannah Blumhardt, the coordinator of the NZ Product Stewardship Council, has contributed to this article.