A remote South Pacific island has the highest density of plastic debris reported anywhere on the planet, our new study has found.
Our study, published in the journal Proceedings of the National Academy of Sciences, estimated that more than 17 tonnes of plastic debris has washed up on Henderson Island, with more than 3,570 new pieces of litter arriving every day on one beach alone.
It is wet season in Bali, Indonesia, a popular tourist destination for Australian, Russian, German, Chinese and Japanese visitors.
As the rain pounds down on banana leaves and rice fields, the rivers fill up and irrigation systems overflow. With it, the water masses bring trash in bulk: anything from food wrappers and plastic bags to bottles and other domestic waste.
To tackle the issue of marine pollution, several organisations got together in Nusa Dua – a popular tourist destination – and other locations across Bali to stage the largest beach clean-up the island has seen.
While the beach clean-up was a hugely successful awareness campaign and a great promotion which highlights the efforts done around the island, it is only a drop in the ocean of global marine pollution.
Plastic pollution in Indonesia
In recent years, Bali has seen growing environmental problems such as pollution and freshwater scarcity. Popular tourist destination Kuta beach is regularly covered in waste. Most of this is plastic that washes ashore during the rainy season.
The island’s garbage dumps are reportedly overflowing,. This makes solid waste management a pressing issue. Substantial groundwater resources are predicted to run dry by 2020, threatening freshwater resources.
On top of that, Indonesia is the world’s second-biggest marine polluter after China, discarding 3.22 million metric tons of waste annually. This accounts for 10% of the world’s marine pollution.
The summit was attended by state leaders such as Indonesian Vice President Jusuf Kalla, representatives of major global economic organisations such as Citigroup managing director Michael Eckhart, and celebrity and entrepreneur Adrian Grenier.
Speakers and panels discussed a number of topics, including the “blue economy” and how companies and governments can participate in this marine-based sustainable industry.
But not all voices are heard in this global debate. Many Bali-based environmental organisations engaged in education programs were not represented at the summit. Those economically most vulnerable to pollution – such as beach vendors, fishermen and others employed in the marine tourism trade – appear to be left out of the conversation.
Marine pollution and tourism
The Indonesian government plans to boost tourism and increase national visitors from 9.7 million in 2015 to 20 million by 2020. Such increases in visitor numbers and population will raise consumption and waste production, further pressuring the island’s infrastructure and ecosystems.
Marine communities may also suffer negative socio-economic consequences, as fishermen can lose their livelihood and tourism operators lose their customers.
While some tourism operators understand that clean beaches are key in attracting international tourists, the expected growth is likely to further stress Bali’s environment.
What is being done?
Efforts by activists, community groups and NGOs to clean beaches play a key role in protecting Bali’s environment. But they are only a temporary fix and don’t tackle the causes of this global problem.
Such groups are leading the fight against over-development and pollution through protests, clean-up events and educational programs.
Campaigners from Bali-based environmental youth group “Bye Bye Plastic Bags” advocate for an island-wide ban on plastic bags. They also spoke at the Ocean Summit.
And while they convinced Bali’s governor to commit to make the island plastic-bag-free by 2018, continued development of legislation, regulation and industry guidelines is needed to save Indonesia’s waterways from drowning in waste.
While carbon pollution gets all the headlines for its role in climate change, nitrogen pollution is arguably a more challenging problem. Somehow we need to grow more food to feed an expanding population while minimising the problems associated with nitrogen fertiliser use.
In Europe alone, the environmental and human health costs of nitrogen pollution are estimated to be €70-320 billion per year.
Nitrogenous gases also play an important role in global climate change. Nitrous oxide is a particularly potent greenhouse gas as it is over 300 times more effective at trapping heat in the atmosphere than carbon dioxide.
Nitrogen from fertiliser, effluent from livestock and human sewage boost the growth of algae and cause water pollution. The estimated A$8.2 billion damage bill to the Great Barrier Reef is a reminder that our choices on land have big impacts on land, water and the air downstream.
Lost nitrogen harms farmers too, as it represents reduced potential crop growth or wasted fertiliser. This impact is most acute for smallholder farmers in developing countries, for whom nitrogen fertiliser is often the biggest cost of farming. The reduced production from the lost nitrogen can represent as much as 25% of the household income.
The solution to the nitrogen challenge will need to come from a combination of technological innovation, policy and consumer action.
The essential ingredient
Nitrogen is an essential building block for amino acids, proteins and DNA. Plant growth depends on it; animals and people get it from eating plants or other animals.
Nitrogen gas (N₂) makes up 78% of the air, but it cannot be used by plants. Fertilisers are usually made from ammonia, a form of nitrogen that the plants prefer.
In fact, nitrogen from fertiliser now accounts for more than half the protein in the human diet. Yet some 50% of applied nitrogen is lost to the environment in water run-off from fields, animal waste and gas emissions from soil microbe metabolism.
These losses have been increasing over the decades as nitrogen fertiliser use increases. Reactive nitrogen causes wide-ranging damage, and will cause more damage if nitrogen losses are not reined in.
Faced with a growing population and changing climate, we need more than ever to optimise the use of nitrogen and minimise the losses.
From farm to fork
One way to understand our nitrogen use is to look at our nitrogen footprint – the amount of nitrogen pollution released to the environment from food, housing, transportation and goods and services.
Research by University of Melbourne PhD candidate Emma Liang shows Australia has a large nitrogen footprint. At 47kg of nitrogen per person each year, Australia is far ahead of the US, which came in with 28kg of nitrogen per person.
Animal products carry high nitrogen costs compared to vegetable products. Both products start with the same cost in nitrogen as a result of growing a crop, but significant further losses occur as the animal consumes food throughout its life cycle.
The N-Footprint project aims to help individuals and institutions calculate their nitrogen footprints. It shows how we can each have an impact on nitrogen pollution through our everyday choices.
We can choose to eat lower nitrogen footprint protein diets, such as vegetables, chicken and seafood instead of beef and lamb. We can choose to reduce food waste by buying smaller quantities (and more frequently if necessary) and composting food waste. The good news is, if we reduce our nitrogen footprint, we also reduce our carbon footprint.
Back to the farm
In the meantime, efforts to use nitrogen more efficiently on farms must continue. We are getting better at understanding nitrogen losses from soil through micrometerological techniques.
From sitting in the sun with plastic bucket chambers, glass vials and syringes, scientists now use tall towers and lasers to detect small changes in gas concentrations over large areas and send the results directly to our computers.
We now know nitrification (when ammonia is converted to nitrate) is an important contributor to nitrogen losses and therefore climate change and damage to ecosystems. It is a process researchers – and farmers – are targeting to reduce nitrogen losses.
Nitrification inhibitors are now used commercially to keep nitrogen in the ammonium form, which plants prefer, and to prevent the accumulation of nitrate, which is more easily lost to the environment.
As this technology advances, we are starting to answer the question of how these inhibitors affect the microbial communities that maintain the health of our soil and form the foundation of ecosystems.
For example, our research shows that 3,4-dimethylpyrazole phosphate (better known as DMPP) inhibits nitrification without affecting soil microbial community diversity.
There have also been exciting observations that the root systems of some tropical grasses inhibit nitrification. This opens up a management option to slow nitrification rates in the environment using genetic approaches.
Solving the challenge of nitrogen use will require research into more efficient ways for primary producers to use nitrogen, but it will also need government leadership and consumer choices to waste less or eat more plant protein. These tools will make the case for change clearer, and the task of feeding the world greener.
Ask most people about pollution, and they will think of rubbish, plastic, oil, smog, and chemicals. After some thought, most folks might also suggest noise pollution.
We’re all familiar with noise around us, and we know it can become a problem – especially if you live near an airport, train station, highway, construction site, or DIY-enthusiast neighbour.
But most people don’t think that noise is a problem under water. If you’ve read Jules Verne’s Twenty Thousand Leagues Under the Sea you might imagine that, maelstroms excepted, life is pretty quiet in the ocean. Far from it.
When we put a hydrophone (essentially a waterproof microphone) into the water, no matter where in the world’s oceans, it’s never quiet. We hear wind blowing overhead and rain dropping onto the ocean surface – even from hundreds of metres deep. In Australian waters we can also detect the far-off rumbles of earthquakes and the creaking of Antarctic ice thousands of kilometres away.
Wet and noisy
Water is much denser than air, so its molecules are packed tighter together. This means that sound (which relies on molecules vibrating and pushing against one another) propagates much further and faster under water than in air.
This also applies to human-produced sound. Under water we can hear boats and ships and even aeroplanes. Large vessels in deep water can be detected tens of kilometres away. We can be far offshore doing fieldwork, the only people around, with nothing in sight but water in any direction. Yet when we switch the engines off and put a hydrophone into the water, we hear ship noise. Sometimes, whole minutes later, the vessel we heard might appear on the horizon.
Seafarers have known about another source of sound for thousands of years: marine life. Many animals produce sound, from the tiniest shrimp to the biggest whales. Many fish even communicate acoustically under water – during the mating season, the boys start calling. Whales do it, too.
Light doesn’t reach far under water. Near the surface, in clear water, you might be able to peer a few metres, but in the inky depths you can’t see at all. So many marine animals have evolved to “see with sound”, using acoustics for navigation, for detecting predators and prey, and for communicating with other members of their species.
The thing is that man-made sound can interfere with these behaviours.
The effects of noise on marine animals are similar to those on us. If you’ve ever been left with ringing ears after a rock concert, you’ll know that loud noise can temporarily affect your hearing or even damage it permanently.
Noise interferes with communication, often masking it. Can you talk above the background noise in a busy pub? Long-term exposure to noise can cause stress and health issues — in humans and animals alike.
Excessive noise can change marine creatures’ habits, too. Like a person who decides to move house rather than live next door to a new airport, animals might choose to desert their habitat if things get too noisy. The question is whether they can find an equally acceptable habitat elsewhere.
There is a lot more research still to be done in this field. Can we predict what noises and vibrations might be released into the marine environment by new machinery or ships? How does sound propagate through different ocean environments? What are the long-term effects on marine animal populations?
One positive is that even though noise pollution travels very fast and very far through the ocean, the moment you switch off the source, the noise is gone. This is very much unlike plastic or chemical pollution, and gives us hope that noise pollution can be successfully managed.
We all need energy, some of which comes from oil and gas; most of our consumer goods are shipped across the seas on container vessels; and many of us enjoy eating seafood caught by noisy fishing boats, some of which even use dynamite to catch fish. We want to protect our borders, making naval operations a necessity. Then there’s the ever growing industry of marine tourism, much of it aboard ever-bigger cruise ships which need large ports in which to berth.
There are a lot of stakeholders in the marine environment, and all speak a different language, all make different claims, and all make noise. Knowing precisely how much noise they make, and how it affects marine life, will help to ensure our oceans and their resources last well into the future.
September 3-11 is SeaWeek 2016, the Australian Association for Environmental Education Marine Educators’ national public awareness campaign.
What we do on land has a real impact out on the reef: sediments can smother the corals, while high nutrient levels help to trigger more regular and larger outbreaks of crown-of-thorns starfish. This damage leaves the Great Barrier Reef even more vulnerable to climate change, storms, cyclones and other impacts.
Dealing with water quality alone isn’t enough to protect the reef, as many others have pointed out before. But it is an essential ingredient in making it more resilient.
The water quality targets call for sediment runoff to be reduced by up to 50% below 2009 levels by 2025, and for nitrogen levels to be cut by up to 80% over the same period. But so far, detailed information about the costs of achieving these targets has not been available.
Both the Australian and Queensland governments have committed more funding to improve water quality on the reef. In addition, the Queensland government established the Great Barrier Reef Water Science Taskforce, a panel of 21 experts from science, industry, conservation and government, led by Queensland Chief Scientist Geoff Garrett and funded by Queensland’s Department of Environment and Heritage Protection.
This groundbreaking study, which drew on the expertise of water quality researchers, economists and “paddock to reef” modellers, has found that investing A$8.2 billion would get us to those targets by the 2025 deadline, albeit with a little more to be done in the Wet Tropics.
That A$8.2 billion cost is half the size of the estimates of between A$16 billion and A$17 billion discussed in a draft-for-comment report produced in May 2016, which were reported by the ABC and other media.
Those draft figures did not take into account the reductions in pollution already achieved between 2009 and 2013. They also included full steps of measures that then exceeded the targets. A full review process identified these, and now this modelling gives a more accurate estimate of what it would cost to deliver the targets using the knowledge and technology available today.
A future for farming
Importantly, the research confirms that a well-managed agricultural sector can continue to coexist with a healthy reef through improvements to land management practices.
Even more heartening is the report’s finding that we can get halfway to the nitrogen and sediment targets by spending around A$600 million in the most cost-effective areas. This is very important because prioritising these areas enables significant improvement while allowing time to focus on finding solutions that will more cost-effectively close the remaining gap.
Among those priority solutions are improving land and farm management practices, such as adopting best management practices among cane growers to reduce fertiliser loss, and in grazing to reduce soil loss.
While these actions have been the focus of many water quality programs to date, much more can be done. For example, we can have a significant impact on pollutants in the Great Barrier Reef water catchments by achieving much higher levels of adoption and larger improvements to practices such as maintaining grass cover in grazing areas and reducing and better targeting fertiliser use in cane and other cropping settings. These activities will be a focus of the two major integrated projects that will result from the taskforce’s recommendations.
A new agenda
The new study, produced by environmental consultancy Alluvium and a range of other researchers (and for which I was one of the external peer reviewers), is significant because nothing on this scale involving the Great Barrier Reef and policy costings has been done before.
Alluvium’s consultants and other experts who contributed to the study – including researchers from CQ University and James Cook University – were asked to investigate how much could be achieved, and at what price, by action in the following seven areas:
Land management practice change for cane and grazing
Improved irrigation practices
Changes to land use
Urban stormwater management
Those seven areas for potential action were chosen on the basis of modelling data and expert opinion as the most feasible to achieve the level of change required to achieve the targets. By modelling the cost of delivering these areas and the change to nutrient and sediments entering the reef, the consultants were able to identify which activities were cheapest through to the most expensive across five catchment areas (Wet Tropics, Burdekin, Mackay-Whitsunday, Fitzroy and Burnett Mary).
Alluvium’s study confirmed the water science taskforce’s recommendation that investing in some catchments and activities along the Great Barrier Reef is likely to prove more valuable than in others, in both an environmental and economic sense.
Some actions have much lower costs and are more certain; these should be implemented first. Other actions are much more expensive. Of the total A$8.2 billion cost of meeting the targets, two-thirds (A$5.59 billion) could be spent on addressing gully remediation in just one water catchment (the Fitzroy region). Projects with such high costs are impractical and highly unlikely to be implemented at the scale required.
The Alluvium study suggests we would be wise not to invest too heavily in some costly repair measures such as wetland construction for nutrient removal just yet – at least until we have exhausted all of the cheaper options, tried to find other cost-effective ways of reaching the targets, and encouraged innovative landholders and other entrepreneurs to try their hand at finding ways to reduce costs.
The value of a healthier reef
The A$8.2 billion funding requirement between now and 2025 is large, but let’s look at it in context. It’s still significantly less than the A$13 billion that the Australian government is investing in the Murray-Darling Basin.
It would also be an important investment in protecting the more than A$5 billion a year that the reef generates for the Australian economy and for Queensland communities.
The immediate focus should be on better allocating available funds and looking for more effective solutions to meet the targets to protect the reef. More work is still needed to ensure we do so.
If we start by targeting the most cost-effective A$1 billion-worth of measures, that should get us more than halfway towards achieving the 2025 targets. The challenge now is to develop new ideas and solutions to deliver those expensive last steps in improving water quality. The Alluvium report provides a valuable tool long-term to ensure the most cost-effective interventions are chosen to protect the Great Barrier Reef.
This article was written with contributions from Geoff Garrett, Stuart Whitten, Steve Skull, Euan Morton, Tony Weber and Christine Williams.