Shark nets and culls don’t necessarily make Australian beaches safer



AAP Image/Sea Shepherd Australia

George Roff, The University of Queensland and Christopher Brown, Griffith University

Most of the 24 million annual visitors to Queensland don’t notice the series of seemingly innocuous yellow buoys at many popular beaches. Beneath the waves lies a series of baited drumlines and mesh nets that aim to make Queensland beaches safe from the ominous threat of sharks.

Earlier this week the Queensland government lost a legal challenge in the Federal Court to continue its shark culling program in protected areas of the Great Barrier Reef, and Fisheries Minister Mark Furner has written to the federal government to request legal changes to keep the program operating.




Read more:
Why we’re opposing Western Australia’s shark cull: scientists


Since the Queensland Shark Control Program began in 1962, more than 50,000 sharks have been removed from Queensland beaches at a cost of some A$3 million per year.

While proponents of the program argue the absence of human deaths at beaches with shark control gear is proof of the program’s success, leading shark experts are not so sure.

Can shark control programs control sharks?

Large sharks roam across very large swathes of the ocean.
Photo courtesy of Juan Oliphant, Author provided

Through a series of baited drumlines and mesh nets, shark control programs aim to reduce local populations of large sharks, thereby reducing the number of times humans and shark meet along our coastline.

This approach assumes that the risk of shark bites directly correlates with the number of sharks, yet evidence for this is surprisingly lacking. As part of its safety at the beach program, the Queensland government states that:

Scientists believe that resident sharks may learn that nets and drumlines placed in their local areas represent an obstacle and actively avoid them. This in itself deters and reduces the local population of large sharks in that particular area.




Read more:
FactFile: the facts on shark bites and shark numbers


There are two problems with this logic. First, large apex sharks are not local to individual beaches – satellite tracking data indicates they are highly mobile, moving thousands of kilometres across coasts, reefs and open oceans every year. Sharks tagged in the Whitsundays and Cairns have travelled thousands of kilometres throughout the Great Barrier Reef and beyond.

Second, there’s no clear evidence that sharks avoid drumlines. In fact, baited drumlines and nets actively attract, not deter, large sharks. Similar programs in Hawaii were stopped after an expert review concluded their effectiveness had been overstated.

Do shark control programs make our beaches safer?

Nets do not place an impenetrable barrier between swimmers and sharks. It is true only one death has occurred at beaches with nets and drumlines, but over the same period there were 26 unprovoked non-fatal incidents.

While a reduction in fatalities is often attributed to the success of the shark control program, it could also be that reduced response times and better medical interventions are more successful at saving lives in recent decades.

Culls, nets and baited drumlines are a blunt tool, unable to completely remove the threat of people and sharks meeting on our beaches. Advances in technology and improved education of swimmers may be a more effective way to create safer beaches in Queensland with less ecological cost.

Smart technology

Modern technology allows us to help people avoid sharks, by modifying our behaviour at beaches. Shark-detecting drones are being trialled on New South Wales beaches as part of that state’s A$16 million shark management strategy, allowing for real-time monitoring of popular coastal areas.

Technology like drones and smart buoys are increasingly good at spotting sharks.
Matt Pritchard/Wikimedia Commons

Underwater “clever buoys” installed at NSW beaches in place of baited drumlines allow for real-time detection of sharks using sonar technology, instantly notifying lifeguards of the location, size and direction of sharks. Solar-powered, beach-based shark warning systems operate on remote beaches in Western Australia, cutting the response time between shark sightings and authorities alerting beachgoers from nearly an hour to a matter of minutes.

Education about shark behaviour can also help. Sharks are more active in certain places, like river mouths, and at certain times, such as at dawn and dusk.

In fact, the Queensland government is prioritising research into shark and human behaviours. This research could support education that mitigates the risk of shark interactions, without causing ecological harm.

Earlier this year the Queensland government committed to a A$1 million annual funding boost towards trialling alternative technologies. Adoption of modern innovations and better education for the general public would improve beach safety while avoiding the expensive and ineffective methods of culls, baited drumlines, and nets.

The cost of shark control programs

While we will never have an exact idea of how many sharks used to roam the eastern coastline, historical estimates from shark control programs suggest that the number of large sharks has declined by 72-97% in Queensland and by as much as 82% in NSW since the middle of the 20th century.

Shark nets, culls and baitlines are expensive and ineffective.
Nicole McLachlan, Author provided

NSW and Queensland shark control programs combined have removed more than 1,445 white sharks from the eastern Australian coastline since the middle of the 20th century. To put this in context, current estimates indicate that the eastern population of white sharks sits at around 5,460 individuals in total.




Read more:
Sharks: one in four habitats in remote open ocean threatened by longline fishing


The idea that sharks numbers have boomed in recent years represents a classic example of shifting baseline syndrome. The number of sharks on our beaches may seem to have grown since the late 1990s, but it is a fraction compared with a 1960s baseline, and long-term trends indicate that declines are ongoing.

The number-one priority at our beaches is keeping swimmers safe. At the same time, we have a responsibility to protect threatened and endangered species. There are smarter ways to manage both humans and sharks that will make our beaches safer and help protect sharks.The Conversation

George Roff, Postdoctoral Research Fellow, The University of Queensland and Christopher Brown, Senior Lecturer, School of Environment and Science, Griffith University

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

Australia’s pristine beaches have a poo problem



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

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

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

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




Read more:
Sewerage systems can’t cope with more extreme weather



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

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

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

Understanding the problem from a national perspective

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

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

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

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




Read more:
Curious Kids: Where does my poo go when I flush the toilet? Does it go into the ocean?


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

The best and worst offenders

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

Clean Ocean Foundation CEO John Gemmill said:

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

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

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

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

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

Recycling sewage

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

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




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


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

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

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

What the rest of Australia can learn from WA

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

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




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


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

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

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

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

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

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

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

Contested spaces: saving nature when our beaches have gone to the dogs



Image 20170308 24179 dflmw8
Early in the morning and late in the evening is when shorebirds escape disturbance on the beaches on which their survival depends.
Arnuchulo

Madeleine Stigner, The University of Queensland; Kiran Dhanjal-Adams, Centre for Ecology & Hydrology, and Richard Fuller, The University of Queensland

This is the ninth article in our Contested Spaces series. These pieces look at the conflicting uses, expectations and norms that people bring to public spaces, the clashes that result and how we can resolve these. The Conversation


There’s no doubt about it, Australians love the beach. And why not? Being outdoors makes us happy, and all beaches are public places in Australia.

Head to a beach like Bondi on Christmas Day and you’ll share that space with more than 40,000 people. But we aren’t just jostling with each other for coveted beach space. Scuttling, waddling, hopping or flying away from beachgoers all around Australia are crabs, shorebirds, baby turtles, crocodiles, fairy penguins and even dingoes.

Beaches are home to an incredible array of animals, and sharing this busy space with people is critical to their survival. But, if we find it hard to share our beaches with each other, how can we possibly find space for nature on our beaches?

Beach birds

Here’s a classic example of how hard it is to share our beaches with nature. Head to a busy beach at dawn, before the crowds arrive, and you will most likely see a number of small birds darting about.

You may recognise them from the short movie Piper – they are shorebirds. As the day progresses, swimmers, kite surfers, dog walkers, horse riders, 4x4s and children descend upon the beach en masse, unwittingly disturbing the shorebirds.

We share beaches with an extraordinary array of life, including many shorebirds.

Unlike seabirds, shorebirds do not spend their life at sea. Instead, they specialise on the beach: foraging for their invertebrate prey, avoiding waves, or resting.

However, shorebird numbers in Australia are declining very rapidly. Several species are officially listed as nationally threatened, such as the critically endangered Eastern Curlew.

There are few places you can let your dog run for as long and as far as it pleases, which is one of the reasons beaches appeal to dog owners. But this disturbance results in heavy costs to the birds as they expend energy taking flight and cannot return to favourable feeding areas. Repeated disturbance can cause temporary or permanent abandonment of suitable habitat.

The world’s largest shorebirds, Eastern Curlews are critically endangered – and Australia is home to about 75% of them over summer.
Donald Hobern/flickr, CC BY

The fascinating thing about many of these shorebirds is that they are migratory. Beachgoers in Korea, China, Indonesia or New Zealand could observe the same individual bird that we have seen in Australia.

Yet these journeys come at a cost. Shorebirds must undertake gruelling flights of up to 16,000 kilometres twice a year to get from their breeding grounds in Siberia and Alaska to their feeding grounds in Australia and New Zealand. In their pursuit of an endless summer, they arrive in Australia severely weakened by their travels. They must almost double their body weight before they can migrate again.

And these birds must contend with significant daily disruption on their feeding grounds. A recent study in Queensland found an average of 174 people and 72 dogs were present at any one time on the foreshore of Moreton Bay, along Brisbane’s coastline. And 84% of dogs were off the leash – an off-leash dog was sighted every 700 metres – in potential contravention of regulations on dog control.

Managing the menagerie

One conservation approach is to set up nature reserves. This involves trying to keep people out of large areas of the coastal zone to provide a home for nature. Yet this rarely works in practice on beaches, where there are so many overlapping jurisdictions (for example, councils often don’t control the lower areas of the intertidal zone) that protection is rarely joined up.

The beach-nesting Hooded Plover is unique to Australia where it is listed as vulnerable (and critically endangered in NSW).
Francesco Veronesi/Wikimedia Commons, CC BY-SA

Benjamint444/Wikimedia Commons, CC BY-SA

However, our work at the University of Queensland shows we don’t need conservation reserves in which people are kept out. Quite the reverse. We should be much bolder in opening up areas that are specifically designated as dog off-leash zones, in places where demand for recreation is high.

In the case of Moreton Bay, 97% of foraging migratory shorebirds could be protected from disturbance simply by designating five areas as off-leash recreation zones. Currently, dogs must be kept under close control throughout the intertidal areas of Moreton Bay.

By zoning our beaches carefully, the science tells us that the most intense recreational activities can be located away from critical areas for nature. And there’s no reason why this logic couldn’t be extended to creating peaceful zones for beach users who prefer a quiet day out.

By approaching the problem scientifically, we can meet recreational demand as well as protect nature. Proper enforcement of the boundaries between zones is needed. Such enforcement is effective when carried out in the right places at the right time.

We believe that keeping people and their dogs off beaches to protect nature is neither desirable nor effective. It sends totally the wrong message – successful conservation is about living alongside nature, not separating ourselves from it.

Conservationists and recreationists should be natural allies, both working to safeguard our beautiful coasts. The key is to find ways that people and nature can co-exist on beaches.


You can find other pieces published in the series here.

Madeleine Stigner, Research assistant, The University of Queensland; Kiran Dhanjal-Adams, Research Associate Ecological Modeller, Centre for Ecology & Hydrology, and Richard Fuller, Associate Professor in Biodiversity and Conservation, The University of Queensland

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

Dolphin-Eating Sharks Close Australian Beaches for 7 Days Straight


TIME

Two great white sharks have been spotted in the waters of Newcastle, Australia, prompting officials to shut down the beaches for seven consecutive days.

The sharks, one estimated around three meters long, the other five meters, have been spotted chasing, attacking and feeding on dolphins, whose carcasses now float in the water and wash up on shore.

Newcastle City Council announced that it is “not safe for anyone to be in the water,” and will not re-open the beaches again until at least 24 hours have passed since the last sighting.

[The Sydney Morning Herald]

Read next: Marine Biologists Capture Rare Photo of a Shark Birth

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Media Release: Myall Coast Beaches Closed to 4WDs


The link below is to a media release concerning the closure of Myall Coast beaches to vehicles due to weather conditions.

For more visit:
http://www.environment.nsw.gov.au/media/OEHmedia1306201300.htm