The Shark-o-meter

Black-tip reef shark

Black-tip reef shark. Picture by Tsumaguro.

Counting sharks isn’t quite like counting sheep – you can’t just sit underwater going ‘One, two, three …’ and hope for an accurate result. But it’s something that has to be done. It’s important for measuring the condition of the marine ecosystem and it informs policies about conservation or harvesting of sharks.

The counting sheep method can be unreliable because sharks respond to the presence of divers. Until now, though, simple counting has been one of the main methods used to work out coastal shark numbers.

Another counting method is video cameras with mounted baits. It also has its drawbacks. Bait tends to attract sharks – after all, that’s its job – so the count can be skewed depending on how far the smell has dispersed, and confused by other species entering the area.

One other good option is remote underwater video cameras without bait, but even these don’t provide a complete picture. They aren’t very good at estimating the density of sharks in an area.

So we put our thinking caps on, took our calculators out, and got to work on the problem. We built a model that can fill in the blanks.

It’s what’s called an agent-based model. This is a kind of computational model that works on the principle that simple actions generate complex behaviour. The model simulates what the sharks are doing when they interact with their environment – the reef crest, the coastline, other sharks – as a way to assess their effects on the system as a whole. You could think of it as rather like a video game, where you’re watching sharks swim around and sometimes passing the camera. Then we used this model to work out how often the video cameras would detect a shark, and compared what the model said to what the cameras found.

We surveyed 16 sites in Ningaloo Marine Park – eight of them in the marine sanctuary, the others in the recreation zone that adjoins it. Twice a day, at noon and dusk, we made observations. We later checked out the results against an earlier acoustic tagging survey to see if the model held up, and it did. That’s good news.

The even better news for conservation in this World Heritage Area is that the density estimates for this species are among the highest recorded.

Want to see some?


CO2 capture and storage – reducing carbon emissions from coal

In Australia we generate 75% of our electricity from coal. This creates a lot of CO2 emissions, with increasing concerns about global warming and climate change.

Dr Paul Feron wants to be able to use the coal without releasing carbon dioxide. He leads a multi-disciplinary team developing cost-effective methods to capture and store CO2.

Paul’s team has built and operated capture pilot plants illustrating that the technology can be retrofitted to coal-fired power plants as well as smelters, kilns and steel works.

He is focused on reducing the cost of the capture process, so that the technology can be taken up widely – not just in Australia, but also in developing countries which depend on coal for their energy supply . So that we can meet the world’s need for energy without adding to CO2 emissions. Hear Paul talk about his work.

Next week the National Carbon Capture and Storage conference is happening at Cockle Bay in Sydney from August 31 to September 3 – visit the website for more information.


Can we feed the world and save our species?

Australia’s Biodiversity series – Part 7: Farming, pastoralism and forestry

Australian agriculture provides food and fibre for millions of people in Australia and around the world, but it can come at a cost to our environment and biodiversity.

There is a range of intensities of primary production in Australia today. Hunting and gathering and use of fire to manipulate the abundance of native species is at the lowest end of the spectrum, then livestock grazing of native pastures, right through to complete replacement of native species for intensive cropping and forestry plantation (the latter requiring inputs in the way of fertilisers, machinery, chemicals etc.). The more intensive the production method, the more food and fibre can be produced per unit area, but with greater impact on biodiversity. Less intensive production methods provide opportunities for native species to coexist with production.

Better management of our agricultural landscapes can enhance biodiversity, and in turn, enhanced biodiversity can benefit agriculture through services like pollination and recycling nutrients in soils.

In the seventh video of our Australia’s Biodiversity series, Dr Sue McIntyre talks about the different intensities of agriculture in operation across Australia and what research is telling us about better managing practices to continue supporting biodiversity in those landscapes:

To find out more about managing agricultural landscapes for biodiversity, you might like to read the corresponding chapter of CSIRO’s Biodiversity Book.

Last week’s video looked at Indigenous perspectives on Australia’s biodiversity and its management. You can review it and the other videos in the series on our YouTube channel.


Will robots ResQu our rainforests from weeds?

By Carrie Bengston

Want to go for a walk in a rainforest? Join us!

We push our way past vines tangled around tree limbs in the dark, multilayered forest.  As we walk, we’re aware that we’re the only people in this tranquil environment. But it’s a place that’s home to rare and unique birds like the cassowary, a fantastic collection of fungi, and unusual mammals like the tree kangaroo. We step across clear, freshwater creeks (plus or minus leeches) and we listen to leaves rustle in the canopy as a thunderstorm approaches, rumbling in the distance.

Our rainforests are precious and incredibly biodiverse. For example, the rainforests of Far North Queensland, which include the iconic Daintree, occupy less than 0.2 per cent of Australia’s land mass. Yet they support more than ten percent of its flora, 36 per cent of its mammals and 48 per cent of its birds. Rainforests are confined to small patches clustered mostly in inaccessible, mountainous regions along the tropical coast. It’s important we look after these amazing habitats. Unfortunately, a purple-leafed weed, Miconia calvescens, has escaped from its natural habitat overseas via introduction into Aussie gardens and nurseries (which has since been banned) and has made its way into our World Heritage rainforests.

Miconia calvescens

The miconia calvescens, image: Forest & Kim Starr

Purple is a great colour. Don’t get us wrong. But these purple weeds have no place in our rainforests as they compete viciously for space, and squeeze out our native plants. The Miconia menace is taking over the rainforests of Tahiti and other countries. We don’t want that happening here. So we’ve called on an unlikely ally to stop Miconia getting a roothold – robotic technology.

We’ve been participating in a research project, Project ResQu, to trial robot helicopters that could do some of the weed spotting people currently do. Weed spotters work on the ground pushing through dense forest or flying above in manned helicopters, but robots can do the job better and safer. We recently put that to the test.

UAV in flight

UAV in flight. Image: Stefan Hrabar

The robots did well. The robot helicopters, fitted with radar and special cameras and given quirky names like ‘Hotel Golf’, found several Miconia infestations missed by other methods of surveillance. Here’s how we did it.

Will robots save the rainforest? They just might.

About Project ResQu:

Project ResQu is a two-year, $7M project led by the Australian Research Centre for Aerospace Automation (ARCAA) in a collaborative project between the Queensland University of Technology (QUT), CSIRO, Boeing and Insitu Pacific with the support of the Queensland State Government Department of Science, Information Technology, Innovation and the Arts.

Media contact: Emma Pyers, 03 5227 5123, 0409 031 658, emma.pyers@csiro.au


Powering Australia using mirrors in the outback

Fresh from creating a world record back in June, we’re taking our solar savvy to the bush.

At a time when electricity demand is falling across much of Australia, the opposite has been true for many mining centres in remote areas, where energy usage has been increasing.

Solar Thermal Research Hub

CSIRO’s solar thermal research hub in Newcastle, New South Wales.

These regions enjoy some of the bluest skies in the world, making them ideal for the use of solar thermal technology.

The problem is that at the moment the cost is too high.

Solar-thermal tower technology uses many mirrors (heliostats) that track the sun, concentrating its energy by reflecting light towards a receiver fixed on top of a tower. However conventional heliostats are expensive to install in remote areas due to the large number of components that need to be assembled on site, leading to higher electricity costs.

Electricity peak demand

Infographic explaining peak demand electricity.

Until now.

By changing the way heliostats are manufactured and controlled, our solar scientists are aiming to avoid the high cost of installation and maintenance in remote areas, providing an affordable renewable energy solution for the Aussie outback.

But that’s only part of the story.

We’re also working to improve the other components of the overall parts of the solar thermal system such as receivers, turbines and, perhaps most importantly, storage. Thermal energy can be stored relatively cheaply compared to some other technologies, so there is great potential for large scale power generation regardless of when the sun is shining.

Solar electricity can be transported through the grid from our country’s sunniest areas into cities and suburbs, and by making use of storage this can happen at the times when demand (and prices) are highest. This can have a positive impact on electricity prices by reducing peak demand caused by the use of air-conditioners on hot days.

To find out more about our solar thermal research, check out our website.

This three-year heliostat project is supported through $1 million of funding from the Australian Renewable Energy Agency (ARENA). CSIRO will work in partnership with Diver Consolidated Industries and RioGlass Solar on the project.

Media contact: Eamonn Bermingham, telephone: 08 6436 8627 or email: eamonn.bermingham@csiro.au


Spring forth and eat dung

A male Onthophagus vacca dung beetle

Onthophagus vacca – getting into it in WA

There are about 28.5 million head of cattle in Australia. Each one produces between ten and 12 cowpats a day, at an average 2.5kg each. Over a 14-day period, that’s about 14 million tonnes of dung. And every one of those cowflops can generate about 3000 flies in that time. But you may have noticed that Australia hasn’t been buried in manure or completely blanketed in flies. That’s because, for more than 40 years, we’ve been working to make sure cow dung doesn’t hang around, polluting pastures and waterways and providing the ideal breeding ground for flies.

This is a special week for us. One of our two new species of European dung beetle is ready for field release. The other is planned for release in 2015.

Our scientist, Dr Jane Wright, personally carried her shy but important companions, Onthophagus vacca, (a native of France and Spain) from Canberra to Western Australia. The spring-active dung beetles will be burrowing into new homes at field sites around Kojonup in Western Australia. These sites were chosen because they are home to numerous large herds of cattle, which means a lot of cow dung is available.

Here they are, making themselves at home.

Up until now, there has been a gap between one species of beetle settling down for a well-earned break and the next gearing up for action. These new beetles have been carefully selected to fill the seasonal break in activity in early spring across southern and western Australia. By introducing the spring-active beetle, the long term goal is to ensure dung is buried in early spring, getting the nutrients into the ground and accessible to the plant roots. The result is increased pasture productivity and reduced runoff of nutrients into waterways.  Another benefit is that the beetles will compete with bush flies for the dung, thus slowing the buildup of fly numbers over spring, enabling the existing beetles to have a greater impact on fly populations over summer.

With financial support from Meat and Livestock Australia and WA Agriculture and Food, we imported two new species of dung beetle in 2012. These were placed in quarantine and set up to breed. Then their eggs were surface-sterilised following AQIS protocols. Following that the eggs were taken into the laboratory outside quarantine and transferred to artificial brood balls. These beetles were the start of a laboratory colony that has allowed us to produce sufficient beetles for field releases, like this one.

If you’d like to learn more about these little scuttling wonders, there’s a more in-depth article over at The Conversation.


Bungees get wet – for science

Bungee jumper

Not this kind of bungy. Image: Flickr/fauzay

When you hear the word ‘bungee’ you don’t immediately think of ocean research. But the daredevil’s rubbery, stretchy friend is now doing its bit to assist in ocean and coastal science.

In order to hold monitoring equipment in place, marine and aquaculture researchers currently use chain to attach their equipment to moorings anchored to the ocean floor.

This is effective, but it can have some undesirable side effects. Marine chain is heavy. It has to be to withstand the power of the ocean. Unfortunately, this means that the weight of the chain moorings can damage the delicate sea floor, gouging bits out as it drags along.

Chain also takes up a lot of space. Because there needs to be some give (to prevent it from snapping), the chain needs to be much longer than the depth of the water. This is also a factor for aquaculture – the more ocean floor real estate occupied by chain, the less room they have for their production.

So what if there were a mooring that dispensed with the need for all that chain? A little lateral thinking, and … meet our home-grown bungee mooring, developed in partnership with Hobart-based company Specialised Industrial Products.

Just the same way as a standard bungee cord stretches and stretches and S-T-R-E-T-C-H-E-S, so does the rubber cord attached to the mooring hardware – up to five times its length at rest. This allows it to move with the dynamics of the water, instead of resisting it. As a result, the mooring can be smaller, lighter and take up less space on the ocean floor.

A bungee that goes UP.

A bungee that goes UP.

Not only that – the slimline design means it’s less vulnerable to fouling, which is the encrusting of small marine animals, plants and algae on the surface. That reduces the drag and load even further. Stretching instead of straining also lessens the stress on the coupling points, saving investment costs, maintenance cost and downtime. Our new bungee cords are estimated to have twice the working life of a traditional chain mooring, at about the same initial cost – around $1000 each.

This is just one of a, er, raft (see what we did there?) of marine innovations we have made in collaboration with industry. For more information contact Tim Lynch on tim.lynch@csiro.au or (03) 6232 5239.


Follow

Get every new post delivered to your Inbox.

Join 3,145 other followers