Blind shrimps, translucent snails: the 11 mysterious new species we found in potential fracking sites



An ostracod, a small crustacean with more than 70,000 identified species.
Anna33/Wikimedia, CC BY-SA

Jenny Davis, Charles Darwin University; Daryl Nielsen, CSIRO; Gavin Rees, CSIRO, and Stefanie Oberprieler, Charles Darwin University

There aren’t many parts of the world where you can discover a completely new assemblage of living creatures. But after sampling underground water in a remote, arid region of northern Australia, we discovered at least 11, and probably more, new species of stygofauna.

Stygofauna are invertebrates that have evolved exclusively in underground water. A life in complete darkness means these animals are often blind, beautifully translucent and often extremely localised – rarely living anywhere else but the patch they’re found in.

The species we discovered live in a region earmarked for fracking by the Northern Territory and federal government. As with any mining activity, it’s important future gas extraction doesn’t harm groundwater habitats or the water that sustains them.

Our findings, published today, show the importance of conducting comprehensive environmental assessments before extraction projects begin. These assessments are especially critical in Australia’s north, where many plants and animals living in surface and groundwater have not yet been documented.

When the going gets tough, go underground

Stygofauna were first discovered in Western Australia in 1991. Since then, these underground, aquatic organisms have been recorded across the continent. Today, more than 400 Australian species have been formally recognised by scientists.

The subterranean fauna we collected from NT aquifers, including a range of species unknown to science. A–C: Atyid shrimps, including Parisia unguis; D-F: Amphipods in Melitidae family; G: The syncarid species Brevisomabathynella sp.; H-J: members of the Candonidae family of ostracods; K: the harpacticoid species Nitokra lacustris; L: a new species of snail in the Caenogastropoda: M-N: Members of the Cyclopidae family of copepods; O: The worm species Aeolosoma sp.
GISERA, Author provided

Stygofauna are the ultimate climate change refugees. They would have inhabited surface water when inland Australia was much wetter. But as the continent started drying around 14 million years ago, they moved underground to the relatively stable environmental conditions of subterranean aquifers.




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Today, stygofauna help maintain the integrity of groundwater food webs. They mostly graze on fungal and microbial films created by organic material leaching from the surface.

In 2018, the final report of an independent inquiry called for a critical knowledge gap regarding groundwater to be filled, to ensure fracking could be done safely in the Northern Territory. We wanted to determine where stygofauna and microbial assemblages occurred, and in what numbers.

Our project started in 2019, when we carried out a pilot survey of groundwater wells (bores) in the Beetaloo Sub-basin and Roper River region. The Beetaloo Sub-basin is potentially one of the most important areas for shale gas in Australia.

What we found

The stygofauna we found range in size from centimetres to millimetres and include:

  • two new species of ostracod: small crustaceans enclosed within mussel-like shells

  • a new species of amphipod: this crustacean acts as a natural vacuum cleaner, feeding on decomposing material

  • multiple new species of copepods: tiny crustaceans which form a major component of the zooplankton in marine and freshwater systems

  • a new syncarid: another crustacean entirely restricted to groundwater habitats

  • a new snail and a new worm.

A thriving stygofauna ecosystem lies beneath the surface of northern Australia’s arid outback. We sampled water through bores to measure their presence.
Jenny Davis, Author provided

These species were living in groundwater 400 to 900 kilometres south of Darwin. We found them mostly in limestone karst habitats, which contain many channels and underground caverns.

Perhaps most exciting, we also found a relatively large, colourless, blind shrimp (Parisia unguis) previously known only from the Cutta Cutta caves near Katherine. This shrimp is an “apex” predator, feeding on other stygofauna — a rare find for these kinds of ecosystems.

A microscopic image of Parisia unguis, a freshwater shrimp.
Stefanie Oberprieler, Author provided

Protecting groundwater and the animals that live there

The Beetaloo Sub-basin in located beneath a major freshwater resource, the Cambrian Limestone Aquifer. It supplies water for domestic use, cattle stations and horticulture.

Surface water in this dry region is scarce, and it’s important natural gas development does not harm groundwater.

The stygofauna we found are not the first to potentially be affected by a resource project. Stygofauna have also been found at the Yeelirrie uranium mine in Western Australia, approved by the federal government in 2019. More research will be required to understand risks to the stygofauna we found at the NT site.




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It’s not worth wiping out a species for the Yeelirrie uranium mine


The discovery of these new NT species has implications for all extractive industries affecting groundwater. It shows the importance of thorough assessment and monitoring before work begins, to ensure damage to groundwater and associated ecosystems is detected and mitigated.

Gas infrastructure at Beetaloo Basin
The Beetaloo Basin is part of the federal government’s gas expansion strategy.
Department of Industry, Science, Energy and Resources

Where to from here

Groundwater is vital to inland Australia. Underground ecosystems must be protected – and not considered “out of sight, out of mind”.

Our study provides the direction to reduce risks to stygofauna, ensuring their ecosystems and groundwater quality is maintained.

Comprehensive environmental surveys are needed to properly document the distribution of these underground assemblages. The new stygofauna we found must also be formally recognised as a new species in science, and their DNA sequence established to support monitoring programs.

Different species of copepods from various parts of the world.
Andrei Savitsky/Wikimedia, CC BY-SA

Many new tools and approaches are available to support environmental assessment, monitoring and management of resource extraction projects. These include remote sensing and molecular analyses.

Deploying the necessary tools and methods will help ensure development in northern Australia is sustainable. It will also inform efforts to protect groundwater habitats and stygofauna across the continent.




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The Conversation


Jenny Davis, Professor, Research Institute for Environment & Livelihoods, Charles Darwin University, Charles Darwin University; Daryl Nielsen, Principal Research Scientist, CSIRO; Gavin Rees, Principal Research Scientist, CSIRO, and Stefanie Oberprieler, Research associate, Charles Darwin University

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

It’s not worth wiping out a species for the Yeelirrie uranium mine


File 20190426 61877 ax136m.jpg?ixlib=rb 1.1
The Western Australian outback may look bare at first glance, but it’s teeming with wildlife, often beneath the surface.
Shutterstock

Gavin Mudd, RMIT University

One day before calling the election, the government approved the controversial Yeelirrie uranium mine in the remote wilderness of Western Australia, about 500km north of Kalgoorlie.

The Tjiwarl Traditional Owners have fought any uranium mining on their land for the last 40 years, and the decision by the government wasn’t made public until the day before Anzac Day.

This region is home to several of Australia’s deposits of uranium and not only holds cultural significance as part of the Seven Sisters Dreaming Songline, but also environmental significance.




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If the mine goes ahead, groundwater levels would drop by 50cm and wouldn’t fully recover for 200 years. And 2,422 hectares of native vegetation would be cleared.

I visited the site 16 years ago and, like the rest of the Western Australian outback, there’s a wonderful paradox where the land appears barren, but is, in fact, rich with biodiversity.

The former pilot open cut at Yeelirrie, February 2003 – unrehabilitated from the early 1980s.
Photo G M Mudd

Native animals living in underground water, called stygofauna, are one such example of remarkable Australian fauna that aren’t obvious at first glance. These animals are under threat of extinction if the Yeelirrie uranium mine goes ahead.

Stygofauna are ecologically fragile

Most stygofauna are very tiny invertebrates, making up species of crustaceans, worms, snails and diving beetles. Some species are well adapted to underground life – they are typically blind, pale white and with long appendages to help them find their way in total darkness.

Yeelirrie stygofauna.
Photograph by Giulia Perina, Subterranean Ecology Pty Ltd

In 2016, the Western Australian Environmental Protection Agency (EPA) advised against building the Yeelirrie uranium mine because it would threaten the stygofauna species there, despite the proposed management strategies of Cameco Australia, the mine owner.

Stygofauna are extremely local, having evolved in the site they’re found in. This means individual species aren’t found anywhere else in the world.

EPA chairman Tom Hatton said:

Despite the proponent’s well-considered management strategies, based on current scientific understanding, the EPA concluded that there was too great a chance of a loss of species that are restricted to the impact area.

Yeelirrie has a rich stygofauna habitat, with 73 difference species recorded.

A species of stygofauna in Yeelirrie.
Photograph by Giulia Perina, Subterranean Ecology Pty Ltd

And to get to the uranium deposit, the miners need to dig through the groundwater, a little like pulling the plug in the middle of the bathtub. Stygofauna have adapted to living at different levels of the water, so pulling out the plug could dry out important parts of their habitat.

Stygofauna are also susceptible to any changes in the chemistry of the groundwater. We simply do not know with confidence what mining will do to the groundwater chemistry at Yeelirrie in the long term. Various wastes will be backfilled into former pits, causing uncertainty for the welfare of surrounding stygofauna.




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The approval conditions suggest that the mine should not be allowed to cause extinction – but if this does happen, nothing can be done to reverse it. And there would be no penalty to Cameco either – which has said it can’t guarantee such a condition can be met.

So are the economic benefits worth wiping out a species?

Short answer: no. But let’s, for a moment, ignore these subterranean animals and look at whether the mine would be beneficial.

Yeelirrie is one of Australia’s largest uranium deposits – and yet it has a low grade of 0.15% (as uranium oxide). This refers to the amount of uranium found in rock. For comparison, the average grade of uranium mines globally is normally 0.1 to 0.4% of uranium oxide (with some higher and others lower).

And Cameco’s Cigar Lake and McArthur River mines in Canada have typically been 15-20% of uranium oxide. Despite such rich ore, McArthur River was uneconomic and closed indefinitely in early 2018.

What’s more, the future of nuclear power is not bright. According to the World Nuclear Industry Status Report, the number of nuclear reactors under construction around the world is at its lowest point in a decade, as renewable energy increases. The amount of nuclear electricity produced each year is flat. And nuclear’s share of global electricity is constantly falling behind renewables.




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But, in any case, we don’t yet know enough about these stygofauna to warrant their extinction. They could, for instance, have untold benefits to medical science, or perhaps have wider environmental and cultural significance.

And, ethically, what right do we have to wipe out a species? They have evolved and survived just like us. At the end of the day, there are much safer, cheaper, more ethical and cleaner ways to generate electricity to boil a kettle.The Conversation

Gavin Mudd, Associate Professor of Environmental Engineering, RMIT University

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