waterways/wetlands – Page 21

Sub-zero heroes: extremophiles call salty Antarctic lakes home

Oct 012013

Original story by Rick Cavicchioli at the Conversation

Imagine a lake so salty its water exists in a liquid state at -20 °C – then picture something thriving in that seemingly lethal environment.

Even with water temperatures down to -20°C, Deep Lake is home to a surprising amount of life (and not just our research camp). Photo: Rick Cavicchioli

Such an organism exists; several of them, in fact. In a paper published in the Proceedings of the National Academy of Sciences today, along with colleagues from UNSW and the US, I describe those microbes – dubbed “extremophiles” – which live in the hostile depths of an Antarctic lake.

As their name suggests, extremophiles are organisms that thrive in environments deadly to other living things. Examples include radioresistant extremophiles which need nuclear waste to survive; some (thermoacidophiles) prefer to reside in near-boiling acidic water.

The colours of the Grand Prismatic Spring in Yellowstone National Park are the result of pigmented extremophile bacteria.Photo: Achint Thomas

Still others call the saltiest and least life-producing lake in the world – Deep Lake in Antarctica – their home.

Located around 5km from Davis Station, Deep Lake was formed about 3,500 years ago when the Antarctic continent rose, isolating a section of ocean. The water in the 36m deep lake is now so salty it remains in liquid form down to –20 °C and, unsurprisingly, almost nothing is able to grow in it.

What does grow, though, is fascinating.

We took water samples from the lake at depths of five, 13, 24 and 36 metres. We studied the entire genetic sequence, or genome, of the microbes living there, to work out how they had evolved to cope with the extremely harsh conditions.

The halophilic (Greek for “salt-loving”) extremophiles in Deep Lake belong to a group of microbes called haloarchaea. Due to much higher rates of gene-swapping – or promiscuity – than normally observed in the natural world, many species in Deep Lake are able to benefit from the genes of others.

What is also remarkable is that in addition to all the promiscuous gene swapping, the dominant members of the community retain their own identity as a species, and coexist with others, exploiting different niches without impinging on each other.

Some microbes consume proteins in the water. Others consume sugars like glycerol, a by-product of algae living in the upper waters of the lake. The most prolific extremophile we found in Deep Lake – tADL – was one of the latter, comprising about 44% of the total cell community.

Deep Lake, Antarctica – home of halophilic microorganisms. Photo: Mark Milnes

Industry and astrobiology

It is estimated the haloarchaea grow very slowly in the lake, with only about six generations produced a year.

Enzymes from cold-adapted microbes could have significant industrial value. Their high activity in cold temperatures could provide reduced energy costs for processes that would otherwise require heating (such as cleaning) or which must be carried out at cold temperatures (such as food production or removing pollutants from cold, contaminated sites).

Those enzymes will be especially useful for transforming contaminated sites with particularly high levels of petroleum-based products.

Haloarchaea cells. Photo: NASA

Our findings that the haloarchaea in Deep Lake have the remarkable ability to grow under such cold and salty conditions provide thought-provoking insight for astrobiology studies – perhaps extraterrestrial life will exist in salty veins within ice present on planets and moons within our solar system (such as Jupiter’s icy moon Europa).

As a means of searching for extraterrestrial life, the enzymes from these cold-adapted haloarchaea may also be valuable for use in biosensors to assess whether biological reactions are taking place on other worlds.

Microbe cycles

In October this year, we will set off again for our third Antarctic expedition – this one lasting more than 12 months.

Building on knowledge gained from previous expeditions (one which lasted six weeks in 2006 and another of three months in 2008), the purpose of this trip is to monitor ecosystem stability in model marine-derived Antarctic lake and near-shore systems; in essence, addressing the question of what microorganisms do season by season, year after year in the frigid Antarctic wilderness.

Taking water samples from the middle of Deep Lake, December 2008. The boat was tethered to shore by a kilometre length of rope.

Our aim is to determine how microbial communities change throughout a complete annual cycle in three climate-sensitive Antarctic lakes – Ace Lake, Organic Lake and Deep Lake – and in a near-shore marine location.

Our group’s research to date reveals that Antarctic microbial communities are very delicate, with indications that environmental perturbation, including climate change, may prevent such communities from recovering, thereby altering the lake biogeochemistry forever.

Establishing what the microorganisms do in different seasons will reveal which microbial processes change, and how environmental perturbation will impact on normal ecological cycles in the Antarctic.

This essential evidence-based knowledge will form the underpinnings for evaluating the effects of climate change on sensitive ecosystems in the Antarctic.

Rick Cavicchioli receives funding from the Australian Research Council, Australian Antarctic Division and Australian Antarctic Science Program.

This article was originally published at The Conversation.
Read the original article.

Building a Raingarden

waterways/wetlands

Sep 302013

News release from Healthy Waterways

In June this year, Healthy Waterways and Bulimba Creek Catchment Coordinating Committee hosted a workshop on How to Build a Raingarden. Raingardens (also known as bioretention systems) are garden beds that use native plants and soil to capture, filter and treat stormwater runoff. A raingarden was constructed to treat stormwater from the new office at the Bulimba Creek Sustainability Centre. The process was captured on film.

For more information on how to build a raingarden, download the Healthy Waterways fact sheet.

Chambers to help fish turbine defence

Australian native freshwater species, waterways/wetlands

Sep 252013

Original story at Business Spectator

Australia's native fish could stand a better chance of survival when passing through hydropower turbines in major waterways thanks to an innovative mechanical chamber developed at UNSW.

A 17 day old Murray Cod showing evidence of injury (bubble in gut) resulting from rapid pressure changes.

When native fish migrate downstream they often pass through hydropower turbines and weirs. If they evade impact with the blades, fish can still suffer injury and even death due to extreme and rapid pressure changes when they go from deepwater upstream to shallower waters.

These pressure injuries, which include expanded swim bladders, are similar to the expansion injuries scuba divers might experience when surfacing too quickly. They are known as “barotrauma”.

“The pressure change these fish experience is like going from 10 metres below the water to the height of Mount Everest in about half a second,” says Mr Brett Miller, principal engineer and inventor from the UNSW Water Research Laboratory.

Miller and the team at the Water Research Laboratory have developed a pair of custom hydraulic “barochambers” that can simulate these rapid pressure changes. These will measure the decompression limit that fish can safely endure and guide the design of more environmentally and fish friendly water infrastructure.

Mini hydropower generators throughout the Murray Darling provide renewable energy to regional communities, but Miller says more research is needed on the potential risk of these generators on native fish populations.

“Fish welfare at river infrastructure is a problem in Australia and globally,” says Miller. “Safe passage needs to be considered at the construction and approval phases of hydropower infrastructure, and not as an afterthought.”

“This system allows us to measure fish mortality and injury against decompression rates,” he says.

Researchers at the NSW Department of Primary Industries Fisheries are currently using the mobile chambers, which feature a large glass window to observe the fish and an easy-to-use operating system that doesn’t require specialist knowledge.

The invention was a finalist for a 2013 Engineers Australia Excellence Award for innovation.

The project was co-funded by the NSW Office of Environment and Heritage, the NSW Department of Primary Industries (Fisheries) and the Australian Centre for Renewable Energy’s Emerging Renewables Program. This funding was administered through grants to Waratah Power.

A fast fish with a huge impact

pest species, waterways/wetlands

Sep 242013

Research news from Technische Universitaet Muenchen.

River banks are often reinforced to facilitate shipping. These reinforcements also protect fish against the waves from passing ships, thus creating the perfect conditions for invasive species. Photo: J. Brandner/TUM

Major changes to the Danube ecosystem

Globalization is breaking down barriers – also for plants and animals on the lookout for new homes. Rivers are also changing, in particular through the introduction of non-native species, often brought in by passing ships. In the Danube River, scientists have been observing a fish species conquering a new habitat and creating a totally new ecosystem in the process.

Recent decades have seen massive changes to many river systems. To improve passage for ships, humans have been straightening, deepening, and reinforcing river banks and altered the natural flow regime. Water temperatures are also rising as a result of climate change. All of which provides perfect conditions for the round goby, a fish traditionally found in the lower stretches of the Danube and along the coasts of the Black Sea. Today, however, round goby has expanded its distribution range significantly and can now be found in the headwater of the Danube as well as in the Rhine, the Baltic Sea and the Laurentian Great Lakes in North America.

Scientists at the Technische Universität München (TUM) have teamed up with the Bavarian State Collection of Zoology (ZSM) to investigate the strategies the round goby uses to conquer new stretches of river and the impact on the ecosystem and existing food webs. This is the first comprehensive study of this nature has been carried out.

The round goby is conquering new habitats in the upper Danube. Photo: J. Brandner/TUM

Colonization of the upper Danube

The scientists carried out their investigations in the Danube River. “Round goby reached the headwaters of the Danube only a few years ago. Probably as a stowaway in the ballast water of ships,” explains Jörg Brandner from the Chair of Aquatic Systems Biology. Since then, the fish has firmly established itself in the Bavarian Danube in an area stretching from the state border to the city of Regensburg.

In fall 2009, round goby reached the river stretch near the town of Bad Abbach and rapidly established a stable population. From here, individual fish moved further upstream. “In fall 2010 – just one year later – we found the first gobies in the river at Kelheim – around fifteen kilometers further upstream,” continues Brandner. “We did not expect the invasion to progress so rapidly.”

Jörg Brandner reads sensors that measure water temperature over time. Photo: A. Cerwenka/TUM

Native species in decline

The pioneers are particularly strong and powerful goby individuals, able to consume a broad range of foods and thus can outperform other species in the competition for food. They gradually eliminate native fish species such as the barbel and European chub and already account for over 70 percent of the entire fish population in some areas of their preferred habitat (rip-rap banks).

The round goby is also reducing the diversity and abundance of invertebrates. Stoneflies, caddisflies and mayflies are particularly hard hit as they become the invaders’ preferred prey in their new habitat. “The round goby quickly adapts to new surroundings, for example by changing its feeding habits,” says Prof. Jürgen Geist from the Chair of Aquatic Systems Biology. “That’s what makes this species so successful.”

Exportable ecosystem

The round goby is not the only fish advancing upstream from the Black Sea. There are currently five different goby species from the lower Danube making their way up the river. And the fish are not the first new settlers. They have already been preceded by many exotic snails, mussels and freshwater amphipods, some even hailing from other continents, e.g. Asia. Like the gobies, a number of these animals dominate native species now.

“Round gobies that reach a certain body size feed on mollusks and freshwater amphipods. Native species are often easier prey as they have not developed defense strategies against the newcomers. And this benefits the non-native species,” explains Geist.

The goby invasion has led to a ‘novel ecosystem’ in the headwater of the Danube comprising previously unknown combinations of species. This is not unique to the Danube, however. There are similar developments in the Rhine and in the Great Lakes of North America. “What we are observing is a very flexible and robust network of different species that adapts itself perfectly to new environments,” says Geist. However, the consequences are serious, he adds: “Biodiversity is declining and once the original ecosystem is lost, we can never go back.”

Publication:
Bigger is better: Characteristics of round gobies forming an invasion front in the Danube River, Joerg Brandner, Alexander F. Cerwenka, Ulrich K. Schliewen and Juergen Geist, PLOS ONE, dx.plos.org/10.1371/journal.pone.0073036

Contact:
Prof. Dr. Jürgen Geist
Technische Universität München
hair of Aquatic Systems Biology
T: +49 8161 71-3767
E: geist@tum.de
W: fisch.wzw.tum.de

Proposal to turn Swan Lake into a car park

community, government, waterways/wetlands, wildlife

Sep 242013

Original story by Brian Williams, the Courier Mail

BRISBANE City Council has raised doubts about the Port of Brisbane's controversial proposal to fill in a lake teeming with wildlife to build a car park.

The council has complained about how the port proposes to address the loss of biodiversity if the man-made wetland is bulldozed.

The Port of Brisbane's move to fill in a lake teeming with birds so it can be used as a car park for imported vehicles has been questioned by the city council. Photo: Tim Marsden, News Limited

Dubbed Swan Lake by birdwatchers, the wetland was built 14 years ago as open space and to handle run-off as the port expanded along the foreshore.

Despite intense development in the region, it has become heavily populated with birds and is one of the most important wetlands for black swans.

Cramped for space, the port now wants to fill in Swan Lake to make way for 20,000 to 30,000 imported cars which are parked at the port.

Queensland Conservation chairman Simon Baltais said if the Government approved the development it would set a precedent in which all environmental offsets offered by industry as a trade-off to land clearing would become worthless.

"They promise you something one day, then take it away the next,'' Mr Baltais said.

This would produce an impossible situation where all sorts of projects including major mines and ports for which environmental offsets were proposed would become worthless.

"Communities put a lot of trust in industry when they offer environmental offsets,'' he said.

"Communities oppose developments but are told if they let a development go ahead, the environmental offsets will make up for it. How could you trust them after this?''

A spokesman for Deputy Premier Jeff Seeney said the Government could approve the project it if it was satisfied the council had no substantial objection.

"The council has expressed concern regarding the retention pond and adjacent wetlands," he said. "The department is awaiting formal advice from the port regarding the outcome of discussions to resolve these concerns."

Council planning and development assessment chairman Amanda Cooper said the Government could approve the development regardless of the council's opinion.

"Council has raised concerns regarding the way in which impacts relating to the loss of biodiversity values of the retention pond and adjacent wetlands have been addressed," Cr Cooper said.

"It is council's view that the port undertake further consultation with respect to measures to offset the impacts of filling the pond and associated wetlands."

A port spokesman said a deal had been signed with Landcare to offset the loss of the lake by delivering four projects over five years with a value of more than $250,000.

The projects included work such as weed clean-up, revegetation and landscaping at the Minnippi Parklands, the Lindum Sandy Camp Rd freshwater wetland, Wynnum North roadside areas and Bayside Parklands.

Seven conservation and animal rights groups, including the RSPCA have formed an alliance to fight the port's proposal.

More than 150 species use the lake which is carrying more than 1000 birds.

UQ leads launch of world’s largest coral reef library

community, waterways/wetlands

Sep 242013

News release from UQ

The Catlin Seaview Survey last year made one of the great wonders of the world – Australia's Great Barrier Reef – accessible to anyone with an internet connection.

Catlin Seaview Survey: Deep Reef Science Team October 2012. ROV - Remote Operated vehicle on the Deep Reef

Now the visual access to the reef that has been seen on Google Street View will go even further, with the launch of the Catlin Global Reef Record, a free online resource that will make the survey's imagery invaluable to scientific researchers.

“The Catlin Global Reef Record is a game-changing analytic tool that scientists and reef managers around the world now have at their fingertips,” said UQ's Professor Ove Hoegh-Guldberg, who is also chief scientist of the Catlin Seaview Survey.

Visitors to the online library will be able to explore approximately 180,000 panoramic underwater coral reef images with another 200,000 panoramas expected by late 2014.

“Through the Record we will be able to monitor change in marine environments now and in the future,” Professor Hoegh-Guldberg said.

“It will be available to high schools, universities and scientists working on coral research.”

An estimated 50 per cent of coral reefs worldwide have been lost in the past 50 years, with 75 per cent of coral reefs today threatened by local and global stressors, including overfishing, pollution, unsustainable coastal development, ocean acidification and ocean warming.

Professor Hoegh-Guldberg, the Director of UQ's Global Change Institute (GCI), said many countries did not have the resources required to regularly measure the health of their coral reef ecosystems.

“As a result, there is often limited baseline data available for identifying the drivers of change on coral reefs,” he said.

“Without this information, understanding change and implementing coastal management strategies for arresting the downward trend in the condition of coral reefs can be extremely difficult.”

Catlin Seaview Survey: Deep Reef Science Team October 2012. Marine Biologist, Norbert Englebert of GCi at 40m depth.

The Catlin Global Reef Record is an initiative of the non-for-profit, Underwater Earth, and developed in collaboration with the GCI, the project's lead scientific partner.

Professor Hoegh-Guldberg said understanding change to coral reefs is important because almost 25 per cent of marine species live in and around coral reefs and one-eighth of the world's population expects to draw on marine resources, such as coral reefs, for their livelihood and wellbeing.

He said the images in the Record were scanned for coral species and automatically annotated using computer vision algorithms.

“The footage, meanwhile, is used to create 3D reconstructions of reef ecosystems, providing a visual way to assess reef populations,” he said.

Additional environmental data from satellites, such as ocean temperature, as well as information on regional coral bleaching activity, is included to allow for advanced analysis of worldwide reef health.

The data is captured using a custom-designed underwater camera, which integrates three digital SLR cameras positioned at an angle that allows the Catlin Seaview Survey team to record 360-degree panoramas.

Divers navigate the camera for two-kilometre transects along the reef, capturing high-definition imagery every three seconds.

By the end of 2014, about 300 reef locations will have been recorded, including the Great Barrier Reef, 10 countries in the greater Caribbean region, and the Coral Triangle region.

While many of the stresses on coral reefs originate from local sources, such as fishing activity and pollution, there is now urgent concern over the impact of ocean warming and acidification on coral reefs.

Professor Hoegh-Guldberg said if current trends in greenhouse gas emissions continued, atmospheric CO2 was expected to increase to more than 80 per cent above pre-industrial levels by 2050 – a rate of increase which had few, if any, parallels in the past 50 million years.

The effect of this rapid increase on marine ecosystems, in particular the Great Barrier Reef, would be devastating.

“The magnitude and rate of increases in sea surface temperatures and ocean acidity – both caused by the increasing concentrations of greenhouse gases, including CO2, in the atmosphere – is likely to exceed the ability of many marine species to adapt and survive,” he said.

“The Catlin Global Reef Record is one way we can help turn this around.”

Both the Catlin Global Reef Record and the Catlin Seaview Survey are sponsored by Catlin Group Limited, an international, specialty property/casualty insurer and reinsurer.

Images of the Catlin Global Reef Record can be seen here.

Contact: Professor Ove Hoegh-Guldberg, Director, UQ Global Change Institute, Ph +61 (0)401 106 604. Mark Paterson, Associate Director, Communications, UQ Global Change Institute, ph +61 (0) 409 411 110

About the Global Change Institute:
The Global Change Institute at The University of Queensland, Australia, is an independent source of game-changing research, ideas and advice for addressing the challenges of global change. The Global Change Institute advances discovery, creates solutions and advocates responses that meet the challenges presented by climate change, technological innovation and population change.

About Professor Ove Hoegh-Guldberg:
Ove Hoegh-Guldberg is the inaugural Director of the UQ Global Change Institute and Professor of Marine Science, at The University of Queensland, Brisbane, Australia as well as being Deputy Director of the ARC Centre of Excellence for Coral Reef Studies. He is the Queensland Smart State Premier's Fellow (2008-2013), Chief Scientist for the Catlin Seaview Survey and was elected to the Australian Academy of Science this year.

Eastern brown snake’s day at the beach

waterways/wetlands, wildlife

Sep 222013

Original story by Matt Deans, The Coffs Coast Advocate

Slither on the Sand. An eastern brown at Emerald Beach, Coffs Harbour Coast. Photo: Paul Widdowson

BASKING in the spring sunshine on the sand, this eastern brown snake surprised beachgoers and a flock of seagulls at Emerald Beach.

More likely to be found on sand tracks in the dunes, the snake was spotted at the water's edge before it took to the surf on Sunday afternoon.

Paul Widdowson, who captured this great image, said at first he thought the brown snake was sick or injured.

"The hungry seagulls were moving in closer and closer, but then it seemed to catch its breath, saw off the seagulls and with a flick and a hiss, calmly slid back into the breaking waves," Paul said.

"Head up, the snake swam along the beach then out on the rip in the corner until out of sight in quite big surf.

"It raised a few eyebrows on the beach especially among the surfers.

"We love nature, but don't want to share the line-up with this guy."

Steve McEwan of Reptile World identified the snake as a four-to-five foot male eastern brown.

"They do take to the water regularly, even the sea and this snake probably came off a headland," Steve said.

"The thing about the browns is that they aren't that common in Coffs Harbour.

"They usually prefer drier climates where you find their prey field mice, whereas black snakes are more common in our parts because they feed on frogs."

He said the Coffs Coast is home to 20 species of snakes and just six, including this guy, are dangerous to humans.

Antibacterial products fuel resistant bacteria in streams and rivers

environment, waterways/wetlands

Sep 212013

Original story at the Cary Institute of Ecosystem Studies

An artificial stream at Loyola University. Photo: John Kelly

Studies in Chicago metro-area unveil concerning trends, urban sites most impacted

(Millbrook, N.Y.) Triclosan – a synthetic antibacterial widely used in personal care products – is fueling the development of resistant bacteria in streams and rivers. So reports a new paper in the journalEnvironmental Science and Technology, which is the first to document triclosan resistance in a natural environment.

Invented for surgeons in the 1960s, triclosan slows or stops the growth of bacteria, fungi, and mildew. Currently, around half of liquid soaps contain the chemical, as well as toothpastes, deodorants, cosmetics, liquid cleansers, and detergents. Triclosan enters streams and rivers through domestic wastewater, leaky sewer infrastructure, and sewer overflows, with residues now common throughout the United States.

Emma Rosi-Marshall, one of the paper's authors and an aquatic ecologist at the Cary Institute of Ecosystem Studies in Millbrook, New York explains: "The bacterial resistance caused by triclosan has real environmental consequences. Not only does it disrupt aquatic life by changing native bacterial communities, but it's linked to the rise of resistant bacteria that could diminish the usefulness of important antibiotics."

With colleagues from Loyola University and the Illinois Sustainable Technology Center, Rosi-Marshall explored how bacteria living in stream and river sediments responded to triclosan in both natural and controlled settings. Field studies were conducted at three sites in the Chicago metropolitan region: urban North Shore Channel, suburban West Branch Dupage River, and rural Nippersink Creek.

Urbanization was correlated with a rise in both triclosan concentrations in sediments and the proportion of bottom-dwelling bacteria resistant to triclosan. A woodland creek had the lowest levels of triclosan-resistant bacteria, while a site on the North Shore Channel downstream of 25 combined sewer overflows had the highest levels.

Combined sewers deliver domestic sewage, industrial wastewater, and storm water to a regional treatment plant using a single pipe. Overflows occur when a pipe's capacity is exceeded, typically due to excessive runoff from high rainfall or snowmelt events. The result: untreated sewage flows directly into rivers and streams.

A combined sewer overflow on Chicago's North Shore Channel. Photo: John Kelly.

The research team found that combined sewer overflows that release untreated sewage are a major source of triclosan pollution in Chicago's North Shore Channel. In addition, their findings support past work that indicates sewage treatment plants can effectively remove triclosan from wastewater.

John Kelly of Loyola University Chicago, the paper's senior author, comments, "We detected much lower levels of triclosan at a site downstream of a sewage treatment facility as compared to a site downstream of combined sewer overflows. And we demonstrated a strong link between the presence of triclosan in the environment and the development of triclosan resistant bacteria."

Nearly 800 cities in the United States rely on combined sewer overflows, with the Environmental Protection Agency citing them as a major water pollution concern.

Artificial stream experiments, conducted at Loyola University, confirmed field findings that triclosan exposure triggers an increase in triclosan-resistant bacteria. In addition to the creation of these resistant bacteria, researchers also found a decrease in the diversity of benthic bacteria and a shift in the composition of bacterial communities. Most notable were a 6-fold increase in cyanobacteria and a dramatic die-off of algae.

Rosi-Marshall explains how these shifts could affect aquatic life, "Cyanobacteria are less nutritious than algae and can produce toxins. In triclosan-polluted streams and rivers, changes in microbial communities could negatively affect ecological function and animal communities."

The study is the latest in an ongoing effort to better understand the environmental and human health consequences of synthetic antimicrobials. Funding was provided by a grant from the Illinois Sustainable Technology Center.

Triclosan Exposure Increases Triclosan Resistance and Influences Taxonomic Composition of Benthic Bacterial Communities, Environ. Sci. Technol., 2013, 47 (15), pp 8923–8930

Authors:

Bradley Drury, Loyola University Chicago
John Scott, Illinois Sustainable Technology Center
Emma Rosi-Marshall, Cary Institute of Ecosystem Studies
John J. Kelly, Loyola University Chicago

The Cary Institute of Ecosystem Studies is a private, not-for-profit environmental research and education organization in Millbrook, N.Y. For thirty years, Cary Institute scientists have been investigating the complex interactions that govern the natural world. Their objective findings lead to more effective policy decisions and increased environmental literacy. Focal areas include air and water pollution, climate change, invasive species, and the ecological dimensions of infectious disease.

Overfishing of sharks is harming coral reefs

fisheries, waterways/wetlands

Sep 192013

Media release from Kim Luke, University of Toronto

Photo: Peter Verhoog, Dutch Shark Society

A team of scientists from Canada and Australia has discovered that a decline in shark populations is detrimental to coral reefs.

“Where shark numbers are reduced due to commercial fishing, there is also a decrease in the herbivorous fishes which play a key role in promoting reef health,” said Jonathan Ruppert, a recent University of Toronto PhD graduate. Ruppert was part of a team engaged in long-term monitoring of reefs off Australia's northwest coast.

Team leader Mark Meekan, of the Australian Institute of Marine Science (AIMS), said that the results might, at first glance, seem strange.

“However our analysis suggests that where shark numbers are reduced, we see a fundamental change in the structure of food chains on reefs," Meekan said.

“We saw increasing numbers of mid-level predators – such as snappers – and a reduction in the number of herbivores such as parrotfishes," said Meekan. "The parrotfishes are very important to coral reef health because they eat the algae that would otherwise overwhelm young corals on reefs recovering from natural disturbances."

According to Ruppert, the study comes at an opportune time – coral reefs are facing a number of pressures both from direct human activity, such as over-fishing, as well as from climate change.

The reefs studied are about 300 kilometres off the coast of northwest Australia where Indonesian fishers target sharks – a practice stretching back several centuries and which continues under an Australian-Indonesian memorandum of understanding.

Photo: Peter Verhoog, Dutch Shark Society

“The reefs provided us with a unique opportunity to isolate the impact of over-fishing of sharks on reef resilience, and assess that impact in the broader context of climate change pressures threatening coral reefs,” said Ruppert. “Shark fishing appears to have quite dramatic effects on coral reef ecosystems.

"Given that sharks are in decline on reefs worldwide, largely due to the shark fin trade, this information may prove integral to restoration and conservation efforts.”

Tracking studies show that, in many cases, individual reef sharks are closely attached to certain coral reefs. This means that even relatively small marine-protected areas could be effective in protecting the top-level predators and allowing coral reefs to more fully recover from coral bleaching or large cyclones which are increasing in frequency due to the warming of the oceans as a result of climate change.

The study will appear in the September 28 issue of journal PLOS One.

Lead author Ruppert completed his PhD at the University of Toronto and was also based at AIMS for part of his research. He is currently a post-doctoral research associate at York University. Other team members includedMarie-Josée Fortin of U of T’s Department of Ecology and Evolutionary Biology, Michael Travers of AIM and Luke Smith, the principal environmental scientist at Woodside Energy.

The research was funded by the Natural Sciences and Engineering Research Council of Canada and Woodside Energy of Perth, Australia.

Kim Luke is a writer with the Faculty of Arts & Science at the University of Toronto.

Reference: Jonathan L. W. Ruppert, Michael J. Travers, Luke L. Smith, Marie-Josée Fortin, Mark G. Meekan. Caught in the Middle: Combined Impacts of Shark Removal and Coral Loss on the Fish Communities of Coral Reefs. PLoS ONE, 2013; 8 (9): e74648 DOI: 10.1371/journal.pone.0074648

Mine’s poisonous legacy proves a test of wills

community, government, waterways/wetlands

Sep 182013

Original story by Ruby Jones, ABC News

Traditional owners in the Gulf Country want to work with government and industry to clean up one of the Northern Territory's most toxic legacy mines.

The old Redbank copper mine, south of Borroloola and about 40 kilometres from the Queensland border, closed in 1996 but still leaks copper sulphide into a nearby creek.

Redbank mine creek copper sulphide residue. Vivid colours mark the death of Hanrahan's Creek, downstream from the old Redbank copper mine.

The tranquil pools that form at Hanrahan's Creek look serene but the unnaturally bright green water and blue encrustations on its banks are telltale signs of high levels of pollution.

The copper sulphide concentration is so high in some sections of the creek that there is no longer anything living in the water.

Ian Pott is a traditional owner and used to swim in the creek downstream before it was poisoned.

He says there used to be turtles and fish in the water.

He is angry about what has happened and frustrated that there is seemingly no-one to blame.

"The companies that were here before failed it and the EPA (Environmental Protection Authority) has a lot to answer for leaving it this long," he said.

"No-one else is being held accountable at the moment because there is no-one else around."

The contaminated water comes from the mine upstream.

When the former owners abandoned it 17 years ago, they did not secure the main pit, and dangerous levels of dissolved metals have been leaking ever since.

Territory Mines Minister Willem Westra Van Holthe has travelled to the site and promised traditional owners it will be a personal priority to fix the problem.

"Redbank mine certainly rates highly as one of the worst legacy mines in the Territory," he said.

"But here we have an opportunity.

"It is a fairly small mine site, not withstanding the legacy is quite great, but there is a real opportunity to get this right.

“So that the traditional owners and all the other stakeholders involved in rehabilitating this site are kept fully informed, we want an open and transparent process in how we formulate the plans to fix this site.”

The Territory Government recently introduced a levy to try and pay for some of the costs of fixing legacy mine problems.

It is expected to raise just over $6 million in its first year.

Mr Westra Van Holthe says some of that levy will contribute to work at Redbank, although he can't guarantee that will happen in the next year.

COUNTING COSTS

But whatever money is spent won't come close to what is needed.

The full cost of rehabilitating the mine is not known because there has been no in-depth research done.

It is estimated to be anywhere between $10 million and $100 million.

Redbank Copper director Michael Fotios says he has been taken aback by the extent of the damage

"We didn't know a lot of the detail; the previous management really was non-existent," he said.

"When the company was reborn, a lot of the old people involved had long gone.

"We are still trying to find a lot of information or detailed information, reports, data about the old mining operation."

The company says it will use some of the capital it has raised for exploration to help fix the problem.

Mr Fotios believes the best hope for the long-term rehabilitation of the site is to restart mining operations.

That prospect is still a long way off.

"I don't think the site is really close to any mining plan laid down; it's at exploration stage," he said.

"There are significant copper resources here [but] it needs a lot more work to really prove up the viability of the mine."

Stuart Zlotkowski owns Wollogarang Station, the pastoral land the mine is on, which spans both sides of the border.

He is not keen on mining resuming but concedes it is probably the only way the site will be rehabilitated.

"We were always told that it would be cleaned up when the mine could afford to clean it up," he said.

"But because the bond they had in place to clean it up was so small, they couldn't force them to do it.

"It's been a ongoing thing, when we were always told over those last 18 to 19 years [that] soon as Redbank could afford to clean it up they would..

"The problem was, they never made any money, or we were told they never made any money, so it has got to this stage."

ROAD TO REHABILITATION

Mr Westra Van Holthe has not said how much the Territory Government will contribute towards rehabilitation.

The first thing it will do, he said, is form a working group with traditional owners.

"There's an enormous amount of engineering that firstly needs to take place here at the site," he said.

"Obviously, there will need to be some treatment done on the pit, and then they can start releasing water.

"We need to get on top of a whole bunch of issues here, including surface water and ground water."

Mr Pott hopes the Government and Redbank Copper will deliver on their promises.

"There's a bit of apprehension here, with all the TOs, because we've had these meetings before with Redbank mines and a few of the government departments but it's good to see the Minister out here," he said.

Mr Westra Van Holthe does not know how many abandoned legacy mines are leeching chemicals into the environment.

He estimates there are more than a thousand, and that it would cost more than a billion dollars to clean them all up.

"One of the things I am not going to do, and the government is not going to do to, is stick our head in the sand over these legacy mining issues," he said.

"Redbank is just one of many, and we will be working very hard to get on top of this, and other legacy mining issues in the Territory."

The Territory Government says it plans to send in dump trucks and bulldozers to begin rehabilitation at Redbank next year.

EPA INVESTIGATION

NT Environmental Protection Authority chairman Dr Bill Freeland says the water at the mine's leaking pit has a PH of two to three, close to the level of battery acid.

He says copper from the mine site has been detected in the water all the way down to the Queensland border.

"You have to go down about seven kilometres before you let livestock drink it, or humans drink it," he said.

"Over that length you've lost most of those macro invertebrates, the little, tiny critters that live in the bottom, which form the basis of food chains for things like fish and so forth."

Dr Freeland defended the EPA against claims of inaction.

"One of the things I did several months after I first got appointed was to make sure we did an investigation to find out what the situation really was," he said.

The results of that investigation are due to be released in November.

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