14 billion litres of untreated wastewater is created each day in developing countries, but we don’t know where it all goes



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Jacqueline Thomas, University of Sydney

To limit the spread of disease and reduce environmental pollution, human waste (excreta) needs to be safely contained and effectively treated. Yet 4.2 billion people, more than half of the world’s population, lack access to safe sanitation.

In developing countries, each person produces, on average, six litres of toilet wastewater each day. Based on the number of people who don’t have access to safe sanitation, that equates to nearly 14 billion litres of untreated faecally contaminated wastewater created each day. That’s the same as 5,600 Olympic-sized swimming pools.

This untreated wastewater directly contributes to increased diarrhoeal diseases, such as cholera, typhoid fever and rotavirus. Diseases such as these are responsible for 297,000 deaths per year of children under five years old, or 800 children every day.

The highest rates of diarrhoea-attributable child deaths are experienced by the poorest communities in countries including Afghanistan, India, and the Democratic Republic of Congo.

Given the global scale of this problem, it’s surprising sanitation practitioners still don’t know where exactly all the human excreta flows or leaches to, due to absent or unreliable data.

Poor sanitation to worsen under climate change

Inadequate sanitation is not only a human health issue, it’s also bad for the environment. An estimated 80% of wastewater from developed and developing countries flows untreated into environments around the world.

If an excess of nutrients (such as nitrogen and phosphorous) are released into the environment from untreated wastewater, it can foul natural ecosystems and disrupt aquatic life.




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This is especially the case for coral reefs. Many of the worlds most diverse coral reefs are located in tropical developing countries.

And overwhelmingly, developing countries have very limited human excreta management, leading to large quantities of raw wastewater being released directly onto coral reefs. In countries with high populations such as Indonesia and the Philippines, this is particularly evident.

A coral reef underwater, with clown fish swimming by.
Sewage discharges in proximity to sensitive coral reefs, particularly in the tropics.
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The damage raw wastewater inflicts on corals is severe. Raw wastewater carries solids, endocrine disrupters (chemicals that interfere with hormones), inorganic nutrients, heavy metals and pathogens directly to corals. This stunts coral growth, causes more coral diseases and reduces their reproduction rates.

The challenges of climate change will exacerbate our sanitation crisis, as increased rain and flooding will inundate sanitation systems and cause them to overflow. Pacific Island nations are particularly vulnerable, because of the compounding impacts of rising sea levels and more frequent, extreme tropical cyclones.

Meanwhile, increased drought and severe water scarcity in other parts of the world will render some sanitation systems, such as sewer systems, inoperable. One example is the mismanagement of government-operated water supplies in Harare, Zimbabwe leading to the failure of the sewerage system and placing millions at risk of waterborne diseases.

Even in more developed countries like Australia, increased frequency of extreme weather events and disasters, including bushfires, will damage some sanitation infrastructure beyond repair.

Global targets to improve sanitation

Improving clean water and sanitation have clear global targets. Goal 6 of the United Nation’s sustainable development goals is to, by 2030, achieve adequate and equitable sanitation for all and to halve the proportion of untreated wastewater.

A man emptying a pit latrine in urban Tanzania
A man emptyies a pit latrine in urban Tanzania.
Jacqueline Thomas, Author provided

Achieving this target will be difficult, given there is an absence of reliable data on the exact numbers of sanitation systems that are safely managed or not, particularly in developing countries.

Individual studies in countries such as Tanzania provide small amounts of information on whether some sanitation systems are safely managed. But these studies are not yet at the size needed to extrapolate to national scales.




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So what’s behind this lack of data?

A big reason behind the missing data is the large range of sanitation systems and their complex classifications.

For example, in developing countries, most people are serviced by on-site sanitation such as septic tanks (a concrete tank) or pit latrines (hole dug into the ground). But a lack of adherence to construction standards in nearly all developing countries, means most septic tanks are not built to standard and do not safely contain or treat faecal sludge.

A hole in the ground, lined with two bricks, and a blue bucket beside it
A typical pit latrine in rural Tanzania.
Jacqueline Thomas, Author provided

A common example seen with septic tank construction is there are a lot of incentives to build “non-standard” septic tanks that are much cheaper. From my current research in rural Fiji, I’ve seen reduced tank sizes and the use of alternative materials (old plastic water tanks) to save space and money in material costs.

These don’t allow for adequate containment or treatment. Instead, excreta can leach freely into the surrounding environment.

A white pipe juts out of a blue plastic tank and into the ground.
A ‘non-standard’ septic tank, which uses plastic, in Fiji.
Jacqueline Thomas, Author provided

A standard septic tank is designed to be desludged periodically, where the settled solids at the bottom of the tanks are removed by large vacuum trucks and disposed of safely. So, having a non-standard septic tank is further incentivised as the lack of sealed chambers reduces the accumulation of sludge, delaying costly emptying fees.

Another key challenge with data collection is how to determine if the sanitation infrastructure if functioning correctly. Even if the original design was built to a quality standard, in many circumstances there are significant deficiencies in operational and maintenance activities that lead to the system not working properly.




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What’s more, terminology is a constant point of confusion. Households — when surveyed for UN’s Sustainable Development Goal data collection on sanitation — will say they do have a septic tank. But in reality, they’re unaware they have a non-standard septic tank functioning as a leach-pit, and not safely treating or containing their excreta.

Fixing the problem

Achieving the Sustainable Development Goal 6 requires nationally representative data sets. The following important questions must be answered, at national scales in developing countries:

  • for every toilet, where does the excreta go? Is it safely contained, treated on site, or transported for treatment?

  • if the excreta is not contained or treated properly after it leaves the toilet, then how far does it travel through the ground or waterways?

  • when excreta is removed from the pit or septic tank of a full on-site latrine, where is it taken? Is it dumped in the environment or safely treated?

  • are sewer systems intact and connected to functioning wastewater treatment plants that releases effluent (treated waste) of a safe quality?

Presently, the sanitation data collection tools the UN uses for its Sustainable Development Goals don’t answer in full these critical questions. More robust surveys and sampling programs need to be designed, along with resource allocation for government sanitation departments for a more thorough data collection strategy.

And importantly, we need a co-ordinated investment in sustainable sanitation solutions from all stakeholders, especially governments, international organisations and the private sector. This is essential to both protect the health of our own species and all other living things.




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The Conversation


Jacqueline Thomas, Lecturer in Environmental and Humanitarian Engineering, University of Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

These are the plastic items that most kill whales, dolphins, turtles and seabirds



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Lauren Roman, CSIRO; Britta Denise Hardesty, CSIRO; Chris Wilcox, CSIRO, and Qamar Schuyler, CSIRO

How do we save whales and other marine animals from plastic in the ocean? Our new review shows reducing plastic pollution can prevent the deaths of beloved marine species. Over 700 marine species, including half of the world’s cetaceans (such as whales and dolphins), all of its sea turtles and a third of its seabirds, are known to ingest plastic.

When animals eat plastic, it can block their digestive system, causing a long, slow death from starvation. Sharp pieces of plastic can also pierce the gut wall, causing infection and sometimes death. As little as one piece of ingested plastic can kill an animal.

About eight million tonnes of plastic enters the ocean each year, so solving the problem may seem overwhelming. How do we reduce harm to whales and other marine animals from that much plastic?

Like a hospital overwhelmed with patients, we triage. By identifying the items that are deadly to the most vulnerable species, we can apply solutions that target these most deadly items.

Some plastics are deadlier than others

In 2016, experts identified four main items they considered to be most deadly to wildlife: fishing debris, plastic bags, balloons and plastic utensils.

We tested these expert predictions by assessing data from 76 published research papers incorporating 1,328 marine animals (132 cetaceans, 20 seals and sea lions, 515 sea turtles and 658 seabirds) from 80 species.

We examined which items caused the greatest number of deaths in each group, and also the “lethality” of each item (how many deaths per interaction). We found the experts got it right for three of four items.

Plastic bag floats in the ocean.
Film plastics cause the most deaths in cetaceans and sea turtles.
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Flexible plastics, such as plastic sheets, bags and packaging, can cause gut blockage and were responsible for the greatest number of deaths over all animal groups. These film plastics caused the most deaths in cetaceans and sea turtles. Fishing debris, such as nets, lines and tackle, caused fatalities in larger animals, particularly seals and sea lions.

Turtles and whales that eat debris can have difficulty swimming, which may increase the risk of being struck by ships or boats. In contrast, seals and sea lions don’t eat much plastic, but can die from eating fishing debris.

Balloons, ropes and rubber, meanwhile, were deadly for smaller fauna. And hard plastics caused the most deaths among seabirds. Rubber, fishing debris, metal and latex (including balloons) were the most lethal for birds, with the highest chance of causing death per recorded ingestion.




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What’s the solution?

The most cost-efficient way to reduce marine megafauna deaths from plastic ingestion is to target the most lethal items and prioritise their reduction in the environment.

Targeting big plastic items is also smart, as they can break down into smaller pieces. Small debris fragments such as microplastics and fibres are a lower management priority, as they cause significantly fewer deaths to megafauna and are more difficult to manage.

Image of dead bird and gloved hand containing small plastics.
Plastic found in the stomach of a fairy prion.
Photo supplied by Lauren Roman

Flexible film-like plastics, including plastic bags and packaging, rank among the ten most common items in marine debris surveys globally. Plastic bag bans and fees for bags have already been shown to reduce bags littered into the environment. Improving local disposal and engineering solutions to enable recycling and improve the life span of plastics may also help reduce littering.

Lost fishing gear is particularly lethal. Fisheries have high gear loss rates: 5.7% of all nets and 29% of all lines are lost annually in commercial fisheries. The introduction of minimum standards of loss-resistant or higher quality gear can reduce loss.




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Other steps can help, too, including

  • incentivising gear repairs and port disposal of damaged nets

  • penalising or prohibiting high-risk fishing activities where snags or gear loss are likely

  • and enforcing penalties associated with dumping.

Outreach and education to recreational fishers to highlight the harmful effects of fishing gear could also have benefit.

Balloons, latex and rubber are rare in the marine environment, but are disproportionately lethal, particularly to sea turtles and seabirds. Preventing intentional balloon releases and accidental release during events and celebrations would require legislation and a shift in public will.

The combination of policy change with behaviour change campaigns are known to be the most effective at reducing coastal litter across Australia.

Reducing film-like plastics, fishing debris and latex/balloons entering the environment would likely have the best outcome in directly reducing mortality of marine megafauna.




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The Conversation


Lauren Roman, Postdoctoral Researcher, Oceans and Atmosphere, CSIRO; Britta Denise Hardesty, Principal Research Scientist, Oceans and Atmosphere Flagship, CSIRO; Chris Wilcox, Senior Principal Research Scientist, CSIRO, and Qamar Schuyler, Research Scientist, Oceans and Atmospheres, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

It might be the world’s biggest ocean, but the mighty Pacific is in peril



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Jodie L. Rummer, James Cook University; Bridie JM Allan, University of Otago; Charitha Pattiaratchi, University of Western Australia; Ian A. Bouyoucos, James Cook University; Irfan Yulianto, IPB University, and Mirjam van der Mheen, University of Western Australia

The Pacific Ocean is the deepest, largest ocean on Earth, covering about a third of the globe’s surface. An ocean that vast may seem invincible. Yet across its reach – from Antarctica in the south to the Arctic in the north, and from Asia to Australia to the Americas – the Pacific Ocean’s delicate ecology is under threat.

In most cases, human activity is to blame. We have systematically pillaged the Pacific of fish. We have used it as a rubbish tip – garbage has been found even in the deepest point on Earth, in the Mariana Trench 11,000 metres below sea level.

And as we pump carbon dioxide into the atmosphere, the Pacific, like other oceans, is becoming more acidic. It means fish are losing their sense of sight and smell, and sea organisms are struggling to build their shells.

Oceans produce most of the oxygen we breathe. They regulate the weather, provide food, and give an income to millions of people. They are places of fun and recreation, solace and spiritual connection. So, healthy, vibrant oceans benefit us all. And by better understanding the threats to the precious Pacific, we can start the long road to protecting it.


This article is part of the Oceans 21 series

The series opens with five profiles delving into ancient Indian Ocean trade networks, Pacific plastic pollution, Arctic light and life, Atlantic fisheries and the Southern Ocean’s impact on global climate. It’s brought to you by The Conversation’s international network.


The ocean plastic scourge

The problem of ocean plastic was scientifically recognised in the 1960s after two scientists saw albatross carcasses littering the beaches of the northwest Hawaiian Islands in the northern Pacific. Almost three in four albatross chicks, who died before they could fledge, had plastic in their stomachs.

Now, plastic debris is found in all major marine habitats around the world, in sizes ranging from nanometers to meters. A small portion of this accumulates into giant floating “garbage patches”, and the Pacific Ocean is famously home to the largest of them all.

Most plastic debris from land is transported into the ocean through rivers. Just 20 rivers contribute two-thirds of the global plastic input into the sea, and ten of these discharge into the northern Pacific Ocean. Each year, for example, the Yangtze River in China – which flows through Shanghai – sends about 1.5 million metric tonnes of debris into the Pacific’s Yellow Sea.

A wildlife killer

Plastic debris in the oceans presents innumerable hazards for marine life. Animals can get tangled in debris such as discarded fishing nets, causing them to be injured or drown.

Some organisms, such as microscopic algae and invertebrates, can also hitch a ride on floating debris, travelling large distances across the oceans. This means they can be dispersed out of their natural range, and can colonise other regions as invasive species.




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And of course, wildlife can be badly harmed by ingesting debris, such as microplastics less than five millimetres in size. This plastic can obstruct an animal’s mouth or accumulate in its stomach. Often, the animal dies a slow, painful death.

Seabirds, in particular, often mistake floating plastics for food. A 2019 study found there was a 20% chance seabirds would die after ingesting a single item, rising to 100% after consuming 93 items.

A turtle tangled in a fishing net
Discarded fishing nets, or ‘ghost nets’ can entangle animals like turtles.
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A scourge on small island nations

Plastic is extremely durable, and can float vast distances across the ocean. In 2011, 5 million tonnes of debris entered the Pacific during the Japan tsunami. Some crossed the entire ocean basin, ending up on North American coastlines.

And since floating plastics in the open ocean are transported mainly by ocean surface currents and winds, plastic debris accumulates on island coastlines along their path. Kamilo Beach, on the south-eastern tip of Hawaii’s Big Island, is considered one of the world’s worst for plastic pollution. Up to 20 tonnes of debris wash onto the beach each year.

Similarly, on uninhabited Henderson Island, part of the Pitcairn Island chain in the south Pacific, 18 tonnes of plastic have accumulated on a beach just 2.5km long. Several thousand pieces of plastic wash up each day.

Kamilo Beach is referred to as the world’s dirtiest.

Subtropical garbage patches

Plastic waste can have different fates in the ocean: some sink, some wash up on beaches and some float on the ocean surface, transported by currents, wind and waves.

Around 1% of plastic waste accumulates in five subtropical “garbage patches” in the open ocean. They’re formed as a result of ocean circulation, driven by the changing wind fields and the Earth’s rotation.

There are two subtropical garbage patches in the Pacific: one in the northern and one in the southern hemisphere.

The northern accumulation region is separated into an eastern patch between California and Hawaii, and a western patch, which extends eastwards from Japan.

Locations of the five subtropical garbage patches.
van der Mheen et al. (2019)

Our ocean garbage shame

First discovered by Captain Charles Moore in the early 2000s, the eastern patch is better known as the Great Pacific Garbage Patch because it’s the largest by both size (around 1.6 million square kilometers) and amount of plastic. By weight, this garbage patch can hold more than 100 kilograms per square kilometre.

The garbage patch in the southern Pacific is located off Valparaiso, Chile, extending to the west. It has lower concentrations compared to its giant counterpart in the northeast.

Discarded fishing nets make up around 45% of the total plastic weight in the Great Pacific Garbage Patch. Waste from the 2011 Japan tsunami is also a major contributor, making up an estimated 20% of the patch.




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With time, larger plastic debris degrades into microplastics. Microplastics form only 8% of the total weight of plastic waste in the Great Pacific Garbage Patch, but make up 94% of the estimated 1.8 trillion pieces of plastic there. In high concentrations, they can make the water “cloudy”.

Each year, up to 15 million tonnes of plastic waste are estimated to make their way into the ocean from coastlines and rivers. This amount is expected to double by 2025 as plastic production continues to increase.

We must act urgently to stem the flow. This includes developing plans to collect and remove the plastics and, vitally, stop producing so much in the first place.

Divers releasing a whale shark from a fishing net.

Fisheries on the verge of collapse

As the largest and deepest sea on Earth, the Pacific supports some of the world’s biggest fisheries. For thousands of years, people have relied on these fisheries for their food and livelihoods.

But, around the world, including in the Pacific, fishing operations are depleting fish populations faster than they can recover. This overfishing is considered one of the most serious threats to the world’s oceans.

Humans take about 80 million tonnes of wildlife from the sea each year. In 2019, the world’s leading scientists said of all threats to marine biodiversity over the past 50 years, fishing has caused the most harm. They said 33% of fish species were overexploited, 60% were being fished to the maximum level, and just 7% were underfished.

The decline in fish populations is not just a problem for humans. Fish play an important role in marine ecosystems and are a crucial link in the ocean’s complex food webs.

A school of fish
Overfishing is stripping the Pacific Ocean of marine life.
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Not plenty of fish in the sea

Overfishing happens when humans extract fish resources beyond the maximum level, known as the “maximum sustainable yield”. Fishing beyond this causes global fish stocks to decline, disrupts food chains, degrades habitats, and creates food scarcity for humans.

The Pacific Ocean is home to huge tuna fisheries, which provide almost 65% of the global tuna catch each year. But the long-term survival of many tuna populations is at risk.

For example, a study released in 2013 found numbers of bluefin tuna – a prized fish used to make sushi – had declined by more than 96% in the Northern Pacific Ocean.

Developing countries, including Indonesia and China, are major overfishers, but so too are developing nations.




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Along Canada’s west coast, Pacific salmon populations have declined rapidly since the early 1990s, partly due to overfishing. And Japan was recently heavily criticised for a proposal to increase quotas on Pacific bluefin tuna, a species reportedly at just 4.5% of its historic population size.

Experts say overfishing is also a problem in Australia. For example, research in 2018 showed large fish species were rapidly declining around the nation due to excessive fishing pressure. In areas open to fishing, exploited populations fell by an average of 33% in the decade to 2015.

A plate of sushi
Stocks of fish used to make sushi have declined in number.
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So what’s driving overfishing?

There are many reasons why overfishing occurs and why it is goes unchecked. The evidence points to:




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Let’s take Indonesia as an example. Indonesia lies between the Pacific and Indian oceans and is the world’s third-biggest producer of wild-capture fish after China and Peru. Some 60% of the catch is made by small-scale fishers. Many hail from poor coastal communities.

Overfishing was first reported in Indonesia in the 1970s. It prompted a presidential decree in 1980, banning trawling off the islands of Java and Sumatra. But overfishing continued into the 1990s, and it persists today. Target species include reef fishes, lobster, prawn, crab, and squid.

Indonesia’s experience shows how there is no easy fix to the overfishing problem. In 2017, the Indonesian government issued a decree that was supposed to keep fishing to a sustainable level – 12.5 million tonnes per year. Yet, in may places, the practice continued – largely because the rules were not clear and local enforcement was inadequate.

Implementation was complicated by the fact that almost all Indonesia’s smaller fishing boats come under the control of provincial governments. This reveals the need for better cooperation between levels of government in cracking down on overfishing.

Man checks fishing haul
Globally, compliance and enforcement of fishing limits is often poor.
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What else can we do?

To prevent overfishing, governments should address the issue of poverty and poor education in small fishing communities. This may involve finding them a new source of income. For example in the town of Oslob in the Philippines, former fishermen and women have turned to tourism – feeding whale sharks tiny amounts of krill to draw them closer to shore so tourists can snorkel or dive with them.

Tackling overfishing in the Pacific will also require cooperation among nations to monitor fishing practices and enforce the rules.

And the world’s network of marine protected areas should be expanded and strengthened to conserve marine life. Currently, less than 3% of the world’s oceans are highly protected “no take” zones. In Australia, many marine reserves are small and located in areas of little value to commercial fishers.

The collapse of fisheries around the world shows just how vulnerable our marine life is. It’s clear that humans are exploiting the oceans beyond sustainable levels. Billions of people rely on seafood for protein and for their livelihoods. But by allowing overfishing to continue, we harm not just the oceans, but ourselves.

fish in a net
Providing fishers with an alternative income can help prevent overfishing.
Shutterstock



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The threat of acidic oceans

The tropical and subtropical waters of the Pacific Ocean are home to more than 75% of the world’s coral reefs. These include the Great Barrier Reef and more remote reefs in the Coral Triangle, such as those in Indonesia and Papua New Guinea.

Coral reefs are bearing the brunt of climate change. We hear a lot about how coral bleaching is damaging coral ecosystems. But another insidious process, ocean acidification, is also threatening reef survival.

Ocean acidification particularly affects shallow waters, and the subarctic Pacific region is particularly vulnerable.

Coral reefs cover less than 0.5% of Earth’s surface, but house an estimated 25% of all marine species. Due to ocean acidification and other threats, these incredibly diverse “underwater rainforests” are among the most threatened ecosystems on the planet.

A chemical reaction

Ocean acidification involves a decrease in the pH of seawater as it absorbs carbon dioxide (CO₂) from the atmosphere.

Each year, humans emit 35 billion tonnes of CO₂ through activities such as burning of fossil fuels and deforestation.

Oceans absorb up to 30% of atmospheric CO₂, setting off a chemical reaction in which concentrations of carbonate ions fall, and hydrogen ion concentrations increase. That change makes the seawater more acidic.

Since the Industrial Revolution, ocean pH has decreased by 0.1 units. This may not seem like much, but it actually means the oceans are now about 28% more acidic than since the mid-1800s. And the Intergovernmental Panel on Climate Change (IPCC) says the rate of acidification is accelerating.

An industrial city from the air
Each year, humans emit 35 billion tonnes of CO₂.
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Why is ocean acidification harmful?

Carbonate ions are the building blocks for coral structures and organisms that build shells. So a fall in the concentrations of carbonate ions can spell bad news for marine life.

In more acidic waters, molluscs have been shown to have trouble making and repairing their shells. They also exhibit impaired growth, metabolism, reproduction, immune function, and altered behaviours. For example, researchers exposed sea hares (a type of sea slug) in French Polynesia to simulated ocean acidification and found they had less foraging success and made poorer decisions.

Ocean acidification is also a problem for the fishes. Many studies have revealed elevated CO₂ can disrupt their sense of smell, vision and hearing. It can also impair survival traits, such as a fish’s ability to learn, avoid predators, and select suitable habitat.

Such impairment appears to be the result of changes in neurological, physiological, and molecular functions in fish brains.

A sea hare
Sea hares exposed to acidification made poorer decisions.
Shutterstock

Predicting the winners and losers

Of the seven oceans, the Pacific and Indian Oceans have been acidifying at the fastest rates since 1991. This suggests their marine life may also be more vulnerable.

However, ocean acidification does not affect all marine species in the same way, and the effects can vary over the organism’s lifetime. So, more research to predict the future winners and losers is crucial.

This can be done by identifying inherited traits that can increase an organism’s survival and reproductive success under more acidic conditions. Winner populations may start to adapt, while loser populations should be targets for conservation and management.




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One such winner may be the epaulette shark, a shallow water reef species endemic to the Great Barrier Reef. Research suggests simulated ocean acidification conditions do not impact early growth, development, and survival of embryos and neonates, nor do they affect foraging behaviours or metabolic performance of adults.

But ocean acidification is also likely to create losers on the Great Barrier Reef. For example, researchers studying the orange clownfish – a species made famous by Disney’s animated Nemo character – found they suffered multiple sensory impairments under simulated ocean acidification conditions. These ranged from difficulties smelling and hearing their way home, to distinguishing friend from foe.

A clownfish
Clownfish struggled to tell friend from foe when exposed to ocean acidification.
Shutterstock

It’s not too late

More than half a billion people depend on coral reefs for food, income, and protection from storms and coastal erosion. Reefs provide jobs – such as in tourism and fishing – and places for recreation. Globally, coral reefs represent an industry worth US$11.9 trillion per year. And importantly, they’re a place of deep cultural and spiritual connection for Indigenous people around the world.

Ocean acidification is not the only threat to coral reefs. Under climate change, the rate of ocean warming has doubled since the 1990s. The Great Barrier Reef, for example, has warmed by 0.8℃ since the Industrial Revolution. Over the past five years this has caused devastating back-to-back coral bleaching events. The effects of warmer seas are magnified by ocean acidification.




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Cutting greenhouse gas emissions must become a global mission. COVID-19 has slowed our movements across the planet, showing it’s possible to radically slash our production of CO₂. If the world meets the most ambitious goals of the Paris Agreement and keeps global temperature increases below 1.5℃, the Pacific will experience far less severe decreases in oceanic pH.

We will, however, have to curb emissions by a lot more – 45% over the next decade – to keep global warming below 1.5℃. This would give some hope that coral reefs in the Pacific, and worldwide, are not completely lost.

Clearly, the decisions we make today will affect what our oceans look like tomorrow.The Conversation

The Pacific Ocean off the Taiwan coast
Our decisions today will determine the fate of tomorrow’s oceans.
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Jodie L. Rummer, Associate Professor & Principal Research Fellow, James Cook University; Bridie JM Allan, Lecturer/researcher, University of Otago; Charitha Pattiaratchi, Professor of Coastal Oceanography, University of Western Australia; Ian A. Bouyoucos, Postdoctoral fellow, James Cook University; Irfan Yulianto, Lecturer of Fisheries Resources Utilization, IPB University, and Mirjam van der Mheen, Fellow, University of Western Australia

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Japan plans to dump a million tonnes of radioactive water into the Pacific. But Australia has nuclear waste problems, too


Tilman Ruff, University of Melbourne and Margaret Beavis

The Japanese government recently announced plans to release into the sea more than 1 million tonnes of radioactive water from the severely damaged Fukushima Daiichi nuclear plant.

The move has sparked global outrage, including from UN Special Rapporteur Baskut Tuncak who recently wrote,

I urge the Japanese government to think twice about its legacy: as a true champion of human rights and the environment, or not.

Alongside our Nobel Peace Prize-winning work promoting nuclear disarmament, we have worked for decades to minimise the health harms of nuclear technology, including site visits to Fukushima since 2011. We’ve concluded Japan’s plan is unsafe, and not based on evidence.

Japan isn’t the only country with a nuclear waste problem. The Australian government wants to send nuclear waste to a site in regional South Australia — a risky plan that has been widely criticised.

Contaminated water in leaking tanks

In 2011, a massive earthquake and tsunami resulted in the meltdown of four large nuclear reactors, and extensive damage to the reactor containment structures and the buildings which house them.

Water must be poured on top of the damaged reactors to keep them cool, but in the process, it becomes highly contaminated. Every day, 170 tonnes of highly contaminated water are added to storage on site.

As of last month, this totalled 1.23 million tonnes. Currently, this water is stored in more than 1,000 tanks, many hastily and poorly constructed, with a history of leaks.

How does radiation harm marine life?

If radioactive material leaks into the sea, ocean currents can disperse it widely. The radioactivity from Fukushima has already caused widespread contamination of fish caught off the coast, and was even detected in tuna caught off California.




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Ionising radiation harms all organisms, causing genetic damage, developmental abnormalities, tumours and reduced fertility and fitness. For tens of kilometres along the coast from the damaged nuclear plant, the diversity and number of organisms have been depleted.

Of particular concern are long-lived radioisotopes (unstable chemical elements) and those which concentrate up the food chain, such as cesium-137 and strontium-90. This can lead to fish being thousands of times more radioactive than the water they swim in.

Failing attempts to de-contaminate the water

In recent years, a water purification system — known as advanced liquid processing — has been used to treat the contaminated water accumulating in Fukushima to try to reduce the 62 most important contaminating radioisotopes.

But it hasn’t been very effective. To date, 72% of the treated water exceeds the regulatory standards. Some treated water has been shown to be almost 20,000 times higher than what’s allowed.




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The cherry trees of Fukushima


One important radioisotope not removed in this process is tritium — a radioactive form of hydrogen with a half-life of 12.3 years. This means it takes 12.3 years for half of the radioisotope to decay.

Tritium is a carcinogenic byproduct of nuclear reactors and reprocessing plants, and is routinely released both into the water and air.

The Japanese government and the reactor operator plan to meet regulatory limits for tritium by diluting contaminated water. But this does not reduce the overall amount of radioactivity released into the environment.

How should the water be stored?

The Japanese Citizens Commission for Nuclear Energy is an independent organisation of engineers and researchers. It says once water is treated to reduce all significant isotopes other than tritium, it should be stored in 10,000-tonne tanks on land.

If the water was stored for 120 years, tritium levels would decay to less than 1,000th of the starting amount, and levels of other radioisotopes would also reduce. This is a relatively short and manageable period of time, in terms of nuclear waste.

Then, the water could be safely released into the ocean.

Nuclear waste storage in Australia

Australians currently face our own nuclear waste problems, stemming from our nuclear reactors and rapidly expanding nuclear medicine export business, which produces radioisotopes for medical diagnosis, some treatments, scientific and industrial purposes.




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This is what happens at our national nuclear facility at Lucas Heights in Sydney. The vast majority of Australia’s nuclear waste is stored on-site in a dedicated facility, managed by those with the best expertise, and monitored 24/7 by the Australian Federal Police.

But the Australian government plans to change this. It wants to transport and temporarily store nuclear waste at a facility at Kimba, in regional South Australia, for an indeterminate period. We believe the Kimba plan involves unnecessary multiple handling, and shifts the nuclear waste problem onto future generations.

The proposed storage facilities in Kimba are less safe than disposal, and this plan is well below world’s best practice.

The infrastructure, staff and expertise to manage and monitor radioactive materials in Lucas Heights were developed over decades, with all the resources and emergency services of Australia’s largest city. These capacities cannot be quickly or easily replicated in the remote rural location of Kimba. What’s more, transporting the waste raises the risk of theft and accident.

And in recent months, the CEO of regulator ARPANSA told a senate inquiry there is capacity to store nuclear waste at Lucas Heights for several more decades. This means there’s ample time to properly plan final disposal of the waste.

The legislation before the Senate will deny interested parties the right to judicial review. The plan also disregards unanimous opposition by Barngarla Traditional Owners.




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The Conversation contacted Resources Minister Keith Pitt who insisted the Kimba site will consolidate waste from more than 100 places into a “safe, purpose-built, state-of-the-art facility”. He said a separate, permanent disposal facility will be established for intermediate level waste in a few decades’ time.

Pitt said the government continues to seek involvement of Traditional Owners. He also said the Kimba community voted in favour of the plan. However, the voting process was criticised on a number of grounds, including that it excluded landowners living relatively close to the site, and entirely excluded Barngarla people.

Kicking the can down the road

Both Australia and Japan should look to nations such as Finland, which deals with nuclear waste more responsibly and has studied potential sites for decades. It plans to spend 3.5 billion euros (A$5.8 billion) on a deep geological disposal site.




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Intermediate level nuclear waste like that planned to be moved to Kimba contains extremely hazardous materials that must be strictly isolated from people and the environment for at least 10,000 years.

We should take the time needed for an open, inclusive and evidence-based planning process, rather than a quick fix that avoidably contaminates our shared environment and creates more problems than it solves.

It only kicks the can down the road for future generations, and does not constitute responsible radioactive waste management.


The following are additional comments provided by Resources Minister Keith Pitt in response to issues raised in this article (comments added after publication):

(The Kimba plan) will consolidate waste into a single, safe, purpose-built, state-of-the-art facility. It is international best practice and good common sense to do this.

Key indicators which showed the broad community support in Kimba included 62 per cent support in the local community ballot, and 100 per cent support from direct neighbours to the proposed site.

In assessing community support, the government also considered submissions received from across the country and the results of Barngarla Determination Aboriginal Corporation’s own vote.

The vast majority of Australia’s radioactive waste stream is associated with nuclear medicine production that, on average, two in three Australians will benefit from during their lifetime.

The facility will create a new, safe industry for the Kimba community, including 45 jobs in security, operations, administration and environmental monitoring.The Conversation

Tilman Ruff, Associate Professor, Education and Learning Unit, Nossal Institute for Global Health, School of Population and Global Health, University of Melbourne and Margaret Beavis, Tutor Principles of Clinical Practice Melbourne Medical School

This article is republished from The Conversation under a Creative Commons license. Read the original article.

We estimate there are up to 14 million tonnes of microplastics on the seafloor. It’s worse than we thought



Shutterstock

Britta Denise Hardesty, CSIRO; Chris Wilcox, CSIRO, and Justine Barrett, CSIRO

Nowhere, it seems, is immune from plastic pollution: plastic has been reported in the high Arctic oceans, in the sea ice around Antarctica and even in the world’s deepest waters of the Mariana Trench.

But just how bad is the problem? Our new research provides the first global estimate of microplastics on the seafloor — our research suggests there’s a staggering 8-14 million tonnes of it.

This is up to 35 times more than the estimated weight of plastic pollution on the ocean’s surface.

What’s more, plastic production and pollution is expected to increase in coming years, despite increased media, government and scientific attention on how plastic pollution can harm marine ecosystems, wildlife and human health.

These findings are yet another wake-up call. When the plastic we use in our daily lives reaches even the deepest oceans, it’s more urgent than ever to find ways to clean up our mess before it reaches the ocean, or to stop making so much of it in the first place.

Breaking down larger plastic

Our estimate of microplastics on the seafloor is huge, but it’s still a fraction of the amount of plastic dumped into the ocean. Between 4-8 million tonnes of plastic are thought to enter the sea each and every year.




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Most of the plastic dumped into the ocean likely ends up on the coasts, not floating around the ocean’s surface or on the seafloor. In fact, three-quarters of the rubbish found along Australia’s coastlines is plastics.

A dead albatross with plastic in its stomach from Midway Atoll
Plastic including toothbrushes, cigarette lighters, bottle caps and other hard plastic fragments are found in the stomachs of many marine species.
Britta Denise Hardesty

The larger pieces of plastic that stay in the ocean can deteriorate and break down from weathering and mechanical forces, such as ocean waves. Eventually, this material turns into microplastics, pieces smaller than 5 millimetres in diameter.

Their tiny size means they can be eaten by a variety of marine wildlife, from plankton to crustaceans and fish. And when microplastics enter the marine food web at low levels, it can move up the food chain as bigger species eat smaller ones.

But the problem isn’t as well documented for microplastics on the seafloor. While plastics, including microplastics, have been found in deep-sea sediments in all ocean basins across the world, samples have been small and scarce. This is where our research comes in.

Collecting samples in the Great Australian Bight

We collected samples using a robotic submarine in a range of sea depths, from 1,655 to 3,062 metres, in the Great Australian Bight, up to 380 kilometres offshore from South Australia. The submarine scooped up 51 samples of sand and sediment from the seafloor and we analysed them in a laboratory.

Sampling of deep sea sediments took place using an underwater robot.
CSIRO, Author provided

We dried the sediment samples, and found between zero and 13.6 plastic particles per gram. This is up to 25 times more microplastics than previous deep-sea studies. And it’s much higher than studies in other regions, including in the Arctic and Indian Oceans.

While our study looked at one general area, we can scale up to calculate a global estimate of microplastics on the seafloor.

Using the estimated size of the entire ocean — 361,132,000 square kilometres — and the average number and size of particles in our sediment samples, we determined the total, global weight as between 8.4 and 14.4 million tonnes. This range takes into account the possible weights of individual microplastics.

How did the plastic get there?

It’s important to note that since our location was remote, far from any urban population centre, this is a conservative estimate. Yet, we were surprised at just how high the microplastic loads were there.

Plastic waste floating in the ocean
Areas with floating rubbish on the ocean’s surface have plastic on the seafloor.
Shutterstock

Few studies have conclusively identified how microplastics travel to their ultimate fate.

Larger pieces of plastic that get broken down to smaller pieces can sink to the seafloor, and ocean currents and the natural movement of sediment along continental shelves can transport them widely.

But not all plastic sinks. A 2016 study suggests interaction with marine organisms is another possible transport method.

Scientists in the US have shown microbial communities, such as bacteria, can inhabit this marine “plastisphere” — a term for the ecosystems that live in plastic environments. The microbes weigh the plastic down so it no longer floats. We also know mussels and other invertebrates may colonise floating plastics, adding weight to make them sink.




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The type of rubbish will also determine whether it gets washed up on the beach or sinks to the seafloor.

For example, in a previous study we found cigarette butts, plastic fragments, bottlecaps and food wrappers are common on land, though rare on the seabed. Meanwhile, we found entangling items such fishing line, ropes and plastic bags are common on the seafloor.

Microplastics at the water's edge
We were surprised at just how high the microplastic loads were in such a remote location.
CSIRO

Interestingly, in our new study we also found the number of plastic fragments on the seafloor was generally higher in areas where there was floating rubbish on the ocean’s surface. This suggests surface “hotspots” may be reflected below.

It’s not clear why just yet, but it could be because of the geology and physical features of the seabed, or because local currents, winds and waves result in accumulating zones on the ocean’s surface and the seabed nearby.

Stop using so much plastic

Knowing how much plastic sinks to the ocean floor is an important addition to our understanding of the plastic pollution crisis. But stemming the rising tide of plastic pollution starts with individuals, communities and governments – we all have a role to play.

Reusing, refusing and recycling are good places to start. Seek alternatives and support programs, such as Clean Up Australia Day, to stop plastic waste from entering our environment in the first place, ensuring it doesn’t then become embedded in our precious oceans.




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The Conversation


Britta Denise Hardesty, Principal Research Scientist, Oceans and Atmosphere Flagship, CSIRO; Chris Wilcox, Senior Principal Research Scientist, CSIRO, and Justine Barrett, Research assistant, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

A brutal war and rivers poisoned with every rainfall: how one mine destroyed an island



Locals living downstream of the abandoned mine pan for gold in mine waste.
Matthew Allen, Author provided

Matthew G. Allen, The University of the South Pacific

This week, 156 people from the Autonomous Region of Bougainville, in Papua New Guinea, petitioned the Australian government to investigate Rio Tinto over a copper mine that devastated their homeland.

In 1988, disputes around the notorious Panguna mine sparked a lengthy civil war in Bougainville, leading to the deaths of up to 20,000 people. The war is long over and the mine has been closed for 30 years, but its brutal legacy continues.




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When I conducted research in Bougainville in 2015, I estimated the deposit of the mine’s waste rock (tailings) downstream from the mine to be at least a kilometre wide at its greatest point. Local residents informed me it was tens of metres deep in places.

I spent several nights in a large two-story house built entirely from a single tree dragged out of the tailings — dragged upright, with a tractor. Every new rainfall brought more tailings downstream and changed the course of the waterways, making life especially challenging for the hundreds of people who eke out a precarious existence panning the tailings for remnants of gold.

The petition has brought the plight of these communities back into the media, but calls for Rio Tinto to clean up its mess have been made for decades. Let’s examine what led to the ongoing crisis.

Triggering a civil war

The Panguna mine was developed in the 1960s, when PNG was still an Australian colony, and operated between 1972 and 1989. It was, at the time, one of the world’s largest copper and gold mines.

It was operated by Bougainville Copper Limited, a subsidiary of what is now Rio Tinto, until 2016 when Rio handed its shares to the governments of Bougainville and PNG.

When a large-scale mining project reaches the end of its commercial life, a comprehensive mine closure and rehabilitation plan is usually put in place.




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But Bougainville Copper simply abandoned the site in the face of a landowner rebellion. This was largely triggered by the mine’s environmental and social impacts, including disputes over the sharing of its economic benefits and the impacts of those benefits on predominantly cashless societies.

Following PNG security forces’ heavy-handed intervention — allegedly under strong political pressure from Bougainville Copper — the rebellion quickly escalated into a full-blown separatist conflict that eventually engulfed all parts of the province.

By the time the hostilities ended in 1997, thousands of Bougainvilleans had lost their lives, including from an air and sea blockade the PNG military had imposed, which prevented essential medical supplies reaching the island.

The mine’s gigantic footprint

The Panguna mine’s footprint was gigantic, stretching across the full breadth of the central part of the island.

The disposal of hundreds of millions of tonnes of tailings into the Kawerong-Jaba river system created enormous problems.

Rivers and streams became filled with silt and significantly widened. Water flows were blocked in many places, creating large areas of swampland and disrupting the livelihoods of hundreds of people in communities downstream of the mine. These communities used the rivers for drinking water and the adjacent lands for subsistence food gardening.

Several villages had to be relocated to make way for the mining operations, with around 200 households resettled between 1969 and 1989.

In the absence of any sort of mine closure or “mothballing” arrangements, the environmental and socio-economic impacts of the Panguna mine have only been compounded.

Since the end of mining activities 30 years ago, tailings have continued to move down the rivers and the waterways have never been treated for suspected chemical contamination.




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Long-suffering communities

The 156 complainants live in communities around and downstream of the mine. Many are from the long-suffering village of Dapera.

In 1975, the people of Dapera were relocated to make way for mining activities. Today, it’s in the immediate vicinity of the abandoned mine pit. As one woman from Dapera told me in 2015:

I have travelled all over Bougainville, and I can say that they [in Dapera] are the poorest of the poor.

They, and others, sent the complaint to the Australian OECD National Contact Point after lodging it with Melbourne’s Human Rights Law Centre.

The complainants say by not ensuring its operations didn’t infringe on the local people’s human rights, Rio Tinto breached OECD guidelines for multinational enterprises.

The Conversation contacted Rio Tinto for comment. A spokesperson said:

We believe the 2016 arrangement provided a platform for the Autonomous Bougainville Government (ABG) and PNG to work together on future options for the resource with all stakeholders.

While it is our belief that from 1990 to 2016 no Rio Tinto personnel had access to the mine site due to on-going security concerns, we are aware of the deterioration of mining infrastructure at the site and surrounding areas, and claims of resulting adverse environmental and social, including human rights, impacts.

We are ready to enter into discussions with the communities that have filed the complaint, along with other relevant parties such as BCL and the governments of ABG and PNG.

A long time coming

This week’s petition comes after a long succession of calls for Rio Tinto to be held to account for the Panguna mine’s legacies and the resulting conflict.

A recent example is when, after Rio Tinto divested from Bougainville Copper in 2016, former Bougainville President John Momis said Rio must take full responsibility for an environmental clean-up.

And in an unsuccessful class action, launched by Bougainvilleans in the United States in 2000, Rio was accused of collaborating with the PNG state to commit human rights abuses during the conflict and was also sued for environmental damages. The case ultimately foundered on jurisdictional grounds.

Two people, one waist-deep in tailings.
Hundreds of millions of tonnes of tailings were deposited in the rivers.
Matthew Allen, Author provided

Taking social responsibility

This highlights the enormous challenges in seeking redress from mining companies for their operations in foreign jurisdictions, and, in this case, for “historical” impacts.

The colonial-era approach to mining when Panguna was developed in the 1960s stands in stark contrast to the corporate social responsibility paradigm supposedly governing the global mining industry today.




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Indeed, Panguna — along with the socially and environmentally disastrous Ok Tedi mine in the western highlands of PNG — are widely credited with forcing the industry to reassess its “social license to operate”.

It’s clear the time has come for Rio to finally take responsibility for cleaning up the mess on Bougainville.The Conversation

Matthew G. Allen, Professor of Development Studies, The University of the South Pacific

This article is republished from The Conversation under a Creative Commons license. Read the original article.

The ocean is swimming in plastic and it’s getting worse – we need connected global policies now



Fotos593 / shutterstock

Steve Fletcher, University of Portsmouth and Keiron Philip Roberts, University of Portsmouth

It seems you cannot go a day without reading about the impact of plastic in our oceans, and for good reason. The equivalent of a garbage truck of plastic waste enters the sea every minute, and this increases every day. If we do nothing, by 2040 the amount of plastic entering the ocean will triple from 13 million tonnes this year, to 29 million tonnes in 2040. That is 50kg of waste plastic entering the ocean for every metre of coastline.

Add to that almost all the plastic that has entered the ocean is still there since it takes centuries to break down. It is either buried or broken down into smaller pieces and potentially passes up the food chain creating further problems.

Despite this, plastic has also been a saviour. During the COVID-19 pandemic plastic used in face masks, testing kits, screens and to protecting food has enabled countries to come out of lockdown during and support social distancing. We still need to use these items until sustainable and “COVID safe” alternatives are available. But we also need to look to the future to reduce our dependence on plastic and its impact on the environment. With plastic in the ocean being a global problem, we need global agreements and policies to reverse the plastic tide.




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Ambitious policies are needed

Environment ministers of the G20 group of the world’s most economically powerful countries and regions met on September 16 to discuss their immediate challenges, with marine plastic pollution a top priority. A key item for discussion was “safeguarding the planet by fostering collective efforts to protect our global commons”. This means working out how we can continue to use the planet’s resources sustainably without harming the environment.

A global analysis of plastics policies over the past two decades found that typical reactions to marine plastic litter were bans or taxes on individual or groups of plastic items within single countries. So far, 43 countries have introduced a ban, tax or levy on plastic bags. Other plastic packaging or single-use plastic products were banned in at least 25 countries, representing a population of almost 2 billion people in 2018.

But plastic waste doesn’t respect land or ocean borders, with mismanaged plastic waste easily migrating from country to country when leaked into the environment. Policies also need to consider the entire plastics life cycle to stand a chance of being effective. For example, the inclusion of easier to recycle plastics in consumer products sounds positive, but their actual recycling rate depends on effective sorting and collection of plastic waste, and appropriate infrastructure being in place.




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Ultimately, a joined up but adaptable set of rules and guidelines are needed so all plastic producers and users can prevent its leakage across all stages of the plastics life cycle.

The G20 has sought to lead action on marine plastic litter through a 2017 Action Plan on Marine Litter which set out areas of concern and possible policy interventions, and through connections to initiatives such as the UN Environment Programme’s Global Partnership on Marine Litter and most recently the Osaka Blue Ocean Vision. The Osaka vision was agreed under the Japanese G20 presidency in 2019 and commits countries to “reduce additional pollution by marine plastic litter to zero by 2050”. Although an agreement led by the G20, it now has the support of 86 countries.

But even with these agreements in place, plastic entering the ocean will still only reduce by 7% by 2040. We need ambitious new agreements as current and emerging policies do not meet the scale of the challenge.

A consensus is forming that the G20 and other global leaders must focus on a systemic change of the plastics economy. This includes focusing on “designing out” plastics, promoting technical and business innovation, immediately scaling up actions known to reduce marine plastic litter, and transitioning to a circular economy in which materials are fully recovered and reused. These actions have the potential to contribute to the G20’s vision of net-zero plastics entering the ocean by 2050, but only if ambitious actions are taken now.The Conversation

Steve Fletcher, Professor of Ocean Policy and Economy, University of Portsmouth and Keiron Philip Roberts, Research Fellow in Clean Carbon Technologies and Resource Management, University of Portsmouth

This article is republished from The Conversation under a Creative Commons license. Read the original article.

How bushfires and rain turned our waterways into ‘cake mix’, and what we can do about it



The Murray River at Gadds Reserve in north east Victoria after Black Summer bushfires.
Paul McInerney, Author provided

Paul McInerney, CSIRO; Anu Kumar, CSIRO; Gavin Rees, CSIRO; Klaus Joehnk, CSIRO, and Tapas Kumar Biswas, CSIRO

As the world watched the Black Summer bushfires in horror, we warned that when it did finally rain, our aquatic ecosystems would be devastated.

Following bushfires, rainfall can wash huge volumes of ash and debris from burnt vegetation and exposed soil into rivers. Fires can also lead to soil “hydrophobia”, where soil refuses to absorb water, which can generate more runoff at higher intensity. Ash and contaminants from the fire, including toxic metals, carbon and fire retardants, can also threaten biodiversity in streams.




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As expected, when heavy rains eventually extinguished many fires, it turned high quality water in our rivers to sludge with the consistency of cake mix.

In the weeks following the first rains, we sampled from these rivers. This is what we saw.

Sampling the upper Murray River

Of particular concern was the upper Murray River on the border between Victoria and NSW, which is critical for water supply. There, the bushfires were particularly intense.

Sludge in Horse Creek near Jingellic following storm activity after the fire.
Paul McInerney/Author Provided

When long-awaited rain eventually came to the upper Murray River catchment, it was in the form of large localised storms. Tonnes of ash, sediment and debris were washed into creeks and the Murray River. Steep terrain within burnt regions of the upper Murray catchment generated a large volume of fast flowing runoff that carried with it sediment and pollutants.

We collected water samples in the upper Murray River in January and February 2020 to assess impacts to riverine plants and animals.

Our water samples were up to 30 times more turbid (cloudy) than normal, with total suspended solids as high as 765 milligrams per litre. Heavy metals such as zinc, arsenic, chromium, nickel, copper and lead were recorded in concentrations well above guideline values for healthy waterways.

Ash and sediment blanketing cobbles in the Murray River.
Paul McInerney/Author Provided

We took the water collected from the Murray River to the laboratory, where we conducted a number of toxicological experiments on duckweed (a floating water plant), water fleas (small aquatic invertebrates) and juvenile freshwater snails.

What we found

During a seven-day exposure to the bushfire affected river water, the growth rate of duckweed was reduced by 30-60%.

The water fleas ingested large amounts of suspended sediments when they were exposed to the affected water for 48 hours. Following the exposure, water flea reproduction was significantly impaired.

And freshwater snail egg sacs were smothered. The ash resulted in complete deaths of snail larvae after 14 days.




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Before and after: see how bushfire and rain turned the Macquarie perch’s home to sludge


These sad impacts to growth, reproduction and death rates were primarily a result of the combined effects of the ash and contaminants, according to our preliminary investigations.

But they can have longer-term knock-on effects to larger animals like birds and fish that rely on biota like snail eggs, water fleas and duckweed for food.

What happened to the fish?

Immediately following the first pulse of sediment, dead fish (mostly introduced European carp and native Murray Cod) were observed on the bank of River Murray at Burrowye Reserve, Victoria. But what, exactly, was their cause of death?

A dead Murray Cod found on the banks of the Murray River following storms after the bushfires.
Paul McInerney/Author Provided

Our first assumption was that they died from a lack of oxygen in the water. This is because ash and nutrients combined with high summer water temperatures can trigger increased activity of microbes, such as bacteria.

This, in turn can deplete the dissolved oxygen concentration in the water (also known as hypoxia) as the microbes consume oxygen. And wide-spread hypoxia can lead to large scale fish kills.




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But to our surprise, although dissolved oxygen in the Murray River was lower than usual, we did not record it at levels low enough for hypoxia. Instead, we saw the dead fish had large quantities of sediment trapped in their gills. The fish deaths were also quite localised.

In this case, we think fish death was simply caused by the extremely high sediment and ash load in the river that physically clogged their gills, not a lack of dissolved oxygen in the water.

These findings are not unusual, and following the 2003 bushfires in Victoria fish kills were attributed to a combination of low dissolved oxygen and high turbidity.

So how can we prepare for future bushfires?

Preventing sediment being washed into rivers following fires is difficult. Installing sediment barriers and other erosion control measures can protect specific areas. However, at the catchment scale, a more holistic approach is required.




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One way is to increase efforts to re-vegetate stream banks (called riparian zones) to help buffer the runoff. A step further is to consider re-vegetating these zones with native plants that don’t burn easily, such as Blackwood (Acacia melanoxylin).

Streams known to host rare or endangered aquatic species should form the focus of any fire preparation activities. Some species exist only in highly localised areas, such as the endangered native barred galaxias (Galaxias fuscus) in central Victoria. This means an extreme fire event there can lead to the extinction of the whole species.

Ash and dead fish on the banks of the Murray River near Jingellic following Black Summer fires.
Paul McInerney/Author Provided

That’s why reintroducing endangered species to their former ranges in multiple catchments to broaden their distribution is important.

Increasing the connectivity within our streams would also allow animals like fish to evade poor water quality — dams and weirs can prevent this. The removal of such barriers, or installing “fish-ways” may be important to protecting fish populations from bushfire impacts.

However, dams can also be used to benefit animal and plant life (biota). When sediment is washed into large rivers, as we saw in the Murray River after the Black Summer fires, the release of good quality water from dams can be used to dilute poor quality water washed in from fire affected tributaries.




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Citizen scientists can help, too. It can be difficult for researchers to monitor aquatic ecosystems during and immediately following bushfires and unmanned monitoring stations are often damaged or destroyed.

CSIRO is working closely with state authorities and the public to improve citizen science apps such as EyeOnWater to collect water quality data. With more eyes in more areas, these data can improve our understanding of aquatic ecosystem responses to fire and to inform strategic planning for future fires.

These are some simple first steps that can be taken now.

Recent investment in bushfire research has largely centred on how the previous fires have influenced species’ distribution and health. But if we want to avoid wildlife catastrophes, we must also look forward to the mitigation of future bushfire impacts.The Conversation

Paul McInerney, Research scientist, CSIRO; Anu Kumar, Principal Research Scientist, CSIRO; Gavin Rees, Principal Research Scientist, CSIRO; Klaus Joehnk, Principal research scientist, CSIRO, and Tapas Kumar Biswas, Senior scientist, CSIRO

This article is republished from The Conversation under a Creative Commons license. Read the original article.

After a storm, microplastics in Sydney’s Cooks River increased 40 fold



A litter trap in Cook’s River.
James HItchcock, Author provided

James Hitchcock, University of Canberra

Each year the ocean is inundated with 4.8 to 12.7 million tonnes of plastic washed in from land. A big proportion of this plastic is between 0.001 to 5 millimetres, and called “microplastic”.

But what happens during a storm, when lashings of rain funnel even more water from urban land into waterways? To date, no one has studied just how important storm events may be in polluting waterways with microplastics.




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So to find out, I studied my local waterway in Sydney, the Cooks River estuary. I headed out daily to measure how many microplastics were in the water, before, during, and after a major storm event in October, 2018.

The results, published on Wednesday, were startling. Microplastic particles in the river had increased more than 40 fold from the storm.

Particles of plastic found in rivers. They may be tiny, but they’re devastating to wildlife in waterways.
Author provided

To inner west Sydneysiders, the Cooks River is known to be particularly polluted. But it’s largely similar to many urban catchments around the world.

If the relationship between storm events and microplastic I found in the Cooks River holds for other urban rivers, then the concentrations of microplastics we’re exposing aquatic animals to is far higher than previously thought.

14 million plastic particles

They may be tiny, but microplastics are a major concern for aquatic life and food webs. Animals such as small fish and zooplankton directly consume the particles, and ingesting microplastics has the potential to slow growth, interfere with reproduction, and cause death.

Determining exactly how much microplastic enters rivers during storms required the rather unglamorous task of standing in the rain to collect water samples, while watching streams of unwanted debris float by (highlights included a fire extinguisher, a two-piece suit, and a litany of tennis balls).

Back in the laboratory, a multi-stage process is used to separate microplastics. This includes floating, filtering, and using strong chemical solutions to dissolve non-plastic items, before identification and counting with specialised microscopes.

Litter caught in a trap in Cooks River. These traps aren’t effective at catching microplastic.
Author provided

In the days before the October 2018 storm, there were 0.4 particles of microplastic per litre of water in the Cooks River. That jumped to 17.4 microplastics per litre after the storm.

Overall, that number averages to a total of 13.8 million microplastic particles floating around in the Cooks River estuary in the days after the storm.




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In other urban waterways around the world scientists have found similarly high numbers of microplastic.

For example in China’s Pearl River, microplastic averages 19.9 particles per litre. In the Mississippi River in the US, microplastic ranges from 28 to 60 particles per litre.

Where do microplastics come from?

We know runoff during storms is one of the main ways pollutants such as sediments and heavy metals end up in waterways. But not much is known about how microplastic gets there.

However think about your street. Wherever you see litter, there are also probably microplastics you cannot see that will eventually work their way into waterways when it rains.




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Many other sources of microplastics are less obvious. Car tyres, for example, which typically contain more plastic than rubber, are a major source of microplastics in our waterways. When your tyres lose tread over time, microscopic tyre fragments are left on roads.

Did you know your car tyres can be a major source of microplastic pollution?
Shutterstock

Microplastics may even build up on roads and rooftops from atmospheric deposition. Everyday, lightweight microplastics such as microfibres from synthetic clothing are carried in the wind, settling and accumulating before they’re washed into rivers and streams.

What’s more, during storms wastewater systems may overflow, contaminating waterways. Along with sewage, this can include high concentrations of synthetic microfibers from household washing machines.

And in regional areas, microplastics may be washing in from agricultural soils. Sewage sludge is often applied to soils as it is rich in nutrients, but the same sludge is also rich in microplastics.

What can be done?

There are many ways to mitigate the negative effects of stormwater on waterways.

Screens, traps, and booms can be fitted to outlets and rivers and catch large pieces of litter such as bottles and packaging. But how useful these approaches are for microplastics is unknown.

Raingardens and retention ponds are used to catch and slow stormwater down, allowing pollutants to drop to bottom rather than being transported into rivers. Artificial wetlands work in similar ways, diverting stormwater to allow natural processes to remove toxins from the water.

Almost 14 million plastic particles were floating in Cooks River after a storm two years ago.
Shutterstock

But while mitigating the effects of stormwater carrying microplastics is important, the only way we’ll truly stop this pollution is to reduce our reliance on plastic. We must develop policies to reduce and regulate how much plastic material is produced and sold.

Plastic is ubiquitous, and its production around the world hasn’t slowed, reaching 359 million tonnes each year. Many countries now have or plan to introduce laws regulating the sale or production of some items such as plastic bags, single-use plastics and microbeads in cleaning products.




Read more:
We have no idea how much microplastic is in Australia’s soil (but it could be a lot)


In Australia, most state governments have committed to banning plastic bags, but there are still no laws banning the use of microplastics in cleaning or cosmetic products, or single-use plastics.

We’ve made a good start, but we’ll need deeper changes to what we produce and consume to stem the tide of microplastics in our waterways.The Conversation

James Hitchcock, Post-Doctoral Research Fellow, University of Canberra

This article is republished from The Conversation under a Creative Commons license. Read the original article.

NSW has approved Snowy 2.0. Here are six reasons why that’s a bad move



Lucas Coch/AAP

Bruce Mountain, Victoria University and Mark Lintermans, University of Canberra

The controversial Snowy 2.0 project has mounted a major hurdle after the New South Wales government today announced approval for its main works.

The pumped hydro venture in southern NSW will pump water uphill into dams and release it when electricity demand is high. The federal government says it will act as a giant battery, backing up intermittent energy from by wind and solar.

We and others have criticised the project on several grounds. Here are six reasons we think Snowy 2.0 should be shelved.

1. It’s really expensive

The federal government announced the Snowy 2.0 project without a market assessment, cost-benefit analysis or indeed even a feasibility study.

When former Prime Minister Malcolm Turnbull unveiled the Snowy expansion in March 2017, he said it would cost A$2 billion and be commissioned by 2021. This was revised upwards several times and in April last year, Snowy Hydro awarded a A$5.1 billion contract for partial construction.

Snowy Hydro has not costed the transmission upgrades on which the project depends. TransGrid, owner of the grid in NSW, has identified options including extensions to Sydney with indicative costs up to A$1.9 billion. Massive extensions south, to Melbourne, will also be required but this has not been costed.

The Tumut 3 scheme, with which Snowy 2.0 will share a dam.
Snowy Hydro Ltd

2. It will increase greenhouse gas emissions

Both Snowy Hydro Ltd and its owner, the federal government, say the project will help expand renewable electricity generation. But it won’t work that way. For at least the next couple of decades, analysis suggests Snowy 2.0 will store coal-fired electricity, not renewable electricity.

Snowy Hydro says it will pump the water when a lot of wind and solar energy is being produced (and therefore when wholesale electricity prices are low).




Read more:
Snowy 2.0 is a wolf in sheep’s clothing – it will push carbon emissions up, not down


But wind and solar farms produce electricity whenever the resource is available. This will happen irrespective of whether Snowy 2.0 is producing or consuming energy.

When Snowy 2.0 pumps water uphill to its upper reservoir, it adds to demand on the electricity system. For the next couple of decades at least, coal-fired electricity generators – the next cheapest form of electricity after renewables – will provide Snowy 2.0’s power. Snowy Hydro has denied these claims.

Khancoban Dam, part of the soon-to-be expanded Snowy Hydro scheme.
Snowy Hydro Ltd

3. It will deliver a fraction of the energy benefits promised

Snowy 2.0 is supposed to store renewable energy for when it is needed. Snowy Hydro says the project could generate electricity at its full 2,000 megawatt capacity for 175 hours – or about a week.

But the maximum additional pumped hydro capacity Snowy 2.0 can create, in theory, is less than half this. The reasons are technical, and you can read more here.

It comes down to a) the amount of time and electricity required to replenish the dam at the top of the system, and b) the fact that for Snowy 2.0 to operate at full capacity, dams used by the existing hydro project will have to be emptied. This will result in “lost” water and by extension, lost electricity production.



The Conversation, CC BY-ND

4. Native fish may be pushed to extinction

Snowy 2.0 involves building a giant tunnel to connect two water storages – the Tantangara and Talbingo reservoirs. By extension, the project will also connect the rivers and creeks connected to these reservoirs.

A small, critically endangered native fish, the stocky galaxias, lives in a creek upstream of Tantangara. This is the last known population of the species.

The stocky galaxias.
Hugh Allan

An invasive native fish, the climbing galaxias, lives in the Talbingo reservoir. Water pumped from Talbingo will likely transfer this fish to Tantangara.

From here, the climbing galaxias’ capacity to climb wet vertical surfaces would enable it to reach upstream creeks and compete for food with, and prey on, stocky galaxias – probably pushing it into extinction.

Snowy 2.0 is also likely to spread two other problematic species – redfin perch and eastern gambusia – through the headwaters of the Murrumbidgee, Snowy and Murray rivers.




Read more:
Snowy 2.0 threatens to pollute our rivers and wipe out native fish


5. It’s a pollution risk

Snowy Hydro says its environmental impact statement addresses fish transfer impacts, and potentially serious water quality issues.

Four million tonnes of rock excavated to build Snowy 2.0 would be dumped into the two reservoirs. The rock will contain potential acid-forming minerals and other harmful substances, which threaten to pollute water storages and rivers downstream.

When the first stage of the Snowy Hydro project was built, comparable rocks were dumped in the Tooma River catchment. Research in 2006 suggested the dump was associated with eradication of almost all fish from the Tooma River downstream after rainfall.

Snowy 2.0 threatens to pollute pristine Snowy Mountains rivers.
Schopier/Wikimedia

6. Other options were not explored

Many competing alternatives can provide storage far more flexibly for a fraction of Snowy 2.0’s price tag. These alternatives would also have far fewer environmental impacts or development risks, in most cases none of the transmission costs and all could be built much more quickly.

Expert analysis in 2017 identified 22,000 potential pumped hydro energy storage sites across Australia.

Other alternatives include chemical batteries, encouraging demand to follow supply, gas or diesel generators, and re-orienting more solar capacity to capture the sun from the east or west, not just mainly the north.

Where to now?

The federal government, which owns Snowy Hydro, is yet to approve the main works.

Given the many objections to the project and how much has changed since it was proposed, we strongly believe it should be put on hold, and scrutinised by independent experts. There’s too much at stake to get this wrong.




Read more:
Five gifs that explain how pumped hydro actually works


The Conversation


Bruce Mountain, Director, Victoria Energy Policy Centre, Victoria University and Mark Lintermans, Associate professor, University of Canberra

This article is republished from The Conversation under a Creative Commons license. Read the original article.