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Life along the vanishing shorelines of the Solomon Islands – in pictures
Trees, graveyards and everyday life are being encroached upon by rising sea levels on the Solomon Islands. Local people are trying to adapt
Continue reading...We need more than just extra water to save the Murray-Darling Basin
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After a long and contentious public debate, in 2012 Australia embarked on a significant and expensive water recovery program to restore the Murray-Darling Basin’s ecosystems.
Despite general agreement that a certain amount of water should be reserved to restore the flagging river system, the argument continues as to whether this should be 2,750 or 3,200 gigalitres (GL) a year, and how these savings can be achieved.
A recent report by the Wentworth Group of Concerned Scientists argues that there is no conclusive evidence, after five years, that the plan is effective. The report’s authors believe that an extra 450GL of water a year needs to be recovered to save the basin.
There is no doubt in our minds that the Murray-Darling river system is in crisis, and the Basin Plan was vitally needed. But while we broadly agree with the Wentworth Group’s report, it’s a mistake to focus on water volume alone.
Without giving equal attention to improving water quality and building critical ecological infrastructure, it’s possible that increasing river flows could actually harm the Basin.
What are we trying to recover?We don’t really have much information on the state of the basin before industrial development. Most knowledge is more recent, but we do know that from about the 1920s onwards, considerable volumes of water have been removed. Few comprehensive historic records of flora and fauna, let alone water quality, are available.
While knowledge of the state and significance of the ecology of the river systems is scant, there is ample evidence that increased levels of nutrients, salts and, in particular, sediments have adversely affected the wetlands, main channels and associated floodplains.
The records of fish that historically lived in the rivers, billabongs and wetlands also tell a cautionary tale. These wetlands and rivers once teemed with native fish. In 1915, a single scoop of a 10 m seine net would yield more than 100,000 native fish in a single wetland.
There were dozens of species at each site, supporting a burgeoning fishery that was considered inexhaustible.
![](https://cdn.theconversation.com/files/176363/width754/file-20170630-2996-1d87lfz.png)
Since that time the basin has been extensively developed. The fishing industry expanded, forests were cleared, dams were built, floodplains were blocked by levies, water began to be diverted for irrigation, the demand for drinking water increased and invasive species were introduced. But somewhere over the past 100 years we crossed a threshold where the system stopped being able to support native fish.
Nowadays, visiting the wetlands that were historically packed with native fish (all of which had huge cultural importance to traditional owners), we find mostly invasive species such as carp, goldfish and weatherloach.
In some places, native species that were once abundant have not been seen in 40 years. The formerly productive commercial fisheries, and the livelihoods they supported, have been shut down.
Our native fish are in trouble, and unless urgent action is taken, many face extinction within decades.
Rebuilding a complex systemThe Basin Plan is underpinned by a focus on river volume as the cause of system degradation and subsequent recovery. But the system is much more complex than that. Fluctuating levels of sediments, salts and nutrients drive significant changes, and so regulating river flows – which carry these components from place to place – fundamentally alters the dynamics of main channels and floodplain wetlands.
Over the last century, erosion has filled the rivers in the Murray system with mud. When this water flows into the wetlands, this sediment builds and blocks the light, killing the aquatic plants that support native fish.
Simply increasing the water flow without addressing water quality runs the risk of exacerbating this problem. We therefore argue the first step in river recovery is attending to water quality.
The Murray-Darling Basin Plan has focused very heavily on the amount of water in the system; partly because speaking in terms of volume is easiest to demonstrate and understand. But the paleoecological record reveals that water quality, at least in wetlands, declined well before human use of water changed the river flows.
So if recovering water volume is a critical target, it is equally important that this water is of good quality. Recent experience with blackwater events, in which oxygen levels drop so low that fish suffocate, highlights this need. Even water of the wrong temperature, known as “thermal pollution”, can cause real harm. Winter-temperature water, for example, can prevent fish from breeding if it occurs in summer. Bad water quality will simply not provide good ecological outcomes.
A century of engineering development has fundamentally changed the basins rivers in a way that does not support native fish or the original ecology in general. Even if the recovered water is of high quality, we will need to take other steps to achieve tangible outcomes. Thus we need “complementary measures”, which augment the benefits of increasing river volumes. These include:
- Mitigating thermal and other pollution to ensure the water temperature and overall quality is adequate,
- Building fishways so that fish can navigate dams and weirs,
- Restocking threatened fish species into areas they are no longer found,
- Controlling carp and other non-native species that now dominate our waterways;
- Building fish-friendly irrigation infrastructure such as screens on irrigation pumps or overshot weirs; and
- Improving habitat through resnagging or controlling harmful practices on flood plains.
Another measure to improve the basin’s waterways, the proposal to release a virulent strain of carp herpes, has raised debate over whether it will neatly solve a major environmental and economic problem or create further issues.
If implemented correctly, these complementary measures are just as important as water recovery and improving water quality for meeting the basin plan’s ecological targets.
Repairing a river system such as the Murray-Darling is incredibly complex, and we must broaden our view beyond simply thinking about water volumes. Some of these extra steps can also provide benefits with less cost to the people who live and work with the water. To achieve this we suggest a staged program of recovery that allows the communities who live in the basin more time to adapt to the plan.
![The Conversation](https://counter.theconversation.edu.au/content/80188/count.gif)
Max Finlayson receives funding from the Australian Centre for International Agricultural Research and the Australian Research Council.
Lee Baumgartner works with the Fisheries Research and Development Corporation to investigate the benefits of complementary measures across the basin, including the release of the carp virus.
Peter Gell received funding from ARC to fund previous research into the Murray-Darling Basin. He currently receives funding from the NSW state government for research into wetlands. He is a member of the Greens.
The house that Tateh built ... out of sand-filled plastic bottles
In the Sahrawi refugee camps in the Algerian desert, Tateh Lehbib Braica – aka ‘the crazy bottle guy’ – has built circular houses from waste plastic that protect from wind and sun
A group of women drink tea under the shade of a tent and cast an eye over the construction of an odd, circular house. The half-built dwelling is the brainchild of Tateh Lehbib Braica, 27, an engineer who wanders among the workers.
On the ground lie hundreds of sand-filled, 1.5 litre plastic bottles that serve as bricks. With them, Tateh has found a way to fight back against the harshness of the Algerian desert that is home to 90,000 long-term refugees from western Sahara. It’s not yet that hot, but in summer, when the temperature rises above 50C, it will be impossible to venture out of doors.
Continue reading...Fine motorists idling outside schools to cut air pollution, say health watchdogs
New official guidance also backs planting trees, supporting cycling and encouraging take-up of electric vehicles to tackle crisis that causes 40,000 early deaths a year
Parents who leave their car engines running at the school gate should be fined in order to help tackle the air pollution crisis, according to England’s official health watchdogs.
New guidance from Public Health England (PHE) and the National Institute for Health and Care Excellence (Nice) sets out a wide range of measures to cut air pollution, which is at illegal levels in almost 90% of urban areas.
Continue reading...WA garnet miner to build 3MW solar, wind, battery storage plant
Spiky stars of summer's golden gang
Airedale, West Yorkshire Goldfinches bicker among the chromium yellows of gorse and laburnum
It’s been a good year for gorse. Perhaps the dryish winter helped. All across the north of England I’ve seen the plant’s reckless spatters of chromium yellow bristling with the promise of stonechats and whitethroats.
Some trace the origins of the word gorse to an Anglo-Saxon word for wasteland (this, Ulex europaeus, is a species of poor soil and open skies) but others relate it ultimately to the Greek for hedgehog, which is much more satisfying.
Continue reading...Reclink Community Cup is Australia’s first carbon neutral certified community event!
Carbon Market Institute launches the Carbon Marketplace
Another blow to CCS, as EU power giants bow out of Dutch project
Electric vehicle charging networks rolled out across WA, Qld
Energy storage already cost-competitive in commercial sector, finds study
SolarCoin – the cryptocurrency earned by generating solar electricity
NSW Coalition: Time to move on from notion of “baseload”
Trump’s road to ‘energy dominance’ excludes renewables
Wild ducks caught on camera snacking on small birds
'Very strong' climate change signal in record June heat
Common pesticides can harm bees, but the jury is still out on a global ban
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Some of the world’s most widely used pesticides can be harmful to bees, according to the first large-scale studies aimed at measuring the impact of compounds called neonicotinoids on bees’ health. But the effects vary widely between different compounds and different countries, suggesting that more regional research will be needed to clarify the exact scale of the problem.
Neonicotinoids, which are typically coated onto seeds before planting rather than being sprayed onto crop plants, were developed with the aim of harming only those animals that eat the plants. But they are also found in the pollen and nectar of treated plants, potentially affecting beneficial organisms like bees.
Two papers published today in the journal Science report that neonicotinoids have negative effects on honey bees and wild bees in realistic field experiments. But the results are mixed and far from conclusive.
The concern about neonicotinoids prompted the European Union to impose a temporary moratorium in 2013 on the use of three key pesticides. In contrast, New Zealand’s government has joined with Australia in not imposing a ban. I think our governments have made exactly the right decision at this time.
Study confirms negative effectsOne of the studies, led by Nadejda Tsvetkov at York University, Canada, indicates that chronic exposure to neonicotinoids reduces honey bees’ health near Canadian corn fields.
This is consistent with many previous research findings showing that feeding on large amounts of neonicotinoids can be fatal to honey bee workers and queens.
For bees given a smaller dose, their foraging becomes less efficient. They undertake reduced hygienic behaviour in the hive and their immune system seems to be impaired. And their tolerance of other stressors bees experience in their environment, in this case a fungicide, is reduced.
The new Canadian study shows that field-realistic exposure to neonicotinoids can substantially reduce honey bees’ health.
Other results mixedThe other study, led by Ben Woodcock of Britain’s Natural Environment Research Council, describes research done on three different bee species in three different countries. It also attempted to use field-realistic exposure to neonicotinoids. Populations of honey bees, bumble bees and a solitary bee were followed in the United Kingdom, Hungary and Germany.
The team examined two neonicotinoid pesticides, and found a fascinatingly mixed bag of results. Both pesticides resulted in significantly reduced numbers of honey bee eggs being produced in Hungary. But exposure to both pesticides in Germany resulted in significantly more eggs being produced. Neonicotinoids also seemed to result in higher numbers of workers surviving winter in Germany.
In Hungary, fewer worker bees survived winter after exposure to one pesticide, but not the other. Similarly, in the United Kingdom, there were mostly negative but some positive effects of exposure to the different neonicotinoid pesticides.
The take-home message is that different neonicotinoids can have different effects, which can be very specific to the country of use. After reading these results, if I were a grower in Germany, I might start to question the European Union’s temporary moratorium.
Country-specific data neededThese studies highlight the need for data to allow countries like New Zealand and Australia to effectively manage the use of neonicotinoid pesticides. We need to know the effects of neonicotinoids in our specific environmental conditions and in the way we use them.
We also need to know what the effects would be if we took this group of pesticides away. I’ve read reports that growers in the UK have had to revert to broad-spectrum pesticides that are considered worse for the environment and mean they cannot grow certain crops.
In 2013, the Australian government undertook a review of neonicotinoids and the health of honey bees. This concluded that “the introduction of the neonicotinoids has led to an overall reduction in the risks to the agricultural environment from the application of insecticides”.
The review found little scientific evidence to show that the current use of neonicotinoids in Australia causes widespread harm to honey bees. The review stated that “the introduction of the neonicotinoid insecticides has brought a number of benefits, including that they are considerably less toxic to humans (and other mammals) than the organophosphorus and carbamate insecticides they have significantly replaced”.
Bees are up against itHoney bees in New Zealand have a plethora of known and scientifically demonstrated threats. These include invasive blood-sucking mites, and the deformed wing virus, which has been described as a key contributor to the collapse of bee colonies around the world.
New Zealand’s bees have bacterial pathogens like American foulbrood that results in beekeepers having to burn their bees and hives. Fungal diseases are widespread. We also have management issues with the higher-than-ever numbers of managed hives, which are often managed poorly and often overstocked. These are real and known issues affecting our honey bees now. We have data on these problems that can guide their management.
The new research will doubtless lead to calls from some quarters for Australia and New Zealand to ban neonicotinoid pesticides. I hope that the New Zealand and Australian governments act on studies like those published today, but I would be disappointed if that action was anything other than evidence- and science-based. Let’s gather the data specifically for each country, and then make a decision on whether and how to use these pesticides.
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Phil Lester has not received funding from pesticide companies. His work is funded from a number of government sources, including the Royal Society Te Aparangi and the National Science Challenge in New Zealand.
Large-scale study 'shows neonic pesticides harm bees'
Farmers join fight against Adani coalmine over environmental concerns
More than 2,000 farmers and agriculture leaders express concern proposed Carmichael coalmine could affect groundwater, biodiversity and climate change
A group of Australian farmers have joined the large coalition of groups fighting against Adani’s giant Carmichael coalmine, after they became concerned about the affects the mine would have on groundwater, biodiversity, rural communities and climate change.
Farmers for Climate Action – a group of more than 2,000 farmers and agriculture leaders concerned about climate change – became the newest group to join the Stop Adani alliance last week, at the same time as one of its members attracted more than 30,000 signatures to a petition calling on the Queensland premier, Annastacia Palaszczuk, to rescind her commitment to give Adani unlimited free access to groundwater used by farmers in the region.
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