Rum Jungle used to be a household name. It was Australia’s first large-scale uranium mine and supplied the US and British nuclear weapons programs during the Cold War.
Today, the mine is better known for extensively polluting the Finniss River after it closed in 1971. Despite a major rehabilitation project by the Commonwealth in the 1980s, the damage to the local environment is ongoing.
I first visited Rum Jungle in 2004, and it was a colourful mess, to say the least. Over later years, I saw it worsen. Instead of a river bed, there were salt crusts containing heavy metals and radioactive material. Pools of water were rich reds and aqua greens — hallmarks of water pollution. Healthy aquatic species were nowhere to be found, like an ecological desert.
The government’s second rehabilitation attempt is significant, as it recognises mine rehabilitation isn’t always successful, even if it appears so at first.
Rum Jungle serves as a warning: rehabilitation shouldn’t be an afterthought, but carefully planned, invested in and monitored for many, many years. Otherwise, as we’ve seen, it’ll be left up to future taxpayers to fix.
The mine was owned by the federal government, but was operated under contract by a former subsidiary of Rio Tinto. Back then, there were no meaningful environmental regulations in place for mining, especially for a military project.
The waste rock and tailings (processed ore) at Rum Jungle contains significant amounts of iron sulfide, called “pyrite”. When mining exposes the pyrite to water and oxygen, a chemical reaction occurs generating so-called “acidic mine drainage”. This drainage is rich in acid, salts, heavy metals and radioactive material (radionuclides), such as copper, zinc and uranium.
Acid drainage seeping from waste rock, plus acidic liquid waste from the process plant, caused fish and macroinvertebrates (bugs, worms, crustaceans) to die out, and riverbank vegetation to decline. By the time the mine closed in 1971, the region was a well-known ecological wasteland.
When mines close, the modern approach is to rehabilitate them to an acceptable condition, with the aim of minimal ongoing environmental damage. But after working in environmental engineering across Australia for 26 years, I’ve seen few mines completely rehabilitated — let alone successfully.
This is why Rum Jungle is so important: it was one of the very few mines once thought to have been rehabilitated successfully.
So what went wrong?
From 1983 to 1986, the government spent some A$18.6 million (about $55.5 million in 2020 value) to reduce acid drainage and restore the Finniss River ecology. Specially engineered soil covers were placed over the waste rock to reduce water and oxygen getting into the pyrite.
The engineering project was widely promoted as successful through conferences and academic studies, with water quality monitoring showing that the metals polluting the Finniss had substantially subsided. But this lasted only for a decade.
First, the design was insufficient to reduce infiltration of water during the wet season (thicker covers should have been used). Second, the covers weren’t built to design in parts (they were thinner and with the wrong type of soils).
The first reason is understandable, we’d never done this before. But the second is not acceptable, as the thinner covers and wrong soils made it easier for water and oxygen to get into the waste rock and generate more polluting acid mine drainage.
We got it wrong with Rum Jungle, which generated less than 20 million tonnes of mine waste. Modern mines, such as Mount Whaleback in the Pilbara, now involve billions of tonnes — and we have dozens of them. Getting even a small part of modern mine rehabilitation wrong could, at worst, mean billions of tonnes of mine waste polluting for centuries.
Given its acid drainage risks, the mine’s rehabilitation involved placing reactive waste into the open pit, rather than using soil covers. “Backfilling” such wastes into pits makes good sense, as the pyrite is deeper and not exposed to oxygen, substantially reducing acid drainage risks.
Backfilling isn’t commonly used because it’s widely perceived in the industry as expensive. Clearly, we need to better assess rehabilitation costs and benefits to justify long-term options, steering clear of short-term, lowest-cost approaches.
The Woodcutters experience shows such thinking can be done to improve the chances for successfully restoring the environment.
We all know it’s wrong to toss your rubbish into the ocean or another natural place. But it might surprise you to learn some plastic waste ends up in the environment, even when we thought it was being recycled.
Our study, published today, investigated how the global plastic waste trade contributes to marine pollution.
We found plastic waste most commonly leaks into the environment at the country to which it’s shipped. Plastics which are of low value to recyclers, such as lids and polystyrene foam containers, are most likely to end up polluting the environment.
The export of unsorted plastic waste from Australia is being phased out – and this will help address the problem. But there’s a long way to go before our plastic is recycled in a way that does not harm nature.
Know your plastics
Plastic waste collected for recycling is often sold for reprocessing in Asia. There, the plastics are sorted, washed, chopped, melted and turned into flakes or pellets. These can be sold to manufacturers to create new products.
The global recycled plastics market is dominated by two major plastic types:
polyethylene terephthalate (PET), which in 2017 comprised 55% of the recyclable plastics market. It’s used in beverage bottles and takeaway food containers and features a “1” on the packaging
high-density polyethylene (HDPE), which comprises about 33% of the recyclable plastics market. HDPE is used to create pipes and packaging such as milk and shampoo bottles, and is identified by a “2”.
The next two most commonly traded types of plastics, each with 4% of the market, are:
polypropylene or “5”, used in containers for yoghurt and spreads
low-density polyethylene known as “4”, used in clear plastic films on packaging.
The remaining plastic types comprise polyvinyl chloride (3), polystyrene (6), other mixed plastics (7), unmarked plastics and “composites”. Composite plastic packaging is made from several materials not easily separated, such as long-life milk containers with layers of foil, plastic and paper.
This final group of plastics is not generally sought after as a raw material in manufacturing, so has little value to recyclers.
China banned the import of plastic waste in January 2018 to prevent the receipt of low-value plastics and to stimulate the domestic recycling industry.
Following the bans, the global plastic waste trade shifted towards Southeast Asian nations such as Vietnam, Thailand, Malaysia, and Indonesia. The largest exporters of waste plastics in 2019 were Europe, Japan and the US. Australia exported plastics primarily to Malaysia and Indonesia.
Australia’s waste export ban recently became law. From July this year, only plastics sorted into single resin types can be exported; mixed plastic bales cannot. From July next year, plastics must be sorted, cleaned and turned into flakes or pellets to be exported.
This may help address the problem of recyclables becoming marine pollution. But it will require a significant expansion of Australian plastic reprocessing capacity.
What we found
Our study was funded by the federal Department of Agriculture, Water and the Environment. It involved interviews with trade experts, consultants, academics, NGOs and recyclers (in Australia, India, Indonesia, Japan, Malaysia, Vietnam and Thailand) and an extensive review of existing research.
We found when it comes to the international plastic trade, plastics most often leak into the environment at the destination country, rather than at the country of origin or in transit. Low-value or “residual” plastics – those left over after more valuable plastic is recovered for recycling – are most likely to end up as pollution. So how does this happen?
In Southeast Asia, often only registered recyclers are allowed to import plastic waste. But due to high volumes, registered recyclers typically on-sell plastic bales to informal processors.
Interviewees said when plastic types were considered low value, informal processors frequently dumped them at uncontrolled landfills or into waterways. Sometimes the waste is burned.
Plastics stockpiled outdoors can be blown into the environment, including the ocean. Burning the plastic releases toxic smoke, causing harm to human health and the environment.
Interviewees also said when informal processing facilities wash plastics, small pieces end up in wastewater, which is discharged directly into waterways, and ultimately, the ocean.
However, interviewees from Southeast Asia said their own domestic waste management was a greater source of ocean pollution.
A market failure
The price of many recycled plastics has crashed in recent years due to oversupply, import restrictions and falling oil prices, (amplified by the COVID-19 pandemic). However clean bales of PET and HDPE are still in demand.
In Australia, material recovery facilities currently sort PET and HDPE into separate bales. But small contaminants of other materials (such as caps and plastic labels) remain, making it harder to recycle into high quality new products.
Before the price of many recycled plastics dropped, Australia baled and traded all other resin types together as “mixed plastics”. But the price for mixed plastics has fallen to zero and they’re now largely stockpiled or landfilled in Australia.
Several Australian facilities are, however, investing in technology to sort polypropylene so it can be recovered for recycling.
Doing plastics differently
Exporting countries can help reduce the flow of plastics to the ocean by better managing trade practices. This might include:
improving collection and sorting in export countries
checking destination processing and monitoring
checking plastic shipments at export and import
improving accountability for shipments.
But this won’t be enough. The complexities involved in the global recycling trade mean we must rethink packaging design. That means using fewer low-value plastic and composites, or better yet, replacing single-use plastic packaging with reusable options.
The authors would like to acknowledge research contributions from Asia Pacific Waste Consultants (APWC) – Dr Amardeep Wander, Jack Whelan and Anne Prince, as well as Phil Manners at CIE.
Australia’s wetlands are home to a huge range of stunning flora and fauna, with large snakes often at the top of the food chain.
Many wetlands are located near urban areas. This makes them particularly susceptible to contamination as stormwater, urban drainage and groundwater can wash metals — such as arsenic, cadmium, lead and mercury — into the delicate ecosystem.
We know many metals can travel up the food chain when they’re present in the environment. So to assess contamination levels, we caught highly venomous tiger snakes across wetlands in Perth, and repurposed laser technology to measure the metals they accumulated.
In our new paper, we show metal contamination in wild wetland tiger snakes is chronic, and highest in human-disturbed wetlands. This suggests all other plants and animals in these wetlands are likely contaminated as well.
34 times more arsenic in wild wetland snakes than captive snakes
Urban growth and landscape modification often introduces metals into the surrounding environment, such as mining, landfill and waste dumps, vehicles and roadworks, and agriculture.
When they reach wetlands, sediments collect and store these metals for hundreds of years. And if a wetland’s natural water levels are lowered, from agricultural draining for example, sediments can become exposed and erode. This releases the metals they’ve been storing into the ecosystem.
This is what we suspect happened in Yanchep National Park’s wetland, which was supposed to be our “clean” comparison site to more urban wetlands. But in a 2020 study looking at sediment contamination, we found this wetland had higher levels of selenium, mercury, chromium and cadmium compared to urban wetlands we tested.
And at Herdsman Lake, our most urban wetland five minutes from the Perth city centre, we found concentrations of arsenic, lead, copper and zinc in sediment up to four times higher than government guidelines.
In our new study on tiger snake scales, we compared the metal concentrations in wild wetland tiger snakes to the concentrations that naturally occurs in captive-bred tiger snakes, and to the sediment in the previous study.
We found arsenic was 20-34 times higher in wild snakes from Herdsman Lake and Yanchep National Park’s wetland. And snakes from Herdsman Lake had, on average, eight times the amount of uranium in their scales compared to their captive-bred counterparts.
Tiger snakes usually prey on frogs, so our results suggest frogs at these lakes are equally as contaminated.
We know for many organisms, exposure to a high concentration of metals is fatally toxic. And when contamination is chronic, it can be “neurotoxic”. This can, for example, change an organism’s behaviour so they eat less, or don’t want to breed. It can also interfere with their normal cellular function, compromising immune systems, DNA repair or reproductive processes, to name a few.
Snakes in general appear relatively resistant to the toxic effects of metal contamination, but we’re currently investigating what these levels of contamination are doing to tiger snakes’ health and well-being.
Our method keeps snakes alive
Snakes can be a great indicator of environmental contamination because they generally live for a long time (over 10 years) and don’t travel too far from home. So by measuring metals in older snakes, we can assess the contamination history of the area they were collected from.
Typically, scientists use liver tissue to measure biological contamination since it acts like a filter and retains a substantial amount of the contaminants an animal is exposed to.
But a big problem with testing the liver is the animal usually has to be sacrificed. This is often not possible when studying threatened species, monitoring populations or working with top predators.
In more recent years, studies have taken to measuring metals in external “keratin” tissues instead, which include bird feathers, mammal hair and nails, and reptile scales. As it grows, keratin can accumulate metals from inside the body, and scientists can measure this without needing to kill the animal.
Our research used “laser ablation” analysis, which involves firing a focused laser beam at a solid sample to create a small crater or trench. Material is excavated from the crater and sent to a mass spectrometer (analytical machine) where all the elements are measured.
This technology was originally designed for geologists to analyse rocks, but we’re among the first researchers applying it to snake scales.
Laser ablation atomises the keratin of snake scales, and allowed us to accurately measure 19 contaminants from each tiger snake caught over three years around different wetlands.
We need to minimise pollution
Our research has confirmed snake scales are a good indicator of environmental contamination, but this is only the first step.
Further research could allow us to better use laser ablation as a cost-effective technology to measure a larger suite of metals in different parts of the ecosystem, such as in different animals at varying levels in the food chain.
This could map how metals move throughout the ecosystem and help determine whether the health of snakes (and other top predators) is actually at risk by these metal levels, or if they just passively record the metal concentrations in their environment.
It’s difficult to prevent contaminants from washing into urban wetlands, but there are a number of things that can help minimise pollution.
This includes industries developing strict spill management requirements, and local and state governments deploying storm-water filters to catch urban waste. Likewise, thick vegetation buffer zones around the wetlands can filter incoming water.
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.
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.
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.
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.
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 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 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.
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.
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.
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.
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.
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.
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.
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 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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
So what’s driving overfishing?
There are many reasons why overfishing occurs and why it is goes unchecked. The evidence points to:
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.
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.
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.
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.
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.
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.
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.
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 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.
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.
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.
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 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 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.
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.
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