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.
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.
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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!
- 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!
- 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.
- 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.
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.
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.
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.
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.
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
Based on current greenhouse gas emissions, the world is on track for 4C warming by 2100 – well beyond the internationally agreed guardrail of 2C. To keep warming below 2C, we need to either reduce our emissions, or take carbon dioxide out of the atmosphere.
Two papers published today investigate our ability to limit global warming and reverse the impacts of climate change. The first, published in Nature Communications, shows that to limit warming below 2C we will have to remove some carbon from the atmosphere, no matter how strongly we reduce emissions.
The second, in Nature Climate Change, shows that even if we can remove enough CO2 to keep warming below 2C, it would not restore the oceans to the state they were in before we began altering the atmosphere.
How we’re tracking
Currently, we’re at 400 parts per million – rising from 280 ppm before the industrial revolution.
To project future climate change the Intergovernmental Panel on Climate Change (IPCC) uses a range of emissions scenarios called Representative Concentration Pathways (RCPs), based on different economic and energy use assumptions.
In the high scenario, RCP8.5, emissions continue to grow from our present rate of 37 billion tonnes of CO2 per year to about 100 billion tonnes of CO2 in 2100, when atmospheric CO2 levels are projected to be 950 ppm. This scenario assumes little mitigation of our carbon emissions.
In the low scenario, RCP2.6, emissions rise slowly till the end of this decade to about 40 billion tonnes CO2 each year and then start to decline. Amongst the IPCC emission scenarios, only the RCP 2.6 appears capable of limiting warming to below 2C. With RCP 2.6 at the end of the century atmospheric concentrations is about 420 ppm, and only 20 ppm above the present value.
Present emissions are tracking close to the highest scenario (RCP8.5). If we want to keep warming below 2C it requires a substantial reduction in the amount of CO2 released into the atmosphere.
What we have to do
We have two options by which to reduce emissions, the first through reducing the use of fossil fuel energy, and the second through Carbon Dioxide Removal (CDR).
CDR refers to technologies that remove CO2, the primary greenhouse gas, from the atmosphere. Examples include Biomass Energy with Carbon Capture and Storage (BECCS), afforestation (planting trees), adding iron to the ocean, and directly capturing CO2 from the air.
For many CDR technologies the boundary between “climate intervention” (or “geoengineering”) and greenhouse gas mitigation is unclear. However, the goal is the same, enhancing the CO2 current taken up and sequestered by the land and ocean.
Can we just remove carbon?
The first study, led by Thomas Gasser, used results from 11 Earth System Models, in conjunction with a simple carbon-cycle models to simulate different emissions reductions scenarios associated with the low emissions pathway, RCP2.6.
They showed that under all emissions reductions scenarios, even slashing emissions to less than 4 billion tonnes CO2 each year, (greater than a 90% cut in current emissions) is insufficient to limit warming to 2C.
This means that some form of CDR will be required to keep warming at less than 2C. The exact level of CDR required depends very much on the emissions reduction achieved, from 2 billion to 10 billion tonnes of CO2 each year in the most optimistic scenario, to between 25-40 billion tonnes CO2 each year in the lowest emission reduction case. This is equivalent to current total global emissions.
The study also suggests that the requirements for CDR may indeed be even higher if unanticipated natural carbon cycle (positive) feedbacks were to occur. We may desire the ability to remove more carbon from the atmosphere to compensate for these.
The other study, led by Sabine Mathesius, explores whether CDR under high CO2 emissions can achieve a similar environmental outcome to a rapid transition to a low carbon energy use (RCP2.6).
It shows that aggressive CDR can only undo the effect of high emissions (RCP8.5) and return the marine environment to either pre-industrial values or the low emission scenario over thousands of years. The ability to undo the damage caused by high emissions reflects timescale of the ocean carbon cycle. While the upper ocean quickly reaches equilibrium with the atmosphere, the deeper ocean takes millennia to restabilise.
Such irreversibility of the system is an important consequence and the study provides valuable information to consider as we tackle rising CO2 levels. Both studies are theoretical but they provide an important perspective on the ability of mankind to engineer the climate system and undo the effects of high CO2 levels in the atmosphere.
No CDR or suite of CDR technologies exists capable of removing the levels of CO2 at the upper range of what maybe required. This means that, while CDR could aid in limiting global temperatures below 2C, in practice this is not even yet possible, and would not be without risks. This continues to be a very active area of research.
While the focus of both studies explore reversing the environmental changes of rising CO2, the climate system is complex and the possibility that mitigation options like CDR could produce unforeseen impacts is high. While reducing carbon emissions is the safest and preferred path for avoiding dangerous climate change and ocean acidification, it is likely that some CDR will be required to achieve this.
The authors will be one hand for an Author Q&A on Tuesday, August 4 – Andrew between 3 and 4pm AEST and Richard between 5 and 6pm AEST. Post your questions in the comments section below.
We’ve found a cluster of ancient hotheads just east of the Sydney CBD – forgotten relics of an era long passed. And no, it’s not the clientele at Bondi Icebergs on a Sunday afternoon.
Our new ocean explorer, RV Investigator, has discovered four extinct volcanoes 200 kilometres off the coast of Sydney, hidden under almost five kilometres of ocean. The calderas are estimated to be over 50 million years old, putting even the most seasoned Sydney socialites to shame.
Investigator was actually in the area on other business – searching for the nursery grounds of larval lobsters – when it came across the cluster. The ship is constantly mapping the sea floor as it travels, opening up a previously undiscovered and unknown world. Our previous research vessel could only map to 3000 metres, missing important geological features like the calderas. Investigator can map the ocean to any depth (although it’s yet to find James Cameron).
Being the handy little workers we are, we’ve created a 3D flyover of the volcano cluster for your viewing pleasure:
But the volcanoes aren’t the only hot new talking point in Sydney’s far-East. According to the chief scientist for the voyage, UNSW marine biologist Professor Iain Suthers, the team were amazed to discover an eddy off Sydney that was a hotspot for lobster larvae and other tiny critters, at a time of the year when they were not expecting them.
This discovery turned the previous understanding of juvenile commercial fish species on its head.
“We had thought fish only developed in coastal estuaries, and that once larvae were swept out to sea that was end of them. But in fact, these eddies are nursery grounds for commercial fisheries along the east coast of Australia.”
Check out some of the samples the team collected (a few of which wouldn’t look out of place on the dancefloor of the Eastern at 3am):
We can’t wait to hear about more amazing discoveries from the Investigator as it continues its travels. For all the latest on our Marine National Facility, including a virtual tour, check out our website.
Unfortunately, we can’t yet recommend the far-East as a solution to Sydney’s housing crisis. We hear they don’t even have a Gelato Messina out there yet.