The sweet relief of rain after bushfires threatens disaster for our rivers



After heavy rainfall, debris could wash into our waterways and threaten fish, water bugs, and other aquatic species.
Jarod Lyon, Author provided

Paul McInerney, CSIRO; Gavin Rees, CSIRO, and Klaus Joehnk, CSIRO

When heavy rainfall eventually extinguishes the flames ravaging south-east Australia, another ecological threat will arise. Sediment, ash and debris washing into our waterways, particularly in the Murray-Darling Basin, may decimate aquatic life.

We’ve seen this before. Following 2003 bushfires in Victoria’s alpine region, water filled with sediment and debris (known as sediment slugs) flowed into rivers and lakes, heavily reducing fish populations. We’ll likely see it again after this season’s bushfire emergency.




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The bushfires are horrendous, but expect cyclones, floods and heatwaves too


Large areas of northeast Victoria have been burnt. While this region accounts only for 2% of Murray-Darling Basin’s entire land area, water flowing in from northeast Victorian streams (also known as in-flow) contributes 38% of overall in-flows into the Murray-Darling Basin.

Fire debris flowing into Murray-Darling Basin will exacerbate the risk of fish and other aquatic life dying en masse as witnessed in previous years..

What will flow into waterways?

Generally, bushfire ash comprises organic carbon and inorganic elements such as nitrogen, phosphorous and metals such as copper, mercury and zinc.

Sediment rushing into waterways can also contain large amounts of soil, since fire has consumed the vegetation that once bound the soil together and prevented erosion.

And carcinogenic chemicals – found in soil and ash in higher amounts following bushfires – can contaminate streams and reservoirs over the first year after the fire.

A 2014 post-fire flood in a Californian stream.

How they harm aquatic life

Immediately following the bushfires, we expect to see an increase in streamflow when it rains, because burnt soil repels, not absorbs, water.

When vast amounts of carbon are present in a waterway, such as when carbon-loaded sediments and debris wash in, bacteria rapidly consumes the water’s oxygen. The remaining oxygen levels can fall below what most invertebrates and fish can tolerate.

These high sediment loads can also suffocate aquatic animals with a fine layer of silt which coats their gills and other breathing structures.

Habitats are also at risk. When sediment is suspended in the river and light can’t penetrate, suitable fish habitat is diminished. The murkier water also means there’s less opportunity for aquatic plants and algae to photosynthesise (turn sunshine to energy).




Read more:
How wildfire smoke affects pets and other animals


What’s more, many of Australia’s waterbugs, the keystone of river food webs, need pools with litter and debris for cover. They rely on slime on the surface of rocks and snags that contain algae, fungi and bacteria for food.

But heavy rain following fire can lead to pools and the spaces between cobbles to fill with silt, causing the waterbugs to starve and lose their homes.

This is bad news for fish too. Any bug-eating fish that manage to avoid dying from a lack of oxygen can be faced with an immediate food shortage.

Many fish were killed in Ovens River after the 2003 bushfires from sediment slugs.
Arthur Rylah Institute, Author provided

We saw this in 2003 after the sediment slug penetrated the Ovens River in the north east Murray catchment. Researchers observed dead fish, stressed fish gulping at the water surface and freshwater crayfish walking out of the stream.

Long-term damage

Bushfires can increase the amount of nutrients in streams 100 fold. The effects can persist for several years before nutrient levels return to pre-fire conditions.

More nutrients in the water might sound like a good thing, but when there’s too much (especially nitrogen and phosphorous), coupled with warm temperatures, they can lead to excessive growth of blue-green algae. This algae can be toxic to both people and animals and often closes down recreational waters.




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Strength from perpetual grief: how Aboriginal people experience the bushfire crisis


Large parts of the upper Murray River catchment above Lake Hume has burnt, risking increases to nutrient loads within the lake and causing blue-green algae blooms which may flow downstream. This can impact communities from Albury all the way to the mouth of the Murray River in South Australia.

Some aquatic species are already teetering on the edge of their preferred temperature as stream temperatures rise from climate change. In places where bushfires have burnt all the way to the stream edge, decimating vegetation that provided shade, there’ll be less resistance to temperature changes, and fewer cold places for aquatic life to hide.

Cooler hide-outs are particularly important for popular angling species such as trout, which are highly sensitive to increased water temperature.

Ash blanketing the forest floor can end up in waterways when it rains.
Tarmo Raadik

But while we can expect an increase in stream flow from water-repellent burnt soil, we know from previous bushfires that, in the long-term, stream flow will drop.

This is because in the upper catchments, regenerating younger forests use more water than the older forests they replace from evapotranspiration (when plants release water vapour into the surrounding atmosphere, and evaporation from the surrounding land surface).

It’s particularly troubling for the Murray-Darling Basin, where large areas are already enduring ongoing drought. Bushfires may exacerbate existing dry conditions.

So what can we do?

We need to act as soon as possible. Understandably, priorities lie in removing the immediate and ongoing bushfire threat. But following that, we must improve sediment and erosion control to prevent debris being washed into water bodies in fire-affected areas.




Read more:
In fact, there’s plenty we can do to make future fires less likely


One of the first things we can do is to restore areas used for bushfire control lines and minimise the movement of soil along access tracks used for bushfire suppression. This can be achieved using sediment barriers and other erosion control measures in high risk areas.

Longer-term, we can re-establish vegetation along waterways to help buffer temperature extremes and sediment loads entering streams.

It’s also important to introduce strategic water quality monitoring programs that incorporate real-time sensing technology, providing an early warning system for poor water quality. This can help guide the management of our rivers and reservoirs in the years to come.

While our current focus is on putting the fires out, as it should be, it’s important to start thinking about the future and how to protect our waterways. Because inevitably, it will rain again.The Conversation

Paul McInerney, Research scientist, CSIRO; Gavin Rees, , CSIRO, and Klaus Joehnk, Senior research scientist, CSIRO

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

Even for an air pollution historian like me, these past weeks have been a shock



Throughout history, Australian bushfires have spread smoke over our cities. But this time it’s different.
David Mariuz/AAP

Nancy Cushing, University of Newcastle

Smoke from this season’s bushfires has turned the sun red, the moon orange and the sky an insipid grey. It has obscured iconic views tourists flock to see. Far more than an aesthetic problem, it has forced business shutdowns, triggered health problems and kept children indoors for weeks.

City dwellers in southeast Australia have been forced to take a crash course in the finer points of air pollution. We’ve learned about the dangers of inhaling tiny PM2.5 particles (those 2.5 microns or fewer in diameter). We’ve learned that only a close-fitting P2 mask will do much to protect us.

Still, we wear disposable paper masks and hold handkerchiefs to our faces, hoping any amount of filtering is helpful.

A police officer wears a mask while on duty at Parliament House in Canberra.
NARENDRA SHRESTHA/AAP

Even for an historian of air pollution like me, this situation is a shock. It is not the first time Australia’s major cities have been shrouded in bushfire smoke. But the terrible air quality is unmatched in terms of severity, duration and extent.

Historically, air pollution from smoke was considered outside human control and not subject to regulation. But these bushfires are clearly linked to global warming, for which government, corporations and individuals are responsible. It’s time to rethink the way we protect air quality.

The history of smoke

In recent weeks, apps such as AirVisual have confirmed what we city dwellers can already see and smell: since the fires on the north coast of NSW began in late October, our air quality has plummeted.

The New South Wales government’s Air Quality Index data has shown that since late October, days when the index was higher than 100 – signalling exposure is unhealthy – have outnumbered clear days in Sydney, Newcastle and the Illawarra.

Smoke emissions from the Australian bushfires from 1 December 2019 to 4 January 2020.

Index readings above 2,550 have been recorded in Sydney, while the Monash monitoring site in Canberra reached a choking 5,185 at 8pm on New Year’s Day.

Bushfire smoke has affected the cities of NSW and the Australian Capital Territory in the past. In late January 1926, when Canberra was just emerging as a city, a thick haze of smoke sat over the site. Fires came within metres of Yarralumla, the residence which, the following year, would become home to the Governor-General.

In several years in the mid 1930s, bushfires burning to the north of Sydney left the city air thick with smoke. In October 1936, bushfire smoke forced a motor liner arriving from Hong Kong to warily enter the harbour sounding its siren, because it was invisible to signallers on South Head.

A New Zealand pilot, flying into Sydney from Longreach the following month, had to fly blind in “great clouds of dense smoke” covering much of NSW. In 1939, Canberra was covered by what visiting writer HG Wells described as a “streaming smoke curtain”.




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In the summer of 1944, Sydney was again enveloped in a smoke haze, this time from fires in the Blue Mountains and (later Royal) National Park in November. Photographs published at the time show the Sydney Harbour Bridge barely visible through dust and smoke at midday. The ongoing fires were blamed for an increase in diseases of the ears, nose and throat, and for cases of influenza and pneumonia, leading to a shortage of hospital beds.

A satellite image showing fires burning on Australia’s east coast.
NASA EARTH OBSERVATORY

In November 1951, all of NSW was said to be blacked out by bushfire smoke. In Sydney on the worst days, records show all four of the city’s airfields were closed because of “smoke-fog”.

A hazy legal framework

In each of these episodes, bushfire smoke disrupted transport, commerce, health and the enjoyment of the urban environment. But even as other forms of air pollution began to be regulated, smoke from bushfires escaped legislative attention.

What was understood as air pollution were the unwanted byproducts of industrial processes, whereas bushfire smoke was viewed as natural.




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Pregnant women should take extra care to minimise their exposure to bushfire smoke


In NSW in 1866, an act based on British legislation restricted smoke from mills, distilleries and gas works. Further limitations on smoke production in built-up areas were included in later acts governing public health (1902), motor traffic (1909) and local government (1919).

After World War II Newcastle, the site of the country’s largest concentration of coal-burning heavy industry, began to pay closer attention to managing air quality. This pioneering work was given added urgency after 4,000 people died in heavy London smog in 1952.

A woman seen wearing a face mask as smoke haze from bushfires blankets Sydney.
JOEL CARRETT/AAP

In 1958, a NSW parliamentary committee delivered a report into smoke abatement. It did not mention recent issues with bushfire smoke, and also dismissed the impact of domestically produced smoke. The subsequent 1961 Clean Air Act focused on air pollution from industry, transport and power generation.

Air pollution legislation continued to evolve in following decades, targeting motor vehicle emissions in the 1970s, backyard burning of waste in the 1980s, and wood fires used to heat homes in the 1990s.

These measures have been successful. A 2006 study found that between 1998 and 2003, on the limited occasions when standards for PM10 in six Australian cities were exceeded, the main sources were not industry or transport, but dust storms and bushfires (with the exception of Launceston, where heating fires were the main contributor).

A young man jumps from a rock in Sydney during smoke haze.
Steven Saphore/AAP

Looking ahead

Today, bushfire smoke is excluded from air quality regulations, despite its obvious role in pollution. It is still considered natural, and beyond human control.

However the link between the current fires and human-caused climate change, long predicted by climate scientists, suggests this exemption is no longer valid.




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Our buildings aren’t made to keep out bushfire smoke. Here’s what you can do


As the Australian National University’s Tom Griffiths has written, the current fires in some ways repeat patterns of the past. But “the smoke is worse, more widespread and more enduring”.

When Australia begins the recovery from these fires, our business-as-usual approach requires a rethink. Measures to protect air quality should be a major part of this.

It is time that corporations, governments and societies which contribute to global heating be held to account for more frequent, intense and widespread bushfires, and the smoke which billows from them.The Conversation

Nancy Cushing, Associate professor, University of Newcastle

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

Climate explained: seven reasons to be wary of waste-to-energy proposals



Many developed countries already have significant waste-to-energy operations and therefore less material going to landfill.

Jeff Seadon, Auckland University of Technology


CC BY-ND

Climate Explained is a collaboration between The Conversation, Stuff and the New Zealand Science Media Centre to answer your questions about climate change.

If you have a question you’d like an expert to answer, please send it to climate.change@stuff.co.nz

I was in Switzerland recently and discovered that they haven’t had any landfill since the early 2000s, because all of their waste is either recycled or incinerated to produce electricity. How “green” is it to incinerate waste in order to produce electricity? Is it something New Zealand should consider, so that 1) we have no more landfill, and 2) we can replace our fossil-fuel power stations with power stations that incinerate waste?

Burning rubbish to generate electricity or heat sounds great: you get rid of all your waste and also get seemingly “sustainable” energy. What could be better?

Many developed countries already have significant “waste-to-energy” incineration plants and therefore less material going to landfill (although the ash has to be landfilled). These plants often have recycling industries attached to them, so that only non-recyclables end up in the furnace. If it is this good, why the opposition?

Here are seven reasons why caution is needed when considering waste-to-energy incineration plants.




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Stifling innovation and waste reduction

  1. Waste-to-energy plants require a high-volume, guaranteed waste stream for about 25 years to make them economically viable. If waste-to-energy companies divert large amounts of waste away from landfills, they need to somehow get more waste to maintain their expensive plants. For example, Sweden imports its waste from the UK to feed its “beasts”.

  2. The waste materials that are easiest to source and have buyers for recycling – like paper and plastic – also produce most energy when burned.

  3. Waste-to-energy destroys innovation in the waste sector. As a result of China not accepting our mixed plastics, people are now combining plastics with asphalt to make roads last longer and are making fence posts that could be replacing treated pine posts (which emit copper, chrome and arsenic into the ground). If a convenient waste-to-energy plant had been available, none of this would have happened.

  4. Waste-to-energy reduces jobs. Every job created in the incineration industry removes six jobs in landfill, 36 jobs in recycling and 296 jobs in the reuse industry.

  5. Waste-to-energy works against a circular economy, which tries to keep goods in circulation. Instead, it perpetuates our current make-use-dispose mentality.

  6. Waste-to-energy only makes marginal sense in economies that produce coal-fired electricity – and then only as a stop-gap measure until cleaner energy is available. New Zealand has a green electricity generation system, with about 86% already coming from renewable sources and a target of 100% renewable by 2035, so waste-to-energy would make it a less renewable energy economy.

  7. Lastly, burning waste and contaminated plastics creates a greater environmental impact than burning the equivalent oil they are made from. These impacts include the release of harmful substances like dioxins and vinyl chloride as well as mixtures of many other harmful substances used in making plastics, which are not present in oil.




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Landfills as mines of the future

European countries were driven to waste-to-energy as a result of a 2007 directive that imposed heavy penalties for countries that did not divert waste from landfills. The easiest way for those countries to comply was to install waste-to-energy plants, which meant their landfill waste dropped dramatically.

New Zealand does not have these sorts of directives and is in a better position to work towards reducing, reusing and recycling end-of-life materials, rather than sending them to an incinerator to recover some of the energy used to make them.

Is New Zealand significantly worse than Europe in managing waste? About a decade ago, a delegation from Switzerland visited New Zealand Ministry for the Environment officials to compare progress in each of the waste streams. Both parties were surprised to learn that they had managed to divert roughly the same amount of waste from landfill through different routes.

This shows that it is important New Zealand doesn’t blindly follow the route other countries have used and hope for the same results. Such is the case for waste-to-energy.

There is also an argument to be made for current landfills. Modern, sanitary landfills seal hazardous materials and waste stored over the last 50 years presents future possibilities of landfill mining.

Many landfills have higher concentrations of precious metals, particularly gold, than mines and some are being mined for those metals. As resources become scarcer and prices increase, our landfills may become the mines of the future.The Conversation

Jeff Seadon, Senior Lecturer, Auckland University of Technology

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

New Zealand poised to introduce clean car standards and incentives to cut emissions



Australia and Russia could soon be the last remaining developed nations without fuel efficiency standards, with New Zealand proposing new rules and financial incentives to get more people driving cleaner cars.
http://www.shutterstock.com, CC BY-ND

Robert McLachlan, Massey University

The New Zealand government has proposed new fuel standards to cut greenhouse emissions, along with consumer rebates for cleaner cars – paid for by fees on high-polluting cars.

The long-awaited proposed changes would bring New Zealand in line with most other developed countries; apart from New Zealand, Russia and Australia are the last remaining OECD nations without fuel efficiency standards.

New Zealand’s long tradition of not regulating its car market, combined with substantial indirect subsidies for private cars, makes addressing emissions from the transport sector both challenging and highly significant.




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New Zealand’s second-rate car fleet

Land transport emissions – the single largest source of fossil carbon dioxide in New Zealand – grew 93% between 1990 and 2017. There are multiple causes. The population grew 44% during this period, mostly through immigration. The car ownership rate also grew rapidly, partly due to economic growth and deficiencies in public transport in the main cities. Car ownership in New Zealand is now the highest in the OECD and there are more motor vehicles than adults.

Fuel efficiency improved only slowly over this period, before stalling in recent years: at 180g CO₂/km, the emissions of newly imported vehicles in New Zealand are 50% higher than in Europe. Because of the lack of a fuel efficiency standard, importers provide less efficient versions of their bestsellers to the New Zealand market. Of the ten bestselling new vehicles, five are utes (which also benefit from a fringe benefit tax exemption, four are SUVs and one is a regular car.

In addition, half of all vehicles are imported secondhand, mostly from Japan. They are cheap, but less efficient than newer models. Emissions, and congestion, are likely to continue rising as the national vehicle fleet is increasing by 110,000 vehicles a year.

One bright spot in the present situation is the emergence of an electric vehicle segment, mostly driven by the availability of cheap second-hand Nissan Leafs from Japan and the construction of a fast-charging network by a private company. Although sales have stalled in the past year at a market share of 2%, there are now 15,000 electric vehicles in New Zealand. (Australia has around 10,000 electric vehicles.)

New Zealand’s history of fuel taxes

New Zealand does not have a strong record of taxing “bads”. The only goods subject to excise taxes are tobacco, alcohol and fuel. The fuel tax is moderate by international standards. Over the past decade, the fuel tax has been fully allocated to road construction and maintenance.

New Zealand has an emissions trading scheme. The current carbon price of NZ$25/tonne of carbon dioxide adds five cents per litre to the price of fuel. Clearly, any likely increases in the carbon price are not going to be enough to change car buying decisions. Research shows that consumers tend to focus on upfront costs, while underestimating future fuel and maintenance costs.

Despite that, a special Auckland fuel tax of 10 cents per litre that co-funds public transport investment provoked a brief but intense backlash from the public. Plans to extend the scheme to other centres were canned.

A two-pronged plan

The proposed fuel efficiency standard would require car importers to either meet it or pay a fine. The suggested standard is 150gCO₂/km in 2021, falling to 105gCO₂/km in 2025, with further falls thereafter. There are more than 3000 car importers in New Zealand, so this could prompt a major shakeup, including possible price adjustments.

The standards are similar to those proposed by the Australian Coalition government in 2016, which have not yet been taken any further. Internationally, fuel efficiency standards cover 80% of the light vehicle market.




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Australians could have saved over $1 billion in fuel if car emissions standards were introduced 3 years ago


But the second component of the proposal, the clean car discount, has attracted more attention. Cars emitting less than the current threshold would received a discount, initially up to NZ$1800 for an efficient petrol car, up to NZ$4800 for a hybrid and up to NZ$8000 for a battery electric car. Cars costing more than NZ$80,000 would not receive a discount.

Known as a “feebate scheme”, those rebates would be paid for by increased fees for high-polluting cars, of up to NZ$3000. The amounts are designed so that the entire scheme would be revenue neutral to the government. Modelling suggests that the proposed standard and discount combined would save motorists NZ$12,000 over the life of a vehicle.

International clean car schemes and testing

There is international experience with similar schemes, and they have been broadly effective. France has been operating a “feebate” scheme since 2008 with periodic adjustments. New Zealand’s proposed scheme is similar to the French and Swedish schemes.

But there is also room to get it wrong. Tinkering with electric vehicle incentives has led to wild sales fluctuations in the Netherlands and Denmark.

The spread between tested and real-world fuel use has widened, up from 9% in 2001 to 42%. The new Worldwide Harmonised Light Vehicle Test Procedure testing cycle, currently being adopted by Japanese and European manufacturers, is believed to be more representative of real-world fuel use, as is the test already in use in the United States.

But overall, the New Zealand proposal has been received positively by car makers and across political parties.

One possible weakness is that it is entirely based on carbon dioxide. Other pollutants, including nitrous and sulphur oxides and particulate matter (soot), that are responsible for most of the immediate health impacts of vehicle pollution and are worse in diesel than in petrol vehicles, are not targeted. Nor are the underlying subsidies to the car-based transport system, which make a transition to active and public transport more difficult.

Any decisions made now will have impacts for decades to come. Switching the fleet to electric is different from just switching to more fuel-efficient cars. It involves new charging infrastructure and some behavioural changes from the public, and these challenges (rather than simply cost) are stumbling blocks worldwide to more rapid adoption.

These arguments have persuaded many countries to bring in electric vehicle incentives beyond simply targeting carbon dioxide. Norway is a famous example, where electric vehicles avoid purchase taxes and market share is already 60%. The UK has recently exempted electric company cars from fringe benefit tax.

As the global market share of electric vehicles still stands at only 2%, eight years after they became widely available, and the number of fossil-fueled vehicles is increasing by 48 million a year, stronger action on vehicle emissions is clearly needed worldwide.The Conversation

Robert McLachlan, Professor in Applied Mathematics, Massey University

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

Lights out! Clownfish can only hatch in the dark – which light pollution is taking away



Some 22% of the worlds’ coastlines are exposed to artificial light at night.
Emily Fobert, Author provided

Emily Fobert, Flinders University

Clownfish achieved worldwide fame following Finding Nemo, but it turns out these fish don’t do so well in the spotlight.

Our research, published in Biology Letters, found when clownfish eggs were exposed to low levels of light at night – as they would be if laid near a coastal town – not a single egg hatched.

This finding adds to the growing body of research on the health affects of light pollution, a rapidly spreading ecological problem.




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Light pollution: the dark side of keeping the lights on


What is light pollution?

Light pollution occurs when artificial light interferes with ecological systems or processes, usually at night.

Natural light at night, produced by the moon, stars, and other celestial bodies, is minimal. A full moon creates only 0.05-0.1 lux, which pales in comparison to the artificial light produced by humans, which can range from around 10 lux from an LED or low-pressure sodium streetlight, up to 2,000 lux from something like stadium lighting.

Clownfish were exposed to artificial light to see what effect it would have on their reproduction.
Emily Fobert, Author provided

Because nearly all organisms on Earth have evolved with a stable day-night, light and dark cycle, many biological events are now highly attuned to the daily, lunar, and seasonal changes in light produced by the reliable movements of the Earth and Moon around the Sun.

But artificial light can mask these natural light rhythms and interfere with the behaviour and physiology of individual creatures, and ecosystems as a whole.

The ocean is not exempt from these problems. Light pollution is spreading to marine habitats through urbanised coastlines and increasing marine infrastructure such as piers, harbours, cruise ships, and tropical island resorts where bungalows extend out into the lagoon, directly above coral reefs.

Why are clownfish at risk?

Clownfish, like many reef fish, are particularly vulnerable to light pollution because they don’t move around much in their adult stage. Clownfish can travel long distances in the first 2 weeks after hatching, but at the end of this period the young fish will settle in a suitable sea anemone that becomes their forever-home.

Once clownfish find a suitable anemone they stay put forever.
Emily Fobert, Author provided

This means that if a fish chooses an anemone on a shallow reef in an area that is heavily lit at night, they will experience chronic exposure to light pollution throughout their life; they won’t just move away.

Clownfish also lay their eggs attached to rock or other hard surfaces, so in areas exposed to light pollution the eggs will experience continuous artificial light (as opposed to many fish that lay and fertilise eggs in open water, so they are immediately carried away by ocean currents).

What we found

To test how artificial light affects clownfish reproduction, we examined the common clownfish (Amphiprion ocellaris) in a lab experiment.

Five breeding pairs of fish experienced a normal 12-hour daylight, 12-hour dark cycle, while another five pairs of fish had their “night” period replaced with 12 hours of light at 26.5 lux, mimicking light pollution from an average coastal town.

For 60 days, we monitored how often the fish spawned, how many eggs were fertilised, and how many eggs hatched. While we saw no difference in spawning frequency or fertilisation rates between the two groups of fish, the impact of the artificial light treatment on hatch rate was staggering. None of the eggs hatched, compared with an average of 86% in the control group.

Clownfish attach their eggs to rocks or other hard surfaces, leaving them at the mercy of their immediate environmental conditions.
Emily Frobert, Author provided



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At the end of the experiment we removed the artificial light and monitored the fish for another 60 days to see how they would recover. As soon as the light at night was removed, eggs resumed hatching at normal rates.

Clownfish, like many reef fish, have evolved to hatch after dusk to avoid the threat of being eaten. Newly hatched baby clownfish, like most coral reef fish, are small (about 5mm long) and transparent. Hatching in darkness likely means they are less visible to predators as they emerge from their eggs.

Our findings show that the presence of artificial light, even at relatively low levels, can disrupt this crucial process, by masking the environmental cue – darkness – that triggers hatching. As many reef fish share similar reproductive behaviours to clownfish, it is likely artificial light will similarly interfere with the ability of other fish species to produce viable offspring.

Healthy, fertilised clownfish eggs did not hatch in the presence of artificial light.
Emily Frobert, Author provided

The larger problem

Light pollution is one of the most pervasive forms of environmental change. An estimated 23% of land surface (excluding the poles) and 22% of coastal regions are exposed to light pollution.

And the problem is only growing. The reach of light pollution across all land and sea is expanding at an estimated rate of 2.2% per year, and this will only increase with the rising global human population.




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Saving Nemo: how climate change threatens anemonefish and their homes


Although research on the ecological impacts of light pollution is arguably only in its infancy, the evidence for negative consequences for a range of insects, birds, amphibians, reptiles, and mammals, including humans, is stacking up.

Our new research adds another species to the list, and highlights the importance of finding ways to manage or reduce artificial light, on land and below the waves.The Conversation

Emily Fobert, Research Associate, Flinders University

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

Australia’s pristine beaches have a poo problem



Raw sewage from 3,500 people in Sydney’s affluent eastern suburbs is discharged directly into the ocean.
Will Turner/Unsplash

Ian Wright, Western Sydney University; Andrew Fischer, University of Tasmania; Boyd Dirk Blackwell, University of Tasmania; Qurratu A’yunin Rohmana, University of Tasmania, and Simon Toze, CSIRO

Australians love our iconic coastal lifestyle. So many of our settlements are spread along our huge coastline. Real estate prices soar where we can catch a view of the water.

But where there are crowded communities, there is sewage. And along the coast it brings a suite of problems associated with managing waste, keeping the marine environment healthy, and keeping recreational swimmers safe.




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Sewage is not a sexy topic. People often have an “out of sight, out of mind” attitude. But where does sewage go, and is it treated and disposed of in the waters that we Australians love?

The bigger the coastal community, the bigger the volume of sewage. Disposal of human waste into the ocean might solve one problem, but we now realise that the “waste” is as precious as the ocean it pollutes.

We should be treating and recycling sewage to a drinkable level.
shutterstock

Understanding the problem from a national perspective

Such problems play out continuously along our coastline. Each isolated community and catchment issue arises and is resolved, often in ignorance of and isolation from similar issues somewhere else.

At present, places where sewage impacts are generating community concern include Merimbula, Warrnambool and, perhaps most bizarrely, Vaucluse and Diamond Bay in Sydney’s affluent eastern suburbs.

It’s hard to believe this location has raw and untreated sewage from 3,500 people discharged directly into the Tasman Sea. Sydney Water pledged in 2018 to fix this unsightly pollution by transferring the flow to the nearby Bondi sewage treatment plant.

Community group Clean Ocean Foundation has worked with the Marine Biodiversity Hub to start the process of viewing outfall pollution – where a drain or sewer empties into the sea – as part of a bigger picture. It’s a first step towards understanding from a national perspective.




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Together they have produced the National Outfall Database to provide the first Australia-wide comparison.

The best and worst offenders

Previously the information available to the public was sketchy and often not easily accessed. The database shows how differently Australia manages coastal sewage with information on the outfalls.

Clean Ocean Foundation CEO John Gemmill said:

Water authorities in the main do a great job with severe funding constraints. But they can be reticent to divulge information publicly.

One authority, suspicious of the research project, initially refused to give the location of the outfall, claiming it would be vandalised by enraged “surfies and fishermen”.

Sydney has Australia’s biggest outfall. It provides primary treatment at Malabar, New South Wales, and serves about 1.7 million people. The outfall releases about 499 megalitres (ML) per day of treated sewage, called “effluent”.

That’s about eight Olympic-sized swimming pools of effluent an hour. It is discharged to the Pacific Ocean 3.6 kilometres from the shoreline at a depth of 82 metres.

The cleanest outfall (after sustained advocacy over decades from the Clean Ocean Foundation) is Boags Rock, in southern Melbourne. It releases tertiary-treated sewage with Class A+ water. This means the quality is very suitable for reuse and has no faecal bacteria detected (Enterococci or E.coli).

Recycling sewage

Treated sewage is 99% water. The last 1% is what determines if the water will harm human and environmental health. Are we wasting a precious resource by disposing of it in the ocean?

As desalination plants are cranking up in Sydney and Melbourne to extract pure water from salty ocean, why shouldn’t we also recycle sewage?




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More of us are drinking recycled sewage water than most people realise


Clean Ocean Foundation has released a report showing it would pay to treat sewage more thoroughly and reuse it. This report finds upgrading coastal sewage outfalls to a higher level of treatment will provide tens of billions of dollars in benefits.

Industry analysis suggests that, for a cost outlay of between A$7.3 billion and A$10 billion, sewage treatment upgrades can deliver between A$12 billion and A$28 billion in net benefits – that is, the financial benefits above and beyond what it cost to put new infrastructure in place.

Then there are non-economic benefits such as improved ecological and human health, and improved recreational and tourism opportunities by use of suitable recycling processes.

What the rest of Australia can learn from WA

Clean Ocean Foundation president Peter Smith said Australia’s key decision-makers now, more than before, have a “golden opportunity” to adopt a sea change in water reform around coastal Australia based on good science and sound economic analysis.

In the context of the drought of southeast Australia, recycling water from ocean outfalls is an option that demands further debate.




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Finally facing our water-loo: it’s time to decolonise sewerage systems


As expensive desalination plants are switched on, Sydney proposes to double the size of its desalination plant – just a few kilometres from massive ocean outfalls that could provide so much recycled water. And to our shame, NSW ocean outfalls are among the lowest in standards of treatment.

Western Australia, on the other hand, leads the push to recycle wastewater as it continues to struggle with diminishing surface water from climate change.

In fact, in 2017 the Water Corporation announced massive investment in highly treated sewage being used to replenish groundwater supplies. Perth now sources 20% of its drinking water from groundwater, reducing its reliance on two desalination plants. A key factor was successful engagement with affected communities.

The discharge of poorly treated sewage to rivers, estuaries and oceans is a matter of national environmental significance and the Commonwealth should take a coordinating role.

Our oceans do not respect state boundaries. The time is ripe for a deliberate national approach to recycling sewage and improved systems to manage outfalls.The Conversation

Ian Wright, Senior Lecturer in Environmental Science, Western Sydney University; Andrew Fischer, Senior Lecturer, University of Tasmania; Boyd Dirk Blackwell, Adjunct Researcher, University of Tasmania; Qurratu A’yunin Rohmana, Research Analyst, University of Tasmania, and Simon Toze, Senior Principal Research Scientist, CSIRO

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

Australians could have saved over $1 billion in fuel if car emissions standards were introduced 3 years ago



Legislative action regarding vehicle emissions is overdue, and needs urgent attention by the federal government.
Shutterstock

Robin Smit, The University of Queensland; Jake Whitehead, The University of Queensland, and Nic Surawski, University of Technology Sydney

When it comes to road transport, Australia is at risk of becoming a climate villain as we lag behind international best practice on fuel efficiency.

Road transport is one of the main sources of greenhouse gas emissions and represented 16% of Australia’s total carbon dioxide emissions in 2000, growing to 21% in 2016. Total CO₂ emissions from road transport increased by almost 30% in the period 2000-16.

Fuel efficiency (CO₂ emission) standards have been adopted in around 80% of the global light vehicle market to cap the growth of transport emissions. This includes the United States, the European Union, Canada, Japan, China, South Korea and India – but not Australia.




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Emissions standards on cars will save Australians billions of dollars, and help meet our climate targets


If Australia had introduced internationally harmonised emissions legislation three years ago, households could have made savings on fuel costs to the tune of A$1 billion.

This shocking figure comes from our preliminary calculations looking at the effect of requiring more efficient vehicles to be sold in Australia.

A report, published yesterday by Transport Energy/Emission Research, looked at what Australia has achieved in vehicle fuel efficiency and CO₂ standards over the past 20 years. While Australia has considered and tried to impose standards a number of times, sadly these attempts were unsuccessful.

Legislative action on vehicle CO₂ emissions is long overdue and demands urgent attention by the Australian government.

Australian consumers are increasingly buying heavier vehicles with bigger emissions.
Shuterstock

How did Australia get here?

The most efficient versions of vehicle models offered in Australia are considerably less efficient than similar vehicles in other markets.

Australia could increasingly become a dumping ground for the world’s least efficient vehicles with sub-par emissions performance, given our lack of fuel efficiency standards. This leaves us on a dangerous path towards not only higher vehicle emissions, but also higher fuel costs for passenger travel and freight.

Australia has attempted to impose CO₂ or fuel efficiency standards on light vehicles several times over the past 20 years, but without success. While the federal government was committed to addressing this issue in 2015, four years later we are still yet to hear when – or even if – mandatory fuel efficiency standards will ever be introduced.

The general expectation appears to be that average CO₂ emission rates of new cars in Australia will reduce over time as technology advances overseas. In the absence of CO₂ standards locally, it is more likely that consumers will continue to not be offered more efficient cars, and pay higher fuel costs as a consequence.

Estimating the fuel savings

Available evidence suggests Australian motorists are paying on average almost 30% more for fuel than they should because of the lack of fuel efficiency standards.

The Australian vehicle fleet uses about 32 billion litres of fuel per year.

Using an Australian fleet model described in the TER report, we can make a conservative estimate that the passenger vehicle fleet uses about half of this fuel: 16 billion litres per year. New cars entering the fleet each year would represent about 5% of this: 800 million litres per year.

So assuming that mandatory CO₂ standards improve fuel efficiency by 27%, fuel savings would be 216 million litres per year.

In the last three years, the average fuel price across Australia’s five major cities is A$1.33 per litre. This equates to a total savings of A$287 million per year, although this would be about half the first year as new cars are purchased throughout the year and travel less, and would reduce as vehicles travel less when they age.

The savings are accumulative because a car purchased in a particular year continues to save fuel over the following years.

The table below shows a rough calculation of savings over the three year period (2016-2018), for new cars sold in the same period (Model Years 2016, 2017 and 2018).

As a result, over a period of three years, A$1.3 billion in potential savings for car owners would have accumulated.

Policy has come close, but what are we waiting for?

The Australian government is not progressing any measures to introduce a fuel efficiency target. In fact, it recently labelled Labor’s proposed fuel efficiency standard as a “car tax”.

But Australia has come close to adopting mandatory vehicle CO₂ emission standards in the past.

In late 2007, the Labor government committed to cutting emissions to achieve Australia’s obligations under the Kyoto Protocol. The then prime minister, Kevin Rudd, instructed the Vehicle Efficiency Working Group to:

… develop jointly a package of vehicle fuel efficiency measures designed to move Australia towards international best practice.

Then, in 2010, the Labor government decided mandatory CO₂ emissions standards would apply to new light vehicles from 2015. But a change in government in 2013 meant these standards did not see the light of day.

The amount of fuel that could have been saved is A$287 million per year.
Shutterstock

Things looked promising again when the Coalition government released a Vehicle Emissions Discussion Paper in 2016, followed by a draft Regulation Impact Statement in the same year.

The targets for adopting this policy in 2025, considered in the draft statement, were marked as “strong” (105g of CO₂ per km), “medium” (119g/km) and “mild” (135g/km) standards.

Under all three targets, there would be significant net cost savings. But since 2016, the federal government has taken no further action.

It begs the question: what exactly are we waiting for?

The technical state of play

Transport Energy/Emission Research conducted preliminary modelling of Australian real-world CO₂ emissions.

This research suggests average CO₂ emission rates of the on-road car fleet in Australia are actually increasing over time and are, in reality, higher than what is officially reported in laboratory emissions tests.

In fact, the gap between mean real-world emissions and the official laboratory tests is expected to grow from 20% in 2010 to 65% in 2025.

This gap is particularly concerning when we look at the lack of support for low-emissions vehicles like electric cars.




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Given that fleet turnover is slow, the benefits of fuel efficiency standards would only begin to have a significant effect several years into the future.

With continuing population growth, road travel will only increase further. This will put even more pressure on the need to reduce average real-world CO₂ emission rates, given the increasing environmental and health impacts of the vehicle fleet.

Even if the need to reduce emissions doesn’t convince you, the cost benefits of emissions standards should. The sale of less efficient vehicles in Australia means higher weekly fuel costs for car owners, which could be avoided with the introduction of internationally harmonised emissions legislation.The Conversation

Robin Smit, Adjunct professor, The University of Queensland; Jake Whitehead, Research Fellow, The University of Queensland, and Nic Surawski, Lecturer in Environmental Engineering, University of Technology Sydney

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