Seabirds are eating plastic litter in our oceans – but not only where you’d expect

albatross marine debris

Chris Wilcox, CSIRO; Britta Denise Hardesty, CSIRO, and Erik van Sebille, Imperial College London

Many of you may have already seen the photograph above, of an albatross carcass full of undigested plastic junk. But how representative is that of the wider issue facing seabirds?

To help answer that question, we carried out the first worldwide analysis of the threat posed by plastic pollution to seabird species.

Our study, published today in Proceedings of the National Academy of Sciences, found that nearly 60% of all seabird species studied so far have had plastic in their gut. This figure is based on reviewing previous reports in the scientific literature, but if we use a statistical model to infer what would be found at the current time and include unstudied species, we expect that more than 90% of seabirds have eaten plastic rubbish.

Rising tide of plastic

Our analysis of published studies shows that the amount of plastic in seabird’s stomachs has been climbing over the past half-century. In 1960, plastic was found in the stomachs of less than 5% of seabirds, but by 2010 this had risen to 80%. We predict that by 2050, 99% of the world’s seabird species will be accidentally eating plastic, unless we take action to clean up the oceans.

Perhaps surprisingly, we also found that the area with the worst expected impact is at the boundary of the Southern Ocean and the Tasman Sea, between Australia and New Zealand. While this region is far away from the subtropical gyres, dubbed “ocean garbage patches”, that collect the highest densities of plastic, the highest threat is in areas where plastic rubbish overlaps with large numbers of different seabird species – such as the Southern Ocean off Australia.

Expected number of seabird species ingesting plastic. PNAS

Seabirds are excellent indicators of ecosystem health. The high estimates of plastic in seabirds we found were not so surprising, considering that members of our research team have previously found nearly 200 pieces of plastic in a single seabird. These items include a wide range of things most of us would recognise: bags, bottle caps, bits of balloons, cigarette lighters, even toothbrushes and plastic toys.

Seabirds can have surprising amounts of plastic in their gut. Working on islands off Australia, we have found birds with plastics making up 8% of their body weight. Imagine a person weighing 62 kg having almost 5 kg of plastic in their digestive tract. And then think about how large that lump would be, given that many types of plastic are designed to be as lightweight as possible.

The more plastic a seabird encounters, the more it tends to eat, which means that one of the best predictors of the amount of plastic in a seabird’s gut is the concentration of ocean plastic in the region where it lives. This finding points the way to a solution: reducing the amount of plastic that goes into the ocean would directly reduce the amount that seabirds (and other wildlife) accidentally eat.

That might sound obvious, but as we can see from the stomach contents of the birds, many of the items are things people use every day, so the link to human rubbish is clear.

Plastic from a dead flesh-footed shearwater, amounting to 8% of the bird’s body weight. Britta Denise Hardesty, Author provided

Our study suggests that improving waste management would directly benefit wildlife. There are several actions we could take, such as reducing packaging, banning single-use plastic items or charging an extra fee to use them, and introducing deposits for recyclable items like drink containers.

Many of these types of policies are already proving to be locally effective in reducing waste lost into the environment, a substantial portion of which ends up polluting the ocean.

One recent study of industrial practices in Europe found that improved management of plastic led to a clear reduction in the number of plastic items found in seabirds in the North Sea within a few decades. This is encouraging, as it suggests not only that the solutions are effective, but also that they work in a relatively short time.

Given that most of these items were in someone’s hands at some point, it seems that a simple behaviour change can reduce a global impact to our seabirds, and to other marine species as well.

This work was carried out as part of a national marine debris project supported by CSIRO and Shell’s Social investment program, as well as the marine debris working group at the US National Center for Ecological Analysis and Synthesis, University of California, Santa Barbara, with support from Ocean Conservancy.

The Conversation

Chris Wilcox is Senior Research Scientist at CSIRO; Britta Denise Hardesty is Senior Research Scientist, Oceans and Atmosphere Flagship at CSIRO, and Erik van Sebille is Lecturer in oceanography and climate change at Imperial College London

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


Australia: riding on the insect’s back

termite

Love me tender: the giant northern termite, an endemic species living in tropical Australia. 

David Yeates, CSIRO

As you may have spotted, the title of this article is a cheeky reference to the famous saying that Australia rides on the back of a particular woolly ruminant. The reference dates back to 1894, when the wool industry was one of the primary sources of Australia’s prosperity.

Wool was our main export commodity from 1871 to the 1960s. For more than a century, the golden fleece drew pastoral workers and professionals to regional Australia, and sustained many a country town.

It is likely that most people would consider the native birds and animals in the farm shelterbelt to be the main source of agricultural biodiversity. However, the most diverse and important biodiversity is much smaller. And it’s invertebrate.

Looking beneath the farmer’s feet we would find countless insects and other invertebrates living out their lives, and in so doing providing services that we take freely and for granted.

Beneficial bugs

While Australia long ago hopped off the sheep’s back, insects and other invertebrates still do things that sustain our society. Yes, “sustain”. In recent years, agricultural economists have put estimates on the values of some of these insect services to human society.

In one 2009 example, the total economic value of insect pollination of agricultural crops worldwide was A$220 billion. A sizeable fraction of this pollination occurs in Australia by species such as the European honeybee, and many thousands of native bees and flies.

Insects are a bit like car keys, you only notice them when they are missing. During the mid noughties, honeybees died in large numbers in Europe and the United States, a phenomenon known as colony collapse disorder (CCD). The cause of CCD is complex and not yet fully understood.

But the effects were transparent. Profits from pollinated crops, such as almonds decreased. The prices of some foods increased significantly, because farmers had to pay more for disease-free bees, often importing them from CCD-free Australia.

Honey bee hard at work boosting agricultural productivity. Bob Peterson/Flickr, CC BY-SA

Another good example is the service that introduced dung beetles provide. Australia’s cattle herd was estimated at 30 million in the 1970s, each animal producing 10 pats per day, covering over 2.5 million hectares of pasture each year.

Millions of bush flies (Musca vetustissima) also bred in the dung. Overseas these dung pats would have been recycled into soil nutrients by the local dung beetles that buried small chunks of the dung in the soil to rear their young. However, Australia’s native dung beetles are adapted to feed on and bury dry, fibrous marsupial dung, and avoid the much more moist cattle dung.

CSIRO introduced dung beetles from Europe and Africa in the 1970s and 1980s that buried cattle dung underground so that it became a fertiliser for use by grass and other plants. The burrowing activity of the beetles also aerated the soil. And it also provided another important service: controlling the bush fly plague by removing and burying the dung that bush flies were breeding in.

Australia’s outdoor café owners probably don’t know it, but they owe at least part of their clientele to the silent work of introduced dung beetles working tirelessly in the agricultural districts surrounding our cities, once the source of most of our bush flies.

If you want to know more about the dung beetle story, watch the documentary The Great Australian Fly by 360 degree films, which can be found on ABC’s iView.

Great engineers

We often have an ambiguous relationship with insects, entire groups are prejudiced because of a few pest species. Termites are an excellent case in point. In most cases we only think of the damage they can do to timber in buildings.

Termites are impressive builders, dotting the landscape with their imposing structures. Bob Peterson/Flickr, CC BY-SA

But termites are in fact great soil engineers. They play a key role in the functioning of many tropical and subtropical landscapes, such as those found over much of northern Australia. They decompose wood and grass, and they are also social creatures, living in great colonies that sometimes produce a characteristic mound. Their region of influence in the soil is termed the termitosphere, and this is where termites are busy nutrifying, aerating, moistening and mixing the soil.

Termites are small but numerous, and their biomass can exceed 50 grams per square metre, much greater than mammalian browsers in the same environments. Because termite mounds are intense, crowded insect cities full of life, growth, decomposition, waste and death, soil nutrient levels are much higher around them – up to seven times higher in one Australian example.

Termite excavations move soil around between layers, and create tiny holes in the soil that allow air and moisture to infiltrate. Termites modify many soil characteristics, improving and increasing the productivity of soils, and they do this free of charge over much of northern Australia. Overall, the positive benefits of the termitosphere are far greater than the costs.

Hidden biodiversity

With insects being such a valuable resource, and part of the natural heritage of a first world country such as Australia, you would think that we had a good handle on our insect diversity.

The reality is very different. We have only managed to catalogue around 25% of our insect biodiversity at species level. The remaining 75% cannot be managed well because we don’t have the basic information required such as what it is, where it occurs, and what it does.

For example, there are around 260 named termite species in Australia, but this represents less than half the total number, and many of these unnamed species are represented in CSIRO’s Australian National Insect Collection. Imagine trying to manage a library without knowing how many books you had on hand, and what they were about.

In other areas such as medicine and physics we have learnt the importance of small things: germs, atoms, chemical molecules etc. We gain knowledge in these areas by reducing the system to its basic components and working on the properties of these parts and their interactions.

But in biodiversity science we are still trying to understand and manage ecosystems with only a basic knowledge of a subset of the biological components in the system. Australian ecosystems ride on the insect’s back, and we would be better off economically, socially and environmentally if we invested more in understanding our insect fauna.

The Conversation

David Yeates is Director of the Australian National Insect Collection at CSIRO

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


You make me wanna swoop: dispelling magpie myths

U wot m8? Not even our Canberra Deep Space Communication Complex is safe

U wot m8? Not even our Canberra Deep Space Communication Complex is safe.

With warmer weather showing signs of returning across the country, so too are many of spring’s delights: the flowering of plants, greening of trees and rolling of cuffs all testament to the fact that the worst of winter is behind us.

Unfortunately, it’s not all lamingtons and Cherry Cheer at this time of year. For there is also a suburban menace lurking just over the horizon: a black and white marauder waiting to terrorise unsuspecting picnickers, exercisers and office workers alike.

Yep, September is magpie season.

Magpie

If this image doesn’t send a primordial chill down your spine, you’ve obviously never spent the month of September in suburban Australia. All around the country, roadsides, reserves and office blocks turn into battlegrounds as the Australian magpie looks to protect its patch from any and every threat it can lay its beak on.

So why do magpies swoop us humans – is it to defend their young, or their territory? Or are they just bird jerks?

And most importantly, is there any way we can guard against them?

There was an illuminating paper co-authored by academics from Deakin and Griffith universities, titled Attacks on humans by Australian Magpies (Cracticus tibicen): territoriality, brood-defence or testosterone? The paper, published in our Emu – Austral Ornithology journal back in 2010, looked to study three common hypotheses behind magpie-human attacks, particularly in suburban areas. Were the attacks triggered by territoriality, brood-defence or (magpie) testosterone, the authors asked?

The response of 10 pairs of aggressive magpies to natural levels of human intrusion was compared with that of 10 non-aggressive pairs. Behavioural observations strongly supported the contention that attacks on humans resemble brood-defence and did not support an association with territoriality. The study also found no support for the suggestion that testosterone levels correlated with aggressiveness towards humans: male testosterone peaked immediately before laying and was significantly lower during the maximum period of attacks directed at people. Moreover, there were no differences in the testosterone levels of aggressive and non-aggressive male magpies. The pattern of testosterone production over a breeding cycle closely resembled that of many other songbirds and appeared not to influence magpie attacks on humans.

So, brood-defence can be identified as the cause of attacks.

But, of more interest to posties, cyclists and small children with blonde hair in particular: what makes magpies more likely to attack some people, and not others?

Enter the brave scientists of CSIRO Black Mountain in Canberra. In 2010 (it must have been a bad year!) a particularly aggressive maggie was nesting on the foot and cycle path between the Australian National University and our Black Mountain site. With all types of magpie-repelling adornments being attached to cycle helmets with varied successes, and (figurative) public service and academia corpses littering the notorious path, our enterprising colleagues decided to add some scientific scrutiny to the debate: how do you deter a mad magpie?

The results can be seen in the following two YouTube clips that, in 2010 terms, broke the Internet.

We can’t really condone the results: we would never advise riding your bike without a helmet. But these videos also do quite clearly dispel the myth that helmet decorations do anything to stop a swooper.

And really, what’s better than seeing public servants being attacked by a magpie to the soundtrack of Tricky’s Maxinquaye?

Want to learn more about this quintessential Aussie which, September aside, we do actually really like? Then check out this great book available through CSIRO Publishing: Australian Magpie – biology and behaviour of an unusual songbird.

And remember, keep your eyes to the sky.


Air Bee’n’Bee: have backpack, will travel

Bee with a backpack...of the sensor variety.

There is a lot of buzz around the ‘bee’utiful honey bee and its clever backpack

By Ali Green

It has long been suspected that honey bees, being the creatures of habit that they are, simply return to their familial hive homes at the end of a long day of foraging. But it seems for some bees, laying their hat in a particular hive doesn’t necessarily make it their home.

The data already gathered from tiny sensor backpacks placed on bees suggests that for some vagabond bees, sleeping over at a different hive is a regular part of their active social lives. So what does this devil-may-care attitude to bee social structure really mean? Bee Pajama parties? Promiscuous bees? Oh bee nice!

Bee bed jumping is just one of the intriguing insights our researchers are gleaning from the tiny sensors currently monitoring the behaviour of these little swingers… erm, stingers.

Why do we care about bee-haviour?

Honey bees are essential for food production. In fact they are responsible for one third of the food we eat through the pollination services they provide. Yet the health of honey bees on a global scale is under increasing pressure.

To ensure the sustainable production of crops dependent on honey bee pollination, we must protect and improve the health of our honey bee populations.

Enter the Global Initiative for Honey bee Health (GIHH). We’re proud to be leading this international alliance of researchers in a tightly focused, well-coordinated national and international effort to better understand the diverse stresses impacting bee health.

In order to learn more about these tiny creatures and the issues causing their population collapse, we’ve glued thousands of tiny sensor chips to the backs of bees. Don’t worry – the sensors weigh in at 5 mg each – a light load easily managed by honey bees! The little sensor backpacks work in much the same way as a vehicle e-tag system, with strategically placed receivers identifying and recording the movements of individual bees as they fly in and out of their hives, and feeding the information back to an Intel minicomputer that is remotely accessible.

These high-tech micro-sensors are being used to gather a wealth of complex data which is then analysed to determine best management practices for maintaining healthy and productive honey bee colonies.

What is the data telling us?

Here are a few interesting things we’ve learnt so far about the way bees operate – including their preferred sleeping arrangements!

The impact of losing the free pollination services provided by feral honey bees will be farmers paying beekeepers to bring bees in to pollinate their crops, resulting in price hikes in everything from cucumbers and oranges, to cashews and onions.

The proud pollinators: without the services of bees many of our favourite crops won’t be pollinated.

  1. By correlating bee movement data with environmental data, such as weather stats, we’ve learned that bees, like us, are not overly fond of conducting their outdoor activities in the rain. Instead they choose to forego foraging on inclement days and stay indoors instead. And who would blame them!
  2. The sensor system has even helped us observe differences between the routine of bees on two continents. We are tracking a colony of bees in Brazil and discovered that, unlike the lazier Tasmanian bees who prefer to sleep in and retire early, the Brazilian bees get to bed and wake up earlier, while indulging in a two hour siesta during the day.
  3. The data has also demonstrated that bees navigate by colour. Field experiments that involved labelling hives with different colour stickers have shown that individual bees soon identify with the colour on their hive, to the extent that they will follow their particular colour to a different hive if the stickers are moved around. This is terrific news for beekeepers who might use this information to divert healthy honey bees away from a hive in the process of collapse, simply by relocating their colour stickers.

Discoveries like these contribute to a better understanding and management of honey bee health;  increase environmental and economic benefits for farmers and beekeepers; and make a valuable contribution to sustainable farming practices and food security. Not bad for a 5 mg backpack!

We’d like to gather as much data as possible through the GIHH project to help us better understand honey bee behaviour and impacts on honey bee health. This means taking the project global. We’re calling on other research institutions around the world to contribute. If you’re interested, visit our GIHH page for more info.


Honey bee backpackers ready to tackle the world

Picture of bee with backpack

A bee with its backpack.

By Ali Green

“You never can tell with bees.” 
― A.A. Milne, Winnie-the-Pooh

Australia’s honey and hive product industry is worth a staggering $90 million a year. Not only that, but the humble honey bee is responsible for contributing an estimated $4-6 billion a year to Aussie crop production.

Without these little guys we’d miss out on approximately one third of the foods we currently eat and enjoy – foods like apples, berries, almonds, and… coffee!

Ponder if you will, a world without cafe lattes, blueberry almond friands and fruit salad – indulgences only made possible by the magic pollinating work of our friends the honey bees. Considering the key role that honey bees (Apis mellifera) play in sustaining our pollination-dependent crops, ensuring their health and happiness is critical.

The Global Initiative for Honey bee Health (GIHH)

The health of the honey bee is in jeopardy. Challenges such as Colony Collapse Disorder (CCD) and the Varroa mite pose a global threat to our bees.

In a world first, the Global Initiative for Honey bee Health (GIHH) will seek to address these threats through a world-wide data collection exercise.

Over the next few years we will be leading an international alliance of researchers, in collaboration with beekeepers and farmers, to place tiny sensors onto the backs of honey bees. Data collected through the ‘backpack’ sensor system will provide valuable insights into bee behaviour and inform the development of sustainable long term solutions for bee health.

Our researcher, Saul Cunningham, considers the honey bee to be a ‘super species’ because of its evolutionary success and impact on humans. Although an exotic species in Australia, the feral honey bee provides a valuable biodiversity and ecosystem service to the Australian environment through its pollination practices, as well as having an important role to play in crop production.

Saul describes Australia, with its warm climate and abundance of nectar-rich plants like Eucalypts, as a haven for feral honey bees.

“Australian agriculture gets a particularly generous service of free pollination from these guys,” Saul says.

“This free service will be all but lost when Varroa mites spread to Australia. And I say when, not if, because it is widely accepted that we cannot expect to remain Varroa-free in the long term.”

Varroa destructor mite

An external parasite of bees, the Varroa destructor mite is only about the size of a pinhead. The mites use specialised mouthparts to attack developing larvae or adults, resulting in deformed bees, reduced lifespan and ultimately the destruction of the colony or hive. These mites are the most significant pest of honey bees around the world.

Our team gathering data from a bee hive in the Huon Valley, Tasmania

Gathering data from a bee hive in the Huon Valley, Tasmania.

Dr John Roberts, who studies the viruses transmitted by the Varroa destructor mite, is equally pessimistic that it will happen. In saying that, he also agrees that Australia is in the enviable position of being able to learn from the damage control strategies of other countries.

“The Varroa destructor does what it says. It destroys – and it’s the feral honey bee population that is always hardest hit.”

According to John, feral honey bees living in tree hollows or natural hives that are not managed by beekeepers would be wiped out. Farmers of strawberries, almonds and other crops that rely on free pollination by the feral honey bees would be left stranded, as they have been in America and China.

“The impact of losing the free pollination done by feral honey bees will be farmers paying for beekeepers to bring bees in to pollinate their crops, resulting in price hikes in everything from cucumbers and cherries, to macadamias and onions,” John said.

“But you never know where technology will lead us. Our scientists or those in other countries might come up with new ways of managing bees somewhere on the planet, so Australia will be able to respond quickly and effectively when the destructive mite does get here.”

We most definitely want to maintain a Varroa-free status in Australia, so getting involved in projects and initiatives that look to increase our ability to detect early incursions is important.

And this is where the GIHH will play its role.

Analysis of the data gathered by the GIHH will provide valuable information to scientists, beekeepers, primary producers, industry groups and governments to achieve impacts around improved biosecurity measures, crop pollination, bee health, food production and better strategies on sustainable farming practices, food security and impacts on ecosystems in general.

As it stands, Saul and John assure us it’s unlikely the Varroa mite will cause a global food crisis… but it could turn apples into an expensive delicacy!

Get the full buzz on the Global Initiative for Honey bee Health.


Dwarf galaxies feel the blast from larger neighbours

A composite image of Centaurus A which has a dwarf galaxy ESO 324-G024 nearby. X-ray: NASA/CXC/SAO; Optical: Rolf Olsen; Infrared: NASA/JPL-Caltech

A composite image of Centaurus A which has a dwarf galaxy ESO 324-G024 nearby. X-ray: NASA/CXC/SAO; Optical: Rolf Olsen; Infrared: NASA/JPL-Caltech

Megan Johnson, CSIRO

Dwarf galaxies are the most abundant galaxies in the universe. Yet understanding how these systems behave in galaxy group environments is still a mystery.

These objects are notoriously difficult to study because they are very small relative to classic spiral galaxies. They also have low mass and a low surface brightness, which means that, to date, we have only studied the dwarf galaxies in the nearby universe, out to about 35 million light years away.

My collaborators and I have been studying a dwarf galaxy named ESO 324-G024 and its connection to the northern radio lobe of a galaxy known as Centaurus A (Cen A).

The giant radio lobes are comprised of high energy charged particles, mostly made up of protons and electrons, that are moving at extremely high speeds. The lobes were created from the relativistic jet (shown in the image at the top) that is blasting out of the central core of Cen A.

The giant radio lobes of Cen A. For scale, the entire image at the top of the article fits within the small black box shown here in the centre the two lobes. Megan Johnson, Author provided

The giant radio lobes of Cen A. For scale, the entire image at the top of the article fits within the small black box shown here in the centre the two lobes. Megan Johnson, Author provided

These energetic particles glow at radio frequencies and can be seen as the fuzzy yellow lobes in the centre of the image (above), together with the neutral hydrogen intensity (HI) maps of its companion galaxies. The lobes now occupy a volume more than 1,000 times that of the host galaxy shown in the image at the top, assuming the lobes are as deep as they are wide.

These HI intensity maps are part of a large HI survey of nearby galaxies called the Local Volume HI Survey (LVHIS). These maps have been magnified in size by a factor of 10 so that they can be seen on such a large scale and are coloured by their relative distances to the centre of Cen A.

A green galaxy is at virtually the same distance from Earth as Cen A, while blue galaxies are in front of Cen A (closer to us) and red galaxies are behind it (farther away).

One of the striking things about this image is that out of the 17 galaxies overlaid onto the Cen A field, 14 are dwarf galaxies.

An interesting dwarf

The one object that really interested me after making this image was the dwarf irregular galaxy ESO 324-G024 (just above the black box). It has a long HI gaseous tail that extends roughly 6,500 light years to the northeast of its main body and it is at nearly the same distance as Cen A.

These two pieces of information right away made this a system worthy of investigation because we thought that perhaps there is a connection between this dwarf galaxy and the northern radio lobe of Cen A.

Nothing like this has ever been seen before, probably because galaxies that have giant radio lobes like Cen A are usually hundreds of millions to billions of light years away. Cen A is a special galaxy because it’s only about 12 million light years from Earth.

From observations using the Parkes Radio Telescope and the Australian Telescope Compact Array we were able to conclude that ESO 324-G024 must actually be behind the northern radio lobe of Cen A.

This was an interesting result and it told us that the northern radio lobe must be inclined toward our line of sight, because ESO 324-G024 was at nearly the same distance as Cen A. This had previously been suggested by studying the jet way down in the core of the host galaxy, but it had never been confirmed in this way before.

A wind in the tail

Next we investigated the mechanism responsible for creating the HI tail in ESO 324-G024. We looked at the likelihood of gravitational forces from the large, central host galaxy of Cen A as a potential culprit for ripping out ESO 324-G024’s gas. But we determined that it is simply too far away from the central gravitational potential for gravity to have created the tail.

So we explored ram pressure stripping, which is thought to be a dominant force for removing gas in galaxies within these kinds of groups. Ram pressure is a force created when a galaxy moves through a dense medium, and thus experiences a wind in its “face”.

Here you can see the blue streak of gas and dust from spiral galaxy ESO 137-001 being stripped away by ram pressure as it hurtles through space.  NASA, ESA, CXC

Here you can see the blue streak of gas and dust from spiral galaxy ESO 137-001 being stripped away by ram pressure as it hurtles through space. NASA, ESA, CXC

It’s similar to holding a dandelion in your hand and then running as fast as you can go and watching the seeds blow away in the wind. At rest, the dandelion feels no wind and the seeds stay intact. But when you run, all of a sudden, the dandelion feels the wind created from your running and this wind blows away the seeds.

In this scenario, ESO 324-G024 is the dandelion and you represent gravity carrying the galaxy through space. We calculated the wind speed required to blow the gas out of ESO 324-G024 and compared this speed to the speed of ESO 324-G024 moving through space. It turns out that the two speeds did not match.

ESO 324-G024 seemed to be moving too slow for all of its gas to have been blown into its long tail. So we went back to our first conclusion about ESO 324-G024 being behind the radio lobe and surmised what may be happening.

Strong winds

We know that the charged particles inside the northern radio lobe of Cen A are moving extremely fast. If ESO 324-G024 is just now coming into contact with the posterior outer edge of the radio lobe of Cen A, which is likely due to its proximity to Cen A, then it is possible that ESO 324-G024 is not only feeling the wind generated from its own motion through space, but also the wind from the charged particles in the radio lobe itself.

This would be like you running with the dandelion and at the same time blowing on it. Therefore, we concluded that ESO 324-G024 is most likely experiencing ram pressure stripping of its gas as it passes close to the posterior edge of the northern radio lobe.

This means that these types of radio lobes must have wreaked havoc on their dwarf galaxy companions in the distant past. This is an interesting case study that showcases how dwarf galaxies may have been knocked about, blasted, by their larger companion galaxies.

Just how common are situations like this and how have they influenced dwarf galaxies over cosmic time? The answer is that we simply don’t know, but I look forward to exploring these questions.

Megan Johnson — Post doctoral researcher in dwarf galaxies at CSIRO

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


Diving for treasure to help protect the world’s great reefs

Clownfish posing for a photo. Photo: Boris Bialek/Flickr, CC BY-NC-ND

Clownfish posing for a photo. Photo: Boris Bialek/Flickr, CC BY-NC-ND

Sean Pascoe, CSIRO and Natalie Stoeckl, James Cook University

Amid growing demand for seafood, gas and other resources drawn from the world’s oceans, and growing stresses from climate change, we examine some of the challenges and solutions for developing “the blue economy” in smarter, more sustainable ways.

Diving the warm, crystal clear waters of Indonesia’s Raja Ampat Marine Park is an experience for the lucky few. Its coral reefs attract a huge variety of marine life, including turtles, manta rays and countless species of tropical fish – including the now iconic clownfish.

If you’ve gone diving there recently, or are planning a holiday, you may have noticed that the marine park fees have gone up sharply in past 12 months – as they have in many other parts of Indonesia, Malaysia and Thailand.

But you might actually be happy to discover why.

image-20150817-5124-175quzu

Yuxuan Wang/Flickr, CC BY-NC-ND

The cost of caring for coral reefs

The dive industry has long been criticised as contributing to declines in coral reef health around the world. Coral reefs globally are under increasing pressure from the cumulative impacts of fishing, shipping, and coastal development, as well as longer-term impacts due to climate change. And unless it’s managed, increased diving and snorkelling tourism can become just another environmental strain.

That’s not in anyone’s interests. Failure to adequately manage activities within reef areas is likely to lead to their degradation, which will make them less attractive to divers and other tourists in the long-term.

But taking better care of our reefs comes at a cost. It requires monitoring and surveillance, as well as ensuring users (such as divers) and beneficiaries (such as local businesses) of the reefs are aware of their impacts and understand how to avoid them.

Scuba diving off the Thai coast. Ilse Reijs and Jan-Noud Hutten/Flickr, CC BY

Across Indonesia, Malaysia and Thailand, dive tourism directly dependent on the health of coral reefs brings in around US$1.5 billion a year to local communities. Most of this is in remote areas, where alternative sources of income are limited.

Those three countries have set up a number of marine parks to protect their reefs. And about 70% of those parks have long had dive fees in place.

But the fees have typically been very low, while government contributions were also relatively constrained – which is why a 2006 study found that only about one in seven marine reserves in south east Asia had adequate financial resources.

That’s where learning from the Australian experience, together with modelling work from an international team of researchers, has helped provide a practical solution.

How tourists help pay to preserve the Great Barrier Reef

The Great Barrier Reef Marine Park is one of Australia’s great tourism international drawcards – for divers in particular – injecting an estimated AUS$5 billion into the economy and generating around 64,000 full-time equivalent jobs.

But right from the early days of establishing the Great Barrier Reef Marine Park, Australia had to grapple with how to pay for crucial conservation work.

That’s why divers and other visitors to the Great Barrier Reef Marine Park each pay an environmental management charge of AU$6 a day. That contributes around 20% of the AU$40 million annual management costs.

Modelling to test what impact this charge has on visitor numbers suggests that it is very small, and the gains in terms of financial resources for management far exceed any potential losses to local businesses – which, after all, also depend on the reef for their continued survival.

Smile for the camera – diving the Great Barrier Reef.  Brian Costelloe/Flickr, CC BY-NC

Smile for the camera – diving the Great Barrier Reef. Brian Costelloe/Flickr, CC BY-NC

Testing a model solution

But until a few years ago, the idea of charging higher fees was opposed by many tourism and related businesses in south east Asian diving communities, concerned that it might cause tourist numbers and earnings fall.

In 2013, a group of international researchers supported by the Asia-Pacific Network for Global Change Research worked with managers, resort owners and dive operators in Indonesia, Malaysia and Thailand to develop options for improved reef management in the region.

This included modelling what might happen if you increased dive fees to pay for reef conservation. That study predicted that even if the conservation fees were more than doubled, it was unlikely to deter many divers, who care about the places they go diving in.

It also predicted that the revenue raised for reef protection would far exceed the loss in tourism expenditure in local communities, and help ensure that the communities as well as the reefs would survive into the future.

What higher diving fees are funding

Since then, as any keen divers reading this might already have seen, user fees in many of their marine parks have been introduced or increased. For example, at the Raja Ampat Marine Park in Indonesia, fees for foreign visitors have doubled in 2015 to 1,000,000 Indonesian Rupiah (about AU$100) for an annual permit.

More modest fee increases (and fee levels) have also been seen in most Thai and Malaysian marine parks this year, with most now charging international visitors between AU$10 and AU$20 a day for access.

So what are you paying for? Among other things, divers are helping by paying more for rangers’ wages and for patrols to keep out illegal fishing, mining and poachers, as well as conservation and reef rehabilitation projects in the parks.

A turtle emerges from a hidey-hole in a coral off Indonesia’s coast.  Boris Bialek/Flickr, CC BY-NC-ND

A turtle emerges from a hidey-hole in a coral off Indonesia’s coast. Boris Bialek/Flickr, CC BY-NC-ND

But when you consider how much it costs to go on a diving holiday, being asked to pay the equivalent of a light meal is not too much to ask. Indeed, from the modelling study, most visitors gain substantially much more than this in terms of benefits from diving on these coral reefs, and could potentially contribute greater amounts to protect them for future generations.

By digging a little deeper, divers can do more than just go on holiday: they can contribute to longer-term conservation of some of the most extraordinary places on Earth.

 — Fisheries Economist, Oceans and Atmosphere Flagship at CSIRO

 — Professor at James Cook University

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


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