Interrupted flows in the Murray River endanger frogs

17 01 2023

Flooding in the Murray-Darling Basin is creating ideal breeding conditions for many native species that have evolved to take advantage of temporary flood conditions. Led by PhD candidate Rupert Mathwin, our team developed virtual models of the Murray River to reveal a crucial link between natural flooding and the extinction risk of endangered southern bell frogs (Litoria raniformis; also known as growling grass frogs).

Southern bell frogs are one of Australia’s 100 Priority Threatened Species. This endangered frog breeds during spring and summer when water levels increase in their wetlands. However, the natural flooding patterns in Australia’s largest river system have been negatively impacted by expansive river regulation that some years, sees up to 60% of river water extracted for human use.

Our latest paper describes how we built computer simulations of Murray-Darling Basin wetlands filled with simulated southern bell frogs. By changing the simulation from natural to regulated conditions, we showed that modern conditions dramatically increase the extinction risk of these beloved frogs.

The data clearly indicate that successive dry years raise the probability of local extinction, and these effects are strongest in smaller wetlands. Larger wetlands and those with more frequent inundation are less prone to these effects, although they are not immune to them entirely. The models present a warning — we have greatly modified the way the river behaves, and the modern river cannot support the long-term survival of southern bell frogs.’

Read the rest of this entry »




The integrity battlefield: where science meets policy

4 03 2022

Professor Ross Thompson, University of Canberra


On the whole, I am inclined to conclude that my experience of academia and publishing my work has been largely benign. Despite having published 120-odd peer-reviewed papers, I can count the number of major disputes on one hand. Where there have been disagreements, they have centred on issues of content, and despite the odd grumble, things have rarely escalated to the ad hominem. I have certainly never experienced concerted attacks on my work.

But that changed recently. I work in water science, participating in and leading multi-disciplinary teams that do research directly relevant to water policy and management. My colleagues and I work closely with state and federal governments and are often funded by them through a variety of mechanisms. Our teams are a complex blend of scientists from universities, state and federal research agencies, and private-sector consultancies. Water is big business in Australia, and its management is particularly pertinent as the world’s driest inhabited continent struggles to come to terms with the impacts of climate change.

In the last 10 years, Australia has undergone a AU$16 billion program of water reform that has highlighted the extreme pressure on ecosystems, rural communities, and water-dependent industries. In 2019, two documentaries (Cash Splash and Pumped) broadcast by the Australian Broadcasting Corporation were highly critical of the  outcomes of water reform. A group of scientists involved in working on the Murray-Darling Basin were concerned enough about the accuracy of aspects of those stories to support Professor Rob Vertessy from the University of Melbourne in drafting an Open Letter in response. I was a co-author on that letter, and something into which I did not enter lightly. We were very concerned about being seen to advocate for any particular policy position, but were simultaneously committed to contributing to an informed public debate. A later investigation by the Australian Communications and Media Authority also highlighted concerns with the Cash Splash documentary.

Fast forward to 2021 and the publication of a paper by Colloff et al. (2021) in the Australasian Journal of Water Resources. In that paper, the authors were critical of the scientists that had contributed to the Open Letter and claimed they had been subject to “administrative capture” and “issue advocacy”. Administrative capture is defined here as:

Read the rest of this entry »




The sixth mass extinction is happening now, and it doesn’t look good for us

2 03 2022

Mounting evidence is pointing to the world having entered a sixth mass extinction. If the current rate of extinction continues we could lose most species by 2200. The implication for human health and wellbeing is dire, but not inevitable.

In the timeline of fossil evidence going right back to the first inkling of any life on Earth — over 3.5 billion years ago — almost 99 percent of all species that have ever existed are now extinct. That means that as species evolve over time — a process known as ‘speciation’ — they replace other species that go extinct.

Extinctions and speciations do not happen at uniform rates through time; instead, they tend to occur in large pulses interspersed by long periods of relative stability. These extinction pulses are what scientists refer to as mass extinction events.

The Cambrian explosion was a burst of speciation some 540 million years ago. Since then, at least five mass extinction events have been identified in the fossil record (and probably scores of smaller ones). Arguably the most infamous of these was when a giant asteroid smashed into Earth about 66 million years ago in what is now the Gulf of Mexico. The collision vapourised species immediately within the blast zone. Later, species were killed off by climate change arising from pulverised particulates suspended in the atmosphere, as well as intense volcano activity stimulated by the buckling of the Earth’s crust from the asteroid’s impact. Together, about 76 percent of all species around at the time went extinct, of which the disappearance of the dinosaurs is most well-known. But dinosaurs didn’t disappear altogether — the survivors just evolved into birds.

Read the rest of this entry »




How to avoid reduce the probability of being killed by a shark

31 03 2021

Easy. Don’t go swimming/surfing/snorkelling/diving in the ocean.


“Oh, shit”

Sure, that’s true, but if you’re like many Australians, the sea is not just a beautiful thing to look at from the window, it’s a way of life. Trying telling a surfer not to surf, or a diver not to dive. Good luck with that.

A few years ago, I joined a team of super-cool sharkologists led by Charlie ‘Aussie-by-way-of-Belgium shark-scientist extraordinaire Huveneers, and including Maddie ‘Chomp’ Thiele and Lauren ‘Acid’ Meyer — to publish the results of some of the first experimentally tested shark deterrents.

It turns out that many of the deterrents we tested failed to show any reduction in the probability of a shark biting, with only one type of electronic deterrent showing any effect at all (~ 60% reduction).

Great. But what might that mean in terms of how many people could be saved by wearing such electronic deterrents? While the probability of being bitten by a shark is low globally, even in Australia (despite public perceptions), we wondered if the number of lives saved and injuries avoided was substantial.

In a new paper just published today in Royal Society Open Science, we attempted to answer that question.

To predict how many people could avoid shark bites if they were using properly donned electronic deterrents that demonstrate some capacity to dissuade sharks from biting, we examined the century-scale time series of shark bites on humans in Australia. This database — the ‘Australian Shark Attack File‘ — is one of the most comprehensive databases of its kind.

Read the rest of this entry »




Plan B: COVID-19 challenges for field-based PhD students

8 12 2020

Originally published on the GEL.blog


Blistering heat, pouring rain, finding volunteers, submitting field-trip forms, forgetting equipment, data sheets blowing away in the wind — a field-based research project is hard at the best of times. Add white sharks into the mix and you start to question whether this project is even possible. These were some of my realisations when I started my Honours year studying shark deterrents. 

A specific memory from my first field expedition was setting off on a six-day boat trip with the comfortable sight of land getting smaller and smaller, in an already rough ocean, to find one of the most feared fish in the sea, the white shark. I was intimidated, but also excited. 

Over the next few days reality set in and I experienced the true challenges of working in the field. When there were no sharks around, I had to concentrate on the bait line for hours in anticipation of a sudden ambush. When there were sharks around, it was all systems go and there was no room for error — not with a fish of this size. It didn’t matter how tired or seasick I was, the data had to be collected. 

When I found out that I had been offered a field-based PhD extending my shark-deterrent research from my Honours, other than being over-the-moon, I knew I had a big few years ahead of me. I immediately began preparing mentally for the challenges that came along with my field-based research. Particularly the long periods of time I knew I would spend away from home and my family. 

Read the rest of this entry »




Many animals won’t cope with climate change without access to ample drinking water

12 08 2020

Climate change implies change in temperature and water, and both factors shape species’ tolerances to thermal stress. In our latest article, we show that lack of drinking water maximises differences in tolerance to high temperatures among populations of Iberian lizard species.

drinking

Climate change is a multidimensional phenomenon comprising temporal and spatial shifts in both temperature and precipitation (1). How we perceive climate change depends on whether we measure it as shift in (i) mean conditions (e.g., the mean air temperature or rainfall over a decade within a given territory), (ii) magnitude or frequency of extreme conditions (e.g., the frequency of floods or tornados or the number of days with temperatures or rainfall above or below a given threshold), or (iii) speed at which mean or extreme conditions change in space and/or time.

In aquatic ecosystems, climate change further alters water acidity, oxygen dissolution and melting of ice. However, many people, including some scientists, tend to equate climate change erroneously with increased mean temperatures. Psychologists have made the semantic point that the use of the expressions climate change and global warming as synonyms can give mixed messages to politicians, and society in general, about how serious and complex the climate emergency we are facing really is (2, 3) — see NASA’s simple-worded account on the subject here.

In our latest article (4), we reviewed the ecological literature to determine to what extent ecologists investigating the tolerance of terrestrial animals to high temperatures have looked at thermal effects over water effects. It turns out, they were five times more likely to examine temperature over water.

cb_BAAE_WaterLizardsNetwork

Frequency of correlations between climate (air temperature versus precipitation) and tolerance to high temperature of terrestrial fauna in 64 papers published in the ecological literature (thickest link = 36, thinnest link = 2) following a systematic literature review in Scopus (4).

This is counterintuitive. Just imagine you have been walking under the sun for several hours on one of those dog days of summer, and you are offered to choose between a sunshade or a bottle of water. I’d bet you’d choose the bottle of water.

Read the rest of this entry »





Amphibian conservation in a managed world

1 04 2020

FrogBlog2

Crinia parinsignifera (top) and Limnodynastes tasmaniensis (bottom). Photo: Kate Mason

The amphibian class is diverse, and ranges from worm-like caecilians to tiny frogs that live their entire lives within bromeliads high in the rainforest canopy. Regardless of form or habit, all share the dubious honour of being cited as the world’s most endangered vertebrate taxon, and 41% of the species assessed are threatened with extinction. Rapidly changing climates will further exacerbate this situation as amphibians are expected to be more strongly affected than other vertebrates like birds or mammals.

This peril stems from a physiological dependence on freshwater.

Amphibians breathe (in part) through their skin, so they maintain moist skin surfaces. This sliminess means that most amphibians quickly dry out in dry conditions. Additionally, most amphibian eggs and larvae are fully aquatic. One of the greatest risks to populations are pools that dry too quickly for larval development, which leads to complete reproductive failure.

This need for freshwater all too often places them in direct competition with humans.

To keep pace with population growth, humans have engineered a landscape where the location, and persistence of water is tightly controlled. In seeking water availability for farming and amenity, we all too often remove essential habitats for amphibians and other freshwater fauna.

To protect amphibians from decline and extinction, land managers may need to apply innovative techniques to support vulnerable species. With amphibians’ strong dependence on freshwater, this support can be delivered by intelligently manipulating where and when freshwater appears in the landscape, with an eye to maintaining habitats for breeding, movement and refuge. A range of innovative approaches have been attempted to date, but they are typically developed in isolation and their existence is known only to a cloistered few. A collation of the approaches and their successes (and failures) has not occurred.

In our latest paper, we used a systematic review to classify water-manipulation techniques and to evaluate the support for these approaches. Read the rest of this entry »





Did people or climate kill off the megafauna? Actually, it was both

10 12 2019

When freshwater dried up, so did many megafauna species.
Centre of Excellence for Australian Biodiversity and Heritage, Author provided

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

Earth is now firmly in the grips of its sixth “mass extinction event”, and it’s mainly our fault. But the modern era is definitely not the first time humans have been implicated in the extinction of a wide range of species.

In fact, starting about 60,000 years ago, many of the world’s largest animals disappeared forever. These “megafauna” were first lost in Sahul, the supercontinent formed by Australia and New Guinea during periods of low sea level.

The causes of these extinctions have been debated for decades. Possible culprits include climate change, hunting or habitat modification by the ancestors of Aboriginal people, or a combination of the two.


Read more: What is a ‘mass extinction’ and are we in one now?


The main way to investigate this question is to build timelines of major events: when species went extinct, when people arrived, and when the climate changed. This approach relies on using dated fossils from extinct species to estimate when they went extinct, and archaeological evidence to determine when people arrived.


Read more: An incredible journey: the first people to arrive in Australia came in large numbers, and on purpose


Comparing these timelines allows us to deduce the likely windows of coexistence between megafauna and people.

We can also compare this window of coexistence to long-term models of climate variation, to see whether the extinctions coincided with or shortly followed abrupt climate shifts.

Data drought

One problem with this approach is the scarcity of reliable data due to the extreme rarity of a dead animal being fossilised, and the low probability of archaeological evidence being preserved in Australia’s harsh conditions. Read the rest of this entry »





Environmental damage kills children

1 10 2019

Yes, childrenairpollutionit’s a provocative title, I agree. But then again, it’s true.

But I don’t just mean in the most obvious ways. We already have good data showing that lack of access to clean water and sanitation kills children (especially in developing nations), that air pollution is a nasty killer of young children in particular, and now even climate change is starting to take its toll.

These aspects of child health aren’t very controversial, but when we talk about the larger suite of indicators of environmental ‘damage’, such as deforestation rates, species extinctions, and the overall reduction of ecosystem services, the empirical links to human health, and to children in particular, are far rarer.

This is why I’m proud to report the publication today of a paper on which I and team of wonderful collaborators (Sally Otto, Zia Mehrabi, Alicia Annamalay, Sam Heft-Neal, Zach Wagner, and Peter Le Souëf) have worked for several years.

I won’t lie — the path to publishing this paper was long and hard, I think mainly because it traversed so many different disciplines. But we persevered and today published the paper entitled ‘Testing the socioeconomic and environmental determinants of better child-health outcomes in Africa: a cross-sectional study among nations* in the journal BMJ Open.

Read the rest of this entry »





How to fix a broken river

5 04 2019

murraycod

It seems that most of what I do these days is measure, model, or otherwise quantify environmental damage. While I dabble in restoration, occasionally I’m involved in a project that really can make a positive difference.

If you’re an Australian, you’ll know a thing or two about just how much of a clusterfuck our biggest river system has turned into. From mismanagement, to outright theft, to lobbyist-driven over-exploitation, to climate change itself, the Murray-Darling system is now in a right mess.

So, I’ll pretext this post with a caveat — no amount of ecological restoration can ‘fix’ a compromised river if there’s no water in it. Goes without saying, really.

But, if you do have water, then there are things one can do to promote populations of various creatures living in it, like fish.

Dubbed the ‘honeypot effect’ — we have just shown that providing woody habitat, or ‘snags’, for native fish in the Murray River increases population size. Read the rest of this entry »





South Australia doesn’t value its environment

5 09 2018

how we treat our environmentThe South Australian State Budget was released yesterday, and as has been the trend for the last ten years or so, the numbers are not good for the State’s environment.

While it has been reported that the budget includes the loss of 115 full-time staff from the Department of Environment and Water, the overall cuts run much deeper. They also herald a new era of not giving a tinker’s cuss for the sorry state of our environment.

I took the liberty of amassing the budget data with respect to environmental spending in this State since 2002-2003 (the earliest year I could find budget papers), and now I’ve just added the 2018-2019 data.

If I’ve selected the appropriate amounts, — side note: someone desperately needs to teach these budget bean-counters how to standardise, report, itemise, and organise data much, much better than they do (my first-year students could do a better job drunk and blindfolded) — then this is what environmental spending (including environment, biodiversity, water, and the Environment Protection Authority) has looked like since 2002: Read the rest of this entry »





Biodiversity is everyone’s responsibility

13 07 2018

Workspace: Team Of Diverse Workers Put Hands TogetherI’m not sure if many South Australians are aware of this, but the Parliamentary Inquiry into Biodiversity by the Environment, Resources and Development Committee presented a report to the 53rd Parliament of South Australia in March 2017. I thought it worthwhile reproducing their executive summary here on CB.com (I’ve highlighted the text that I deem to be rather insightful and simultaneously damning from our own elected government representatives):

This report summarises the findings and recommendations of the South Australian Parliament’s Environment, Resources and Development Committee’s inquiry into biodiversity in South Australia. Specifically, the inquiry investigated the regulatory and policy framework to determine whether it appropriately supports terrestrial and marine ecological processes, biodiversity values and abates species extinction.

The Committee found that in spite of the efforts of the State and Federal governments, industry and private landholders in South Australia, the condition of biodiversity in the State continues to decline. Species extinctions have occurred in the past and a further “extinction debt” still exists. There is no reason to believe that this trend will improve without a change to the way we approach biodiversity conservation.

A key theme to emerge from the Inquiry is that biodiversity conservation needs to be everyone’s responsibility; State and Federal government, industry, the broader community, and private landholders.

This also means that biodiversity conservation needs to occur across both public and private land, with actions coordinated at a landscape scale.

Making biodiversity conservation everyone’s responsibility requires a range of measures, including legislative reform, improved management of threats and greater involvement of the community. The provision of greater resources would yield faster results.

This report has focused on several key themes that emerged from submissions to the Inquiry.

Regulating for better biodiversity – South Australia’s legislative framework

South Australia’s current legislative framework does not provide for optimum biodiversity outcomes.

Three key issues contribute to this –

  • an out-of-date suite of environmental legislation that lacks cohesion and consistency, particularly regarding enforcement and compliance provisions;
  • inadequate and incomplete processes for identifying and protecting at-risk elements that need special measures (e.g. for protection of specific threatened species and ecological communities); and
  • inadequate consideration of biodiversity conservation in legislation that regulates human activities. In particular, there is a lack of cohesion between the environmental legislative and policy framework and land use planning, assessment and approval.
  • Statutory fragmentation of biodiversity considerations – that is, consideration of different aspects of biodiversity under different pieces of legislation – results in lack of cohesion and consistency, duplication and inefficiency, and makes it difficult to implement a landscape approach or to identify strategic opportunities and risks.

Taken as a whole, current enforcement provisions do not provide for effective and proportionate compliance action. Enforcement and compliance provisions across the relevant legislation are uneven in their approach. For example, penalties appear to be disproportionate and not risk-based (although there are some exceptions). Modern enforcement tools such as compliance orders, civil remedies and alternative penalties (such as administrative penalties, payment of damages including exemplary damages, remediation orders etc) are not included in all relevant legislation. There is some duplication in offences and inconsistency in the types of sanctions and penalty ranges.

There is an urgent need to amend the legislative framework to support any attempt to improve biodiversity outcomes.

The best approach will be based on clear, shared responsibility for biodiversity outcomes, supported by individual accountability. However, such a change will require policy development and drive.

To ensure forward momentum and improvements in the short term while developing the policy settings to support such a step-change, a staged approach could be implemented. There are various ways this could be achieved.

The Committee suggests a 3-stage approach to reforming the legislative framework. The Committee recommends the creation of a Biodiversity Expert Panel that is responsible for advancing this 3-stage approach.

  1. The first stage will involve amendments to improve operation and effectiveness of the regulatory regime within current policy settings, acknowledging that as a result of Stage 3, provisions may be altered or moved into different pieces of legislation. Amendments generally would be to the existing ‘environmental’ Acts, and primarily to the National Parks and Wildlife Act 1972 and Native Vegetation Act 1991. They would include many of the specific areas for amendment identified in EDO submissions (2011 & 2015) as well as in the SA Government submission, for example, beginning with amendments to improve current environmental legislation.
  2. Stage 2 would progress to amendments to improve integration between Acts and improve support for landholders and community participation.
  3. Stage 3 would implement a system whereby all resource use and management would be managed by one piece of legislation, with protection of biodiversity and sustainable development at its core. Provisions for protected area management, and for the scientific work involved in identifying threatened species and communities, may be contained in separate legislation.

Threats, ecological resilience and restoration

The State’s native biodiversity is facing myriad of current threats, including habitat loss and fragmentation (due to development and changing land-use), pest plants and animals, and control burn regimes. There is a need for more stringent vegetation protection, better informed and enacted control and management strategies of known pest plants and animals, and a revision of burning regimes.

Future threats to the State’s biodiversity will be largely driven by climate change impacts and the interaction with existing major threats (e.g. urbanisation and changing land use). Adequately preparing for and managing such future threats will require knowledge of projected changes and pro-active preparation for such changes.

Working with the community

Involvement of the community is an essential part of any biodiversity conservation strategy for the State. It is a foundation stone for moving to a point where biodiversity conservation is everyone’s business.

Community engagement will become increasingly important for biodiversity conservation, especially given the growing role of volunteers to support works on public land as well as the voluntary conservation efforts of private landholders. The expanding role of volunteers reenforces that biodiversity conservation is everyone’s business.

South Australia’s approach to biodiversity conversation on private land needs to be reinvigorated.

Cross cutting themes

There were several cross cutting themes identified in submissions to the Inquiry. There was broad recognition of the strong cultural and historic significance of elements of biodiversity to Aboriginal people, and that this is often poorly understood outside those communities. Continuing to identify ways for Aboriginal people to contribute to land and water management in South Australia remains a priority.

With respect to knowledge generation, critical knowledge gaps exist that need to be filled and existing knowledge is not being adequately understood, communicated or applied. From a resourcing perspective, there is concern that insufficient funds are being allocated to biodiversity conservation, which is affecting work on public and private lands.

The management of over-abundant species in South Australia remains a challenge, noting the recent impacts of long-nose fur seals in the Lower Lakes and Coorong, and ongoing concerns regarding the impact of animals such as little corellas and some species of kangaroos on negative vegetation.

 





Not 100% renewable, but 0% carbon

5 04 2017

635906686103388841-366754148_perfection1Anyone familiar with this blog and our work on energy issues will not be surprised by my sincere support of nuclear power as the only realistic solution to climate change in the electricity (and possibly transport and industrial heat) arena. I’ve laid my cards on the table in the peer-reviewed literature (e.g., see here, here, here, here, here & here) and the standard media, and I’ve even joined the board of a new environmental NGO that supports nuclear.

And there is hope, despite the ever-increasing human population, rising consumerism, dwindling resources, and the ubiquity of ideologically driven and ethically compromised politicians. I am hopeful for several reasons, including rising safety and reliability standards of modern nuclear technology, the continued momentum of building new fission reactors in many countries, and even the beginnings of real conversations about nuclear power (or at least, the first steps toward this) in countries where nuclear energy is currently banned (e.g., Australia). I’m also heartened by the fact that nearly every conservation scientists with whom I speak is generally supportive, or at least non-resistant, to the idea of nuclear power as part of the climate change solution. An open letter by our colleagues attests to this. In fact, every day that passes brings new evidence that we cannot ignore this solution any longer.

Even despite the evidence in support of implementing a strong nuclear component into climate change-mitigation strategies, one of the most frequent arguments for not doing so is that society can achieve all of its energy needs and simultaneously combat climate change by constructing 100% renewable-energy pathways. While it is an easy mantra to repeat because it feels right intrinsically to nearly everyone with an environmental conscience, as a scientist I also had to ask if such a monumental task is even technically feasible. Read the rest of this entry »





Not all wetlands are created equal

13 02 2017

little-guyLast year I wrote what has become a highly viewed post here at ConservationBytes.com about the plight of the world’s freshwater biodiversity. In a word, it’s ‘buggered’.

But there are steps we can take to avoid losing even more of that precious freshwater biodiversity. The first, of course, is to stop sucking all the water out of our streams and wetlands. With a global population of 7.5 billion people and climbing, the competition for freshwater will usually mean that non-human life forms lose that race. However, the more people (and those making the decisions, in particular) realise that intact wetlands do us more good as wetlands rather than carparks, housing developments, or farmland (via freshwater filtering, species protection, carbon storage, etc.), the more we have a chance to save them.

My former MSc student, the very clever David Deane1, has been working tirelessly to examine different scenarios of wetland plant biodiversity change in South Australia, and is now the proud lead author of a corker of a new paper in Biological Conservation. Having already published one paper about how wetland plant biodiversity patterns are driven by rare terrestrial plants, his latest is a very important contribution about how to manage our precious wetlands. Read the rest of this entry »





Battling the seven-headed hydra: Crassula control in Europe

8 11 2016

Hydra. Seba Albertus (1734-1765). Image from Wellsome Trust

Hydra. Seba Albertus (1734-1765). Image from Wellsome Trust

A contribution by Claire Wordley of Conservation Evidence.

The Australian swamp stonecrop (Crassula helmsii) is a small, unassuming looking plant with incredible resilience. It can survive both baking heat and freezing cold; it can live underwater, on the water’s surface and on land; it can survive being dried out, bleached and sprayed with hot foam; and it can regenerate from tiny fragments. Unfortunately, in the UK and elsewhere in Europe it is an invasive species, choking the oxygen from ponds and shading out other plants with knock-on effects for entire freshwater ecosystems.

Swamp stonecrop, also known as New Zealand pigmyweed, was first introduced to the UK from Tasmania in 1911 and sold in garden centres from 1927 as an ornamental pond oxygenator. Shockingly, despite being documented as an invasive plant in New Forest ponds as early as 1976, its sale in the UK was only banned in 2014. Crassula appears to be spread mostly by people, whether deliberately or accidentally; it appears to be concentrated around car parks, residential areas and areas where equipment such as fishing gear is likely to have come from an infected site. Nearly 20% of 700 UK waterbodies surveyed contained the weed. Since every 10% increase in Crassula corresponds to a 5% decrease in native vegetation, and negative effects of Crassula invasion have been documented for zooplankton, macro-invertebrates and fish, with possible negative impacts on amphibians as well, control and ideally eradication is clearly needed. But what works to destroy this superweed?

Killing the hydra

Crassula helmsii (photo by Benjamin Blondel)

Crassula helmsii (photo by Benjamin Blondel)

Like the seven-headed hydra of legend, Crassula helmsii seems able to regenerate after even harsh treatment and being shattered into tiny pieces. Documenting clearly what works to control this beast – and what does not – is critical. This work has recently been completed by Conservation Evidence at the University of Cambridge, as part of an ongoing series on controlling freshwater invasives. The team has worked to collect all the evidence on different ways of killing Crassula, and experts have scored these for their effectiveness (or otherwise).

One of the most effective ways to knock back Crassula appears to be applying herbicides, particularly glyphosate and diquat or diquat alginate. While each of these performed well to reduce Crassula in many trials – and the use of glyphosate and diquat together led to a 98% reduction in one trial – there are concerns that while the medicine could cure the disease, it could kill the patient. One study in the New Forest noted that native plant cover fell in the treatment sites at a greater rate than in the control sites, and glyphosate appears to be toxic to amphibians. There might also be adverse effects on some bird species, although this could be due more to habitat-level changes than direct toxicity, because other birds appeared to benefit from wetlands being sprayed with glyphosate. Read the rest of this entry »





World’s greatest conservation tragedy you’ve probably never heard of

13 10 2016

oshiwara_riverI admit that I might be stepping out on a bit of a dodgy limb by claiming ‘greatest’ in the title. That’s a big call, and possibly a rather subjective one at that. Regardless, I think it is one of the great conservation tragedies of the Anthropocene, and few people outside of a very specific discipline of conservation ecology seem to be talking about it.

I’m referring to freshwater biodiversity.

I’m no freshwater biodiversity specialist, but I have dabbled from time to time, and my recent readings all suggest that a major crisis is unfolding just beneath our noses. Unfortunately, most people don’t seem to give a rat’s shit about it.

Sure, we can get people riled by rhino and elephant poaching, trophy hunting, coral reefs dying and tropical deforestation, but few really seem to appreciate that the stakes are arguably higher in most freshwater systems. Read the rest of this entry »





More things stay the same, more we retrogress

20 07 2016

obrazek_1idiommmmsmmWithin six months of Abbott and the Coalition seizing power in the 2013 Australian election, decades—if not centuries—of environmental damage and retrograde policies unfolded. But this was no run-of-the-mill incompetence and neglect by government—this was an all-out attack on anything with the merest whiff of environmental protection. The travesty is well-documented, from infamously axing both the carbon-pricing scheme and climate commission, eradicating Labor’s 80% emissions-reduction target by 2050, diluting the Renewable Energy Target, refusing to commit to enforcing the Illegal Logging Prohibition Act (fortunately, this is now law), defunding the only independent legal entity available to limit environmentally destructive development (Environmental Defenders Office), to even attempting to remove the rights of environmental groups to challenge development proposals (thankfully, that failed).

The Coalition’s backward and ineffectual climate change-mitigation policies alone are evidence enough for long-term damage, but their war on the environment in general means that even the future election of a more environmentally responsible government will not undo the damage quickly, if at all. As a result of these and other nearsighted policies, Australia remains one of the highest per-capita greenhouse-gas emitters on the planet, has one of the highest per-capita water uses of any nation, leads the world in mammal extinctions, continues to deforest its already forest-poor landscape, and is a society utterly unprepared to deal with the future challenges of a degraded planet.
Read the rest of this entry »





Australia pisses away the little water it has

9 05 2016

cow_drinking_australia_dryWater, water nowhere, with little left to drink.

Australians are superlative natural resource wasters, but living in the driest inhabited continent on the planet, you’d think we’d be precious about our water use.

You’d be wrong.

On the contrary, Australia has a huge water footprint (defined as “the total volume of freshwater that is used to produce the goods and services consumed by the people of the nation”). For internal domestic use (i.e., not including agricultural and industrial uses, or water imported directly or within other goods), Australians use about 341000 litres per person per year (data from 1997–2001), which is six times the global average of 57000 litres per person per year (1).

Agricultural production is one of the chief consumers of freshwater around the world. For example, the global average virtual water content of rice (paddy) is 2.29 million litres/tonne produced, and for wheat it is 1.33 litres/tonne. Growing crops for biofuel in particular has a huge water footprint — depending on the crop in question, it takes an average of 1400–20000 litres of water to produce just one litre of biofuel (2). If an agricultural product comes from livestock — say, meat, leather, or wool — the water content is typically much higher because of the feed required to keep the animal alive. For example, it takes about three years to raise beef cattle to slaughtering age, with an average of 200 kg of boneless beef produced per animal. This requires about 1,300 kg of grains, 7200 kg of pasture or hay, and 31000 litres of water for drinking and cleaning. This means that the total amount of water required to produce 1 kg of beef is about 15340 litres (1). For Australia, which has over 20 million or so cattle at any one moment, the water footprint alone should at least be cause for concern the next time you tuck into a steak dinner. Read the rest of this entry »





Biowealth

24 02 2016

frogWhile I’ve blogged about this before in general terms (here and here), I thought it wise to reproduce the (open-access) chapter of the same name published in late 2013 in the unfortunately rather obscure book The Curious Country produced by the Office of the Chief Scientist of Australia. I think it deserves a little more limelight.

As I stepped off the helicopter’s pontoon and into the swamp’s chest-deep, tepid and opaque water, I experienced for the first time what it must feel like to be some other life form’s dinner. As the helicopter flittered away, the last vestiges of that protective blanket of human technological innovation flew away with it.

Two other similarly susceptible, hairless, clawless and fangless Homo sapiens and I were now in the middle of one of the Northern Territory’s largest swamps at the height of the crocodile-nesting season. We were there to collect crocodile eggs for a local crocodile farm that, ironically, has assisted the amazing recovery of the species since its near-extinction in the 1960s. Removing the commercial incentive to hunt wild crocodiles by flooding the international market with scar-free, farmed skins gave the dwindling population a chance to recover.

redwoodConservation scientists like me rejoice at these rare recoveries, while many of our fellow humans ponder why we want to encourage the proliferation of animals that can easily kill and eat us. The problem is, once people put a value on a species, it is usually consigned to one of two states. It either flourishes as do domestic crops, dogs, cats and livestock, or dwindles towards or to extinction. Consider bison, passenger pigeons, crocodiles and caviar sturgeon.

As a conservation scientist, it’s my job not only to document these declines, but to find ways to prevent them. Through careful measurement and experiments, we provide evidence to support smart policy decisions on land and in the sea. We advise on the best way to protect species in reserves, inform hunters and fishers on how to avoid over-harvesting, and demonstrate the ways in which humans benefit from maintaining healthy ecosystems. Read the rest of this entry »





Australians: out-of-touch, urban squanderers

23 03 2015

There’s a romantic myth surrounding Australia that is pervasive both overseas and within the national psyche: this sun-scorched continent home to stoic bushmen1 that eek out a frugal, yet satisfying existence in this harsh rural land. Unfortunately that ideal is anathema to almost every Australian alive today.

While some elements of that myth do have a basis in reality – it is indeed a hot, dry, mostly inhospitable place if you count the entire land area (all 7.69 million square kilometres of it), and it does have the dubious honour of being the driest inhabited continent on Earth – most Australians live nowhere near the dry interior or the bush.

Despite our remarkably low average population density (a mere 3.09 people per square kilometre), Australia is in fact one of the most urbanised nations on the planet, with nearly 90% of its citizenry living within a major urban centre. As a result, our largely urban/suburban, latte-sipping, supermarket-shopping population has little, if any, connection to the vast landscape that surrounds its comfortable, built-up environs. There should be little wonder then that Australians are so disconnected from their own ecology, and little surprise that our elected officials (who, after all, represent the values of the majority of the citizens they purport to represent), are doing nothing to slow the rapid flushing of our environment down the toilet. Indeed, the current government is in fact actively encouraging the pace of that destruction. Read the rest of this entry »








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