Planet Earth Summer 2010

www.planetearth.nerc.ac.uk

Summer 2010

Experiment Earth?

Gases to gases

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Scanning the horizon

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Hunting the last ice sheet

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Bugs, bogs and gravity

Contents

Planet Earth

FEATURES

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12 Giants of the Rewa Head Anacondas and giant otters – experiencing Guyana’s

Summer 2010

biodiversity up close!

15 Scanning the horizon Fifteen things to keep an eye on in environmental science.

18 COVER STORY Experiment Earth?

Finding out what the public thinks of plans for geoengineering.

20 From the sea to the sky Clouds, trace gases and sea-spray – unravelling the climate’s

complexities.

22 L’Aquila earthquake: one year on Responding rapidly to disaster.

24 Gases to gases Isoprene – the many effects of a neglected gas.

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26 Hunting the last ice sheet Scotland’s underwater landscape gives up its secrets.

28 Bugs, bogs and gravity: a new look at methane Using satellites to understand wetlands’ greenhouse gas

emissions.

30 Adapting to a changing climate What can Earth science tell us about the climate?

32 Marine Biological Association 125 years on A century and a quarter of shedding light on the oceans.

NERC scientists: we want to hear from you Planet Earth is always looking for interesting NERC-funded science for articles and news stories. If you want to see your research in the magazine, contact the editors to discuss. Please don’t send in unsolicited articles as we can’t promise to publish them. We look forward to hearing from you.

Planet Earth is the quarterly magazine of the Natural Environment Research Council. It aims to interest a broad readership in the work of NERC. It describes new research programmes, work in progress and completed projects funded by NERC or carried out by NERC staff. Some of this work may not yet have been peer-reviewed. The views expressed in the articles are those of the authors and not necessarily those of NERC unless explicitly stated. Let us know what you think about Planet Earth. Contact the editors for details.

Front cover: Oliver Burston/Photolibrary.com

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Editors: Adele Rackley, 01793 411604, admp@nerc.ac.uk Tom Marshall, 01793 442593, thrs@nerc.ac.uk

Science writer: Tamera Jones, 01793 411561, tane@nerc.ac.uk Design and production: Candy Sorrell, cmso@nerc.ac.uk Available as an e-magazine at: www.nerc.ac.uk/publications/planetearth/

ISSN: 1479-2605

BEYOND CLIMATE CHANGE

Alan Thorpe Chief Executive, NERC

Biodiversity counts T he UN has declared 2010 to be the International Year of Biodiversity – an invitation to celebrate the variety of life on Earth, to value and understand it and, crucially, safeguard it. There are clear signs that human activity is damaging biodiversity, but why is this important, and what can we do about it?

Biodiversity might sound like an abstract term, but it simply means the variety of plant and animal species on our planet, and it embraces every ecosystem from an urban backyard to the deep ocean. We humans are both part of that diversity and dependent on it. One important focus of this international year is to understand the relationship between biodiversity and the health of our ecosystems. We rely on the natural environment for a range of what are known as ‘ecosystem services’: food, fuel and clean water are obvious ones, but just as important are things like regulation of our climate, protection from natural

hazards, breakdown of waste and, not least, aesthetic enjoyment.

We reap undeniable benefits from the services our ecosystem provides, but these are under threat as we slowly convert natural ecosystems to human-dominated ones. The jury’s still out on how far the way we currently manage our ecosystems is damaging biodiversity and what long-term effects this might have, but there is real concern that the damage will not be easy to recover from.

These issues led NERC to make biodiversity one of its seven research themes. Understanding them is vital if we are to continue to enjoy and benefit from environmental services. It is also needed to solve many of the challenges we currently face: food security, renewable energy, environmental protection, climate change and poverty alleviation.

As part of the Living With Environmental Change initiative a UK National Ecosystem Assessment (UK NEA) has been launched, co-chaired by Professors

Robert Watson at Defra and Steve Albon of the Macaulay Institute – see www.lwec.org.uk/activities/ nea for more information. UK NEA involves many government, academic, NGO and private sector institutions and will look at the state and value of the UK’s changing natural environment and ecosystem services in terrestrial, freshwater and marine environments. And a new research programme within NERC’s biodiversity theme aims to provide the basic scientific knowledge that will ultimately underpin policy on the management of UK ecosystems.

Further afield, as you will read in this edition of Planet Earth, NERC is supporting researchers like Rob Pickles whose work in Guyana is highlighting the richness of biodiversity in the South American rainforest, and the particular challenges faced by governments trying to balance development with conservation.

But valuing and nurturing biodiversity are not only the preserve of the scientific

community. This year, 22 May – International Day for Biological Diversity – saw the launch of a series of BioBlitz events around the UK. Many NERC-funded scientists are taking part in these special field surveys, where the public and nature experts work together to record a snapshot of the plant and animal species in an area over a continuous 24-hour period.

Other NERC-supported initiatives taking place this year include the biggest-ever survey of UK ladybirds. Schoolchildren will work with scientists to gather data about these insects, including how the invasive harlequin ladybird is spreading across the country and how native species are responding.

While many paths to protecting the health of our ecosystems are incremental, the questions and challenges facing biodiversity are undeniably large, and large-scale solutions are needed. NERC is in the vanguard of international efforts to focus on biodiversity at a time when the pressures on life on Earth are huge.

Mark Bowler/NPL

Planet Earth Summer 2010

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News Asteroid strike, not volcanoes, spelt the end for the dinosaurs

Peter Arnold Images/Photolibrary.com

The extinction of the dinosaurs and half of all species on Earth was caused by a 15kmwide asteroid slamming into the planet and not by massive volcanic eruptions.

A panel of 41 international experts came to this conclusion after reviewing 30 years’ worth of data on the subject. Their results are published in Science.

The so-called CretaceousTertiary (K-T) mass extinction

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event, which happened around 65 million years ago, wiped out dinosaurs, bird-like pterosaurs, large marine reptiles and twothirds of all species on Earth, ultimately paving the way for mammals to rise to dominance.

Scientists first suggested 30 years ago that an asteroid was behind the mass extinction, after discovering chemical elements originating from meteorites in rocks dating from the transition between the

Cretaceous and Tertiary, sampled all over the world. This idea got further support when researchers then found a 200km-wide impact crater at Chicxulub in Mexico’s Yucatán Peninsula.

The asteroid is believed to have hit the Earth with a force a billion times more powerful than the atom bomb at Hiroshima – enough to blast material into the atmosphere at several kilometres a second and spread dust all over

the world. ‘The impact would have had catastrophic effects including extended darkness, global cooling, acid rain and massive earthquakes,’ says Dr Peter Schulte from the University of Erlangen in Germany, lead author of the study.

Even so, some scientists argue that volcanic activity in India, which lasted around 1.5 million years, was the cause. These eruptions spewed around 1.1 million square kilometres of basalt lava across the Deccan Traps, which would have cooled the atmosphere and caused severe acid rain, spelling the end for much of life on Earth at the time.

To get to the bottom of the conundrum, the scientists sifted through a wealth of information that palaeontologists, geochemists, climate modellers, geophysicists and sedimentologists have built up surrounding the K-T extinction over the last 30 years. The most compelling piece of evidence to support the asteroid theory was an abundance of iridium in geological samples from around the world, deposited at the exact time of the extinction. Iridium is rare in the Earth’s crust, but common in asteroids.

Not only this, but more than 350 samples from the K-T boundary from around the world show a distinctive distribution pattern, with the amount of ejected material related to the distance from the Chicxulub crater at which the sample was taken.

‘It is clear that our paper does not bring discussions to an end, but we made a very strong case built on many scientific disciplines for the Chicxulub impact as the ultimate cause for the K-T mass extinction,’ says Schulte.

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News Bowerbirds copy calls from other species, not neighbours with noises from the surrounding area. Back in the lab, Kelley identified which species they were trying to copy. She also analysed each call’s spectrogram – ‘the visual representation of a sound’.

Although the bowerbird’s own call is an unimpressive hissing sound, the examples Kelley analysed were able to mimic 14 different species of bird, including raptors and songbirds. The bowerbirds’ mimetic portfolio varied across the park. Males were more likely to share the content of their repertoire with neighbours than with other bowerbirds located further afield. ‘This suggests that the birds are copying the sounds of their local environment,’ says Kelley, who published the results in Biology Letters.

The bowerbirds’ interpretation of the pied butcherbird call is a good example. Each individual copied the butcherbirds’ call in a slightly different way. ‘Since

Michael Fogden/OSF

Bowerbirds are better known for their elaborate mating arenas, but they are also accomplished vocal mimics.

Now scientists have discovered that they learn their repertoire directly from other bird species, not from their bowerbird neighbours.

Little is known about why bowerbirds mimic other calls or how they learn and expand their vocal repertoire. ‘Do they learn sounds from other bowerbirds or do they learn them directly from the species being mimicked?’ wondered Laura Kelley, a biologist based at the University of Edinburgh.

As part of her PhD project, Kelley travelled to Queensland in Australia to record the sounds produced by male spotted bowerbirds living in the Taunton National Park. She visited the territories of 19 male bowerbirds and recorded their calls together

butcherbirds have small territories, it seems likely that each bowerbird mimicked the call of a local butcherbird,’ suggests Kelley. On the other hand, bowerbirds across the park produced a fairly similar rendition of the whistling kite.

This is probably because kites have large territories and their call

is likely to be heard by many different bowerbirds.

But we still don’t know whether the birds are copying calls to ward off predators or potential rivals, or perhaps to attract females. ‘We still need to know how bowerbirds use this mimicry,’ Kelley explains.

Bees brave British winters Bumblebees can now be seen all year round, especially in southern England where winterflowering, non-native plants in urban gardens provide the food they need to survive the cold British winter.

Bumblebee colonies in Britain collapse at the end of the summer, when the old queen dies and her daughters go into hibernation before starting their own nests in the spring. But

since the 1990s, there is increasing evidence of a second generation of bees active during winter.

There could be several reasons.

‘Warmer winters are an important factor,’ says Dr Thomas Ings, an ecologist from Queen Mary, University of London. ‘But the availability of food throughout the winter, in the form of exotic, winter-flowering plants in gardens, is crucial.’

To see whether the bees were getting enough food, Ings and his colleague Ralph Stelzer set up several colonies on the roof of their department at Queen Mary.

They used automatic

radio-frequency identification (RFID) technology to tag individual bees and monitor their comings and goings around the colony. They also weighed each bee before and after foraging trips to see how much pollen and nectar they were collecting. ‘We found that the bees were coming back with a good load of nectar in a short time,’ says Ings. Evidently there is enough winter food to keep a healthy bumblebee colony going.

Very few native plants flower during winter, so where are the bees getting their nectar and pollen from? To find out, Ings’ colleague Marc Carlton paid weekly visits to Kew Gardens, where he spotted bumblebees feeding on imported evergreen shrubs such as the

popular mahonia and other winterflowering plants like strawberry trees or honeysuckles.

Ings says: ‘Winter active bumblebee colonies are widespread in southern England, but activity is restricted to urban areas where there are plenty of exotic flowering plants in parks and our gardens.’

Another possible explanation for surging bee activity during winters may be interbreeding between local bumblebees and other subspecies, imported from warmer climates to pollinate tomato and strawberry crops. Some Mediterranean bumblebees are known to produce active colonies during the winter, and they may be passing this ability on to their British cousins.

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News Volcanic ash cloud hits UK When the plume of ash spewing from Iceland’s Eyjafjallajökull volcano brought Europe’s aviation industry to a halt in April, NERC scientists, pilots and technicians swung into action.

The BAe-146 atmospheric research aircraft that NERC maintains alongside the Met Office via the Facility for Airborne Atmospheric Measurements was grounded for a refit, but the necessary instruments were quickly moved onto NERC’s other research aircraft, the Dornier 228 operated by the Airborne Research & Survey Facility out of Gloucester airport.

The Dornier, which is normally used for remote sensing work at comparatively low altitudes, was swiftly airborne and flying out to the plume’s expected location.

Over the next few days it made repeated flights around the plume to gather information on where it was and how it was behaving, while using its sophisticated sensors to keep itself out of danger.

Meanwhile technicians worked round the clock to bring the BAE146 out of refit to help with the task. This is bigger and bettersuited to high-altitude research flights than the Dornier; once it could fly again, researchers used both aircraft to probe the ash plume simultaneously from above and below.

This information provided vital support for government and aviation industry decisions about reopening UK airspace.

Meanwhile, researchers at the National Centre for Atmospheric Science provided guidance and advice on the plume’s likely movement and effects.

This image shows the plume over the UK on 15 April. It was taken by NASA’s Terra satellite and prepared from data received at the NERC-funded Satellite Receiving Station in Dundee.

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News Malaria parasites resist drugs by changing lifecycle resources; both survival and reproduction are important if you want to spread your genes.

Malaria parasites have to find the right balance of replicating and transmissible forms to make sure that they not only survive within their current hosts, but can also spread to new ones.

The new study, published in Proceedings of the Royal Society B, shows for the first time that exposing drug-sensitive strains of the human malaria parasite to low doses of anti-malarial drugs upsets that balance. ‘We think that parasites sensitive to drugs invest in their survival and future transmission by diverting resources from reproduction to replication when exposed to drugs,’ says Reece.

‘It may be that the parasites aren’t responding directly to drugs, but are adjusting their reproduction in response to changes in their numbers. There’s some evidence to suggest the parasite counts to ensure there’s an optimum number within a host,’ she adds.

The findings will have implications for understanding and predicting the spread of antimalarial drug resistance, and the researchers hope this will help inform disease-control strategies.

Sinclair Stammers

Malaria parasites that are sensitive to anti-malarial drugs could evolve and cause more serious illness in people who don’t get treated with drugs, researchers have discovered.

Scientists found that stressing drug-sensitive Plasmodium falciparum parasites by exposing them to low levels of anti-malarial drugs makes them change their behaviour. Rather than putting their energy into developing specialised forms, which can be transmitted to other people by mosquitoes, the parasites replicate within their existing hosts.

‘It’s this replication stage of the parasite’s lifecycle that causes the classic fever and chills symptoms of malaria,’ explains Dr Sarah Reece from the University of Edinburgh, who led the research.

Her team think this change in behaviour is the parasite’s attempt to improve its overall chances of survival. It takes more energy to develop the specialised transmission form of the parasite needed to spread the disease, so sticking to a simple replication – ‘safety in numbers’ – approach to survival is likely to serve the parasite well.

All creatures have to decide how to spend their limited energy

Unreliable diet makes young guppies bolder Young guppies with an Oliver Twist lifestyle grow into intrepid adults. Researchers have found that fish fed at random intervals are bolder and more inquisitive than those reared with a predictable supply of food.

Because ‘guppies reared in unpredictable environments cannot rely on regular food supplies,’ says Dr Ben Chapman, a behavioural ecologist from the University of Leeds, ‘they benefit more from taking risks and actively seek foraging opportunities.’

Chapman wanted to find out why some guppies are bolder than others. ‘There are two main explanations, not mutually exclusive – you either have bold genes, or the behaviour is shaped by the environment,’ he explains.

He and his colleagues investigated the role of early experience in the development of boldness in guppies, which live in rivers teeming with dangerous predators on the Caribbean island of Trinidad.

The team reared two groups of the fish. One was fed at the

same time each day; the other was given food at random times.

When the fish were 56 days old, the team tested their behaviour in three experiments, described in Behavioural Ecology. The guppies raised with an unpredictable food supply were more likely to explore a fish tank set up as a maze and spent less time taking refuge. They also spent less time with shoal mates; as shoaling fish find safety in numbers the amount of time spent out of the group can be used as a measure of an individual’s willingness to take risks.

A third experiment revealed that, while they might be bold, the guppies were not suicidal.

A bird-shaped model was used to create the threat of a lurking predator over the fish tank.

‘This provoked a very powerful response,’ says Chapman. ‘The guppies immediately froze, waiting for the danger to go away.’ This time, however, there was no difference between the two groups. While some of the fish are more motivated to take risks, ‘their main imperative is still to survive,’ says Chapman.

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News Herbicides are not always Successful launch for ESA’s the best solution CryoSat-2 ice mission ESA/S.Corvaja

In April the European Space Agency launched its ice mission CryoSat-2 from the Baikonur cosmodrome in Kazakhstan. The longawaited satellite will measure both the shape and thickness of polar ice with unprecedented accuracy.

The poles are warming up faster than any other region on Earth.

Arctic sea ice is both thinning and receding, Antarctic ice sheets are either disintegrating or at risk of collapse and glaciers are retreating.

But scientists don’t yet know how melting polar ice affects ocean circulation patterns, sea level and the global climate. CryoSat-2’s mission has been designed to help them answer these questions.

The aim is to measure the freeboard – the part of the ice that sits above the waterline. The satellite will use an altimeter to fire pulses of microwave energy down at the ice and record how long it takes for the pulses to return. Scientists will be able to calculate how thick the ice is to the nearest centimetre, by measuring the difference between the time it takes for the echoes to return from the top of ice floes and from the water in cracks in the ice.

Launch day was tense, not least for CryoSat-2’s chief scientist, Professor Duncan Wingham from the Centre for Polar Observation and Modelling at University College London. He first proposed the satellite in 1999, but CryoSat-1 crashed into the northern Arctic Ocean just after lift-off. He immediately set to work persuading ESA that the mission was worthwhile enough to try again, and within four months plans were in place for CryoSat-2. ‘We’re exceptionally proud of this achievement,’ he says.

CryoSat-2’s ability to monitor changes at the poles will surpass the abilities of earlier ESA satellites – its radar has been specifically designed for the task and its orbit will cover much more of the Arctic and Antarctica than has previously been possible.

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When it comes to controlling the aggressive creeping thistle, careful grazing management is more effective than herbicides, say scientists from the Centre for Ecology & Hydrology (CEH).

The creeping thistle (Cirsium arvense) is a tall, fast-growing weed native to Britain and northern European grasslands which, if left unchecked, can smother other grass species and hinder grazing.

Although it’s part of the British flora (and should not be confused with the spear thistle, Scotland’s national flower) the creeping thistle has spread dramatically and is now considered a problem in rural grasslands managed for nature conservation.

The reason behind this spike of thistle growth is probably the recent move to less intensive grassland management, which reduces the amount of fertilisers used and lowers grazing density.

This is good for the ecosystem as a whole but it gives the creeping thistle a perfect environment to spread.

‘Until now people thought that the only way to control it was to use herbicides,’ says Professor James Bullock, an ecologist based at the CEH in Wallingford. But increasing the use of herbicides is not ideal.

So in 2000 Bullock and CEH colleagues at North Wyke Research began to test different control methods at two sites – a lowland pasture in Buckinghamshire grazed by sheep and cattle, and upland grassland in Powys mostly occupied by sheep.

The treatments varied from plot to plot and included different intensities

of grazing, together with the use of herbicides, mowing or combinations of both. ‘We found that, as expected, herbicides did decrease the abundance of the weed and that cutting had little effect,’ says Bullock.

But the most important control method turned out to be the level of grazing. Bullock explains: ‘The largest declines were observed in areas with lenient grazing in spring or autumn,’ that is, plots where animals grazed lightly and the grass was maintained at a moderately tall height. High grass means trouble for the thistle because its yearly shoots won’t grow as well if they’re shaded by other plants. In contrast, where cattle and sheep grazed more heavily the grass is short and the creeping thistle is able to colonise the relatively open areas.

‘Lenient grazing controls the creeping thistle as much as herbicides, with the advantage of being a long-term and environmentally-sustainable solution,’ adds Bullock. ‘We show that making the ecosystem less friendly to the weeds can be just as efficient [as chemicals] in the long run.’

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News X-rays reveal ancient roach’s secret life

Palaeontologists have scanned a 310-million-yearold cockroach fossil with the same X-ray technology used in hospitals to search for tumours, and discovered some intimate details about these ancient creepy crawlies.

Archimylacris eggintoni was 3cm long and lived 310 million years ago in what is now the Midlands, at a time when this region was near the Equator and covered by tropical rainforest. ‘It’s an ancestor of modern cockroaches and praying mantises that lived before the split of the two groups,’ explains Russell Garwood, a palaeontology PhD student based at Imperial College London.

The fossil is embedded in

hard lumps of iron carbonate. ‘The only thing we knew about it was what the creature looked like from above,’ Garwood says.

Garwood is no stranger to this kind of problem: back in August 2009 he uncovered minute details of ancient spider-like creatures, using the Natural History Museum’s CT-scanner to build a 3D image of the fossils. Now he has applied the same principle to the roaches. The X-rays revealed precious details about the wings, mandibles, legs and the antennae that ‘were never seen before in fossil roaches from this age,’ says Garwood.

Archimylacris eggintoni probably ate decaying matter, perhaps dead leaves lying around the forest floor.

With one of its antennae parallel to the body and the other at a high

angle, it could probably sweep them in arc-like movements like modern cockroaches do.

Its legs were long and thin and were articulated in five different places near the end.

This provided extra speed and allowed the roach to run very fast over irregular terrain. It also had claws that would probably have helped it climb trees to lay its eggs or escape from predators.

Thanks to the use of X-ray technology ‘this is now one of the best known roach fossils from this age and we can make educated guesses about how it lived,’ says Garwood. Knowing a prehistoric cockroach had claws and could travel at speed might be a bit too much detail for some.

In brief Marine effects of volcanic ash Scientists from the National Oceanography Centre in Southampton led an expedition to the North Atlantic in May, on board RRS Discovery, to investigate the effects of the recent volcanic eruptions on the biology of the seas around Iceland. The North Atlantic is thought to be lacking in iron, an important nutrient for microscopic phytoplankton which absorb carbon dioxide from the atmosphere. The team hopes to reveal whether the volcanic ash has supplied extra iron to the area, which could have important consequences for the carbon cycle.

Going against the flow Powerful and potentially deadly seaward-flowing rip currents are a major hazard to bathers.

Under a new NERC-funded study, scientists from the University of Plymouth will work with the Royal National Lifeboat Institution to monitor the currents, under a range of wave and tide conditions at Perranporth beach on the north Cornwall coast. The results will feed into a model that aims to forecast when and where potentially dangerous rip currents will occur around the UK. The results will give rescuers a better chance to save lives, with less danger to themselves.

And the winner is...

NERC training fellow Craig Barrie has won an award for his PhD work at the University of Liverpool. The paper – ‘On the growth of colloform textures: a case study of sphalerite from the Galmoy ore body, Ireland’ – of which Craig is primary author, won ‘Best Paper of the Year published by a young author in the Journal of the Geological Society in 2009’.

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News Microbes could point to ancient life on Mars Heat-loving bacteria quickly colonised the shattered rock and boiling water left behind when a huge meteorite smashed into a remote part of what is now Devon Island in Canada’s frozen north, scientists have shown.

The discovery could help in the search for ancient life on Mars, and suggests future missions there should take a look at meteorite impact craters to see if they contain chemical traces that can only be made by living things.

When it struck some 39 million years ago, a meteorite as much as two kilometres across left behind the ‘Haughton impact structure’ – a 23kmwide crater filled with a mass of smashed rock, or ‘breccia’. The force of its impact also heated up the earth, and scalding water circulated around the newlyformed underground fractures and voids in what geologists call a ‘hydrothermal system’.

That system lasted for 10,000 years before finally cooling down.

By that time, heat-loving bacteria Photo by Martin Lipman reproduced with permission from the Canadian Museum of Nature, Ottawa, Canada

The Haughton crater.

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already found in the Earth’s crust had taken up residence, making their living by turning natural sulphate in the hydrothermal waters into sulphides, in the form of iron pyrite and marcasite – a process known as bacterial sulphate reduction.

‘The impact would have fractured and heated up the rock, allowing hot water to begin circulating and making conditions more favourable for these bacteria,’ explains Professor John Parnell, a geologist at the University of Aberdeen and lead author of the paper, published in Geology.

Microscopic laser sulphur isotope analysis at the NERC Isotope Community Support Facility (ICSF), at the Scottish Universities Environmental Research Centre in East Kilbride, provided the key evidence that the sulphides in the hydrothermal system were produced by bacterial activity. The number of neutrons in atoms of an element varies naturally, producing characteristic differences in mass between these different ‘isotopes’ of the same element. The bacteria in

question prefer lighter sulphur, with an atomic weight of 32, to the heavier sulphur 34, each atom of which has two extra neutrons. Both these isotopes occur in natural sulphur-bearing minerals. The sulphides in the hydrothermal system of the impact crater were so markedly enriched in sulphur 32 compared to the starting sulphate that bacterial reduction had to be involved.

‘There’s little chance these sulphides could have been produced by a non-biological process,’ says co-author Dr Adrian Boyce, who manages the ICSF. ‘The isotopic differences between the starting sulphates and the eventual sulphides are just too great.’

The findings suggest traces of life on Mars could be found from the chemical signature left by long-dead organisms. Boyce explains it’s possible to produce miniaturised instruments capable of isotopic analysis in the field, so future Mars landers could be able to investigate the planet’s sulphur-bearing minerals.

CO2 to blame for major sea level rise by 2100 Global sea level is likely to rise by anywhere between 0.6 and 1.6 metres by the end of the century, say scientists. Increased levels of atmospheric carbon dioxide (CO2) and other greenhouse gases would be responsible for 95 per cent of this rise.

In its most recent report, in 2007, the Intergovernmental Panel on Climate Change (IPCC) estimated that sea level would rise by between 18 and 59 centimetres this century.

‘But this estimate is very conservative. The IPCC looked at individual contributions to sealevel rise from thermal expansion of the oceans and glacier melt. We know there’s more to sea-level rise than that,’ explains Dr Svetlana Jevrejeva from the National Oceanography Centre.

In a paper published in Geophysical Research Letters, Jevrejeva and her colleagues describe how they used a statistical model to look at the cumulative effects of both natural changes and man-made changes on 21st-century sea-level rise. ‘Our model uses 300 years’ of sea-level observations from sites across the world. We used it to reproduce past sea level and because it’s such a good match, we’re confident we can use it to estimate future sealevel rise,’ she says.

During the 20th century sea level rose by 18 centimetres, and 25 per cent of this rise was down to natural factors, such as the Sun warming up the oceans or emissions from volcanic eruptions cooling the atmosphere. In contrast, Jevrejeva and her team found that sea-level rise in the 21st century will be dominated by man-made changes in atmospheric greenhouse gases. Natural factors would be responsible for only 5 per cent of the rise.

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News Both images–Oxford Archaeology

Decapitated bodies in Dorset were Vikings Chemical analysis of teeth from decapitated bodies in an ancient burial pit at Ridgeway Hill in Dorset has revealed that the victims were Vikings. They had all suffered wounds inflicted by a sharp weapon to their skulls, jaws and upper spines, and some also had their limbs hacked off.

‘I’m not aware of many other burial sites in this country with this level of slaughter,’ says Dr Jane Evans, head of science-based archaeology at the NERC Isotope Geosciences Laboratory (NIGL) in Keyworth, Nottingham. While Vikings are renowned for their raping and pillaging, ‘here we’ve got real evidence that it was the other way round,’ says Evans.

‘Anglo Saxons rounded up these Vikings and executed them.’

At first archaeologists thought the victims were Iron Age people slaughtered by invading Romans.

But after using carbon-14 to date the remains to between AD910 and AD1030 – the exact time of the Viking invasions – Oxford Archaeology asked Evans and her colleague Carolyn Chenery, also from NIGL, to further analyse the victims. Evans and Chenery used isotopic analysis on ten of the 51 victims to find out what part of the world they came from and what sort of food they grew up on.

Isotopes are different forms of the same chemical element, with slightly different atomic weights.

Proportions of different isotopes of the same elements vary around the world, and scientists can use these differences to unearth a wealth of information on subjects like people’s origins. Because our modern diets include food from all over the world it’s not possible to use the same approach to work out where people come from today.

But in this case, as Evans explains, ‘isotopes from local drinking water and food are fixed into the enamel and dentine of growing teeth. This means we can figure out what sort of food people ate and where they’re likely to have eaten this food.’

Both strontium and oxygen isotopes revealed that the burial pit

victims grew up in countries with a much colder climate than Britain’s.

‘It’s the only site where we’ve done isotopic analysis and demonstrated that the victims are all from outside Britain,’ says Evans.

Surprisingly, the isotopic analysis revealed that the men came from all over Scandinavia – one individual was traced to north of the Arctic Circle. ‘The group could have been an army drawn from a large area,’ suggests Evans. Other injuries, such as a cut to the pelvis, blows to the chest and stomach, as well as defensive injuries to the hands, are also consistent with a major slaughter.

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News Promiscuous females save species from extinction It’s not just males who are known for their promiscuity; females are just as bad. But it turns out that there’s a very good reason for this: promiscuous females could be essential for some species’ survival.

Previous approaches to understanding this behaviour have ignored any benefits to the whole species. Now some researchers think the existence of a chromosome called the sex-ratio distorter, which causes populations to have more females than males, could prevent extinction.

‘The sex-ratio distorter is a set of genes carried on the X chromosome that violates the assumption of equal inheritance,’ explains Professor Nina Wedell from the University of Exeter. These genes make sure that all sperm carrying a Y chromosome are killed and that only female offspring are possible.

‘We figured that if females are limited to one mate and that mate carries the sex-ratio distorter, males would disappear. With no males, the population should eventually die out,’ says Wedell.

To test this idea, Wedell and colleagues from the University of Liverpool describe in Current Biology how they bred 48 groups of the fruit fly Drosophila pseudoobscura, known to carry the sex-ratio distorter chromosome.

They divided the groups into four set-ups; in the first, females were limited to mating with just one male, while in the other three the females could mate with up to six males.

The researchers found that in groups where the females mated with multiple males, the frequency of the sex-ratio distorter chromosome fell rapidly; so much so that by generation nine, the sex-ratio distorter chromosome was much rarer in promiscuous females than in the other females.

But in the ‘monogamous’ group, by the fifteenth generation there were more females than males and 40 per cent of these populations had gone extinct because the males just died out.

In contrast, all 36 promiscuous populations survived.

‘The extinction of populations limited to one mating was clearly down to the sex-ratio bias, which results from the sex-ratio distorter chromosome. Multiple mating by females reduces the frequency of the sex-linked distorter and is likely to do so for many other selfish genetic elements,’ says Wedell. ‘So, the vulnerability of monogamous populations to extinction by sex-ratio distorters may provide a generally overlooked explanation for why promiscuity is so prevalent.’

In brief BioBlitz in the Year of Biodiversity May saw the start of the 2010 BioBlitz season. A bioblitz is a field survey where scientists and the public race against the clock to tickle, tease and net as many species as they can find. They run for at least 24 hours so nocturnal species don’t miss out, and produce a valuable scientific snapshot of an area’s biodiversity. Bioblitzing is great fun and anyone can take part – you can even organise your own – and as 2010 is the Year of Biodiversity it’s a great time to get involved. There are more events through July and August: to find one near you visit: www.bnhc.org.uk/home/bioblitz

Statue ‘DNA finger-printed’ The British Geological Survey has traced stone from a statue of Robert Burns, now in Australia, to its original source in Scotland.

When vandals damaged the 1830s statue, the National Trust of Australia sent samples from the monument to BGS in Edinburgh.

Scientists carried out microscopic studies to ‘fingerprint’ the stone, which turned out to be from near Stirling. The probable original source is now a landfill site, but a near-match was found from Old Drumhead quarry nearby; the owners donated stone for the repairs.

Science of the built environment The high-profile ‘Transition to a Low Carbon Economy’ conference saw NERC joining forces with the Engineering and Physical Sciences Research Centre to show how environmental, physical and engineering sciences can combine to address the challenges of climate change in the urban environment. Among the subjects covered in their session, the extreme effects of heat in towns and cities – the urban heat island effect – was hotly debated; the challenge is to retrofit existing housing stock to address overheating in the summer as well as energy efficiency. For more on the built environment, listen to the Planet Earth online podcast at http://planetearth.nerc.ac.uk/multimedia/story.aspx?id=736 Carbon capture – and reuse?

Scientists from the British Geological Survey will be part of a major new study to investigate techniques for carbon capture and storage (CCS) based on mineralisation. This promising new area of carbon sequestration involves converting CO2 into usable materials – a practical alternative to the more common approach of capturing the gas for storage underground. Certain minerals can react with CO2 to produce a solid carbonate product, which can be stored, used as an aggregate or turned into products such as bricks.

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News Wild gorillas are affected by ecotourism to human diseases. Their immune system is not as hardened as ours, and the communication of something as trivial as a common cold from a human may have the potential to threaten the health of an entire family group. To protect the gorillas, authorities have previously established a minimum distance of seven metres to prevent disease transmission. But is this enough? Michelle Klailova, a PhD student at the University of Stirling, studied a group of gorillas settled at Bai Hokou, Central African Republic, to document their behaviour in response to human presence.

Klailova and her research group followed one silverback male named Makumba for one year and recorded his vocalisations, daily activities and interactions with his 12 family members. She compared these with the size and type of the human group – which included local trackers, scientists and often tourists – and its distance from

Guenter Guni/istockphoto.com

A new review of the effects of ecotourism on western lowland gorillas has shown that the presence of tourists and research teams disturbs the animals and recommends the increase of the minimum observation distance to ten metres.

Ecotourism has become an important source of income for remote African communities living within the natural habitats of famous animal species. Gorilla tourism in particular has boomed with the strong market demand, providing jobs and business opportunities for local people in several African countries. Tempting foreign tourists to enjoy natural parks has also become a strong motivation for governments to invest in conservation, while the presence of researchers, tourists and tourism infrastructure can work as a strong deterrent to poachers.

Ecotourism involves a certain amount of risk for the gorillas, which are known to be vulnerable

the gorillas. Klailova found that the size of the group did have an effect on Makumba and his family.

As the numbers increased, the gorillas spent less time feeding and instead engaged in unfocused, mixed behaviours. ‘As humans move closer he sacrifices part of his feeding time to monitor us, and this cannot be good,’ says Klailova.

The seven-metre minimum distance is based on disease transmission risk. In their American Journal of Primatology paper, Klailova and her team recommend ‘an increase of the minimum observation distance

to ten metres, to incorporate the psychological stressors of close human contact.’ Ideally, the distance should be over 18 metres, at which the gorillas stop reacting to humans but, says Klailova, ‘this is not a realistic goal in dense forests.’ And she believes it’s important to keep the impact of human proximity in perspective.

‘Human factors explain only 10 per cent of the overall variance in the results, which means there are many other important, but yet undetermined, non-human factors that are affecting the gorillas’ behaviour,’ she says.

phytoplankon – which was likely brought to the lake by the wind.

They found six species of bluegreen algae (cyanobacteria), one type of green algae and 32 different bacteria. The only animals living in the area are some small aquatic creatures called rotifers and three species of tardigrade, a group of microscopic invertebrates common in aquatic environments. And that’s it.

‘The list is incredibly limited and it fits on a normal sheet of paper,’ says Hodgson, who reported the findings in Polar Science. ‘If you would apply the same analytic methods to samples from anywhere else, you would get pages and pages listing hundreds of species.’

Hodgson says that the community found in the lakes and soils of the Dufek Massif is a functional ecosystem, but says ‘this is as simple as ecosystems get.’

The Dufek Massif has a harsh climate and is isolated by its remote location, which probably explains its extreme lack of biodiversity. Genetic analysis revealed that the Dufek Massif’s blue-green algae are similar to those in other extreme environments. But the local tardigrade species, the lichen and some bacteria aren’t found anywhere else. The discovery of these endemic species suggests that Antarctica may not be as barren as we thought.

Life at the South Pole Scientists have found a simple but functioning community of bacteria and micro-organisms thriving in the lakes and soils of the Dufek Massif region in Antarctica.

These are the southernmost terrestrial and aquatic ecosystems ever described on Earth, less than 800km from the South Pole.

British Antarctic Survey biologist Dr Dominic Hodgson led a scientific expedition to the site in December 2003. ‘Our aim was to do a bit of traditional descriptive science to find out what is there, and combine this with some of the latest techniques in molecular biology,’ he says.

The team collected samples of the water and the mats of blue-green algae in the lakes and soils. ‘In the lakes the mats are surprisingly abundant covering most of the lake floors, whereas on the soils the mats look like dried lettuce; they grow very large there because there are no grazers eating them,’ says Hodgson. They also photographed a few pinhead-sized lichens, so small and rare that sampling was impossible.

The team didn’t find any evidence of the roundworms or arthropods (invertebrates with external skeletons, like crabs) common in other Antarctic ecosystems, and identified only one diatom shell – a type of

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Giants of the Rewa Head Rob Pickles travelled to a remote stretch of Guyanese rainforest in search of the rare giant otter. He explains how the range of living things he found there surpassed his wildest hopes.

G Top to bottom: giant otter, tapir and dwarf caiman.

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iant anacondas are not the sort of beasts to suffer fools gladly.

Anything that can turn you into a loose, wet bag of shattered bone deserves to be treated with a great deal of respect, which was why we approached this particular polished black coil of muscle and sinew with some trepidation.

‘That is a BIG camoodie Boy!’ Kevin grinned broadly. Ash sized up the snake with a professional eye and thought it looked catchable. ‘Let’s just hope she doesn’t musk; if she musks we’ll stink of anaconda for weeks.

Ryol, you’re tailman’. Ryol grumbled something about always being tailman and perpetually covered in musk and having only just washed his clothes to top it all, but resigned himself to his role.

The anaconda reacted to the weight of four grown men on her with some displeasure and writhed with shocking strength. Ryol hauled on her tail for all he was worth and Niall clamped tight behind the head as her mouth opened

with a husky hiss that smelt of rotten meat and exposed rows of sharp teeth. The jaws were bound, eyes covered, and bit by bit the fight left her. We had a length of rope in the boat and measured her from nose to tail, coming out with a final length of just over 5.5m with a girth of nearly 70cm.

It was a huge snake, a leviathan from another age, but where we were this wasn’t an aberration; we’d already seen five others of similar proportions. We were on the Rewa Head in Guyana’s interior, right in the heart of the Guiana Shield, a huge, ancient dome of rock. The Shield spans Venezuela, the Guianas and part of northern Brazil, and on its back lies the largest single tract of rainforest anywhere in the world, with scores of endemic species found nowhere else. The Rewa river itself is a devil to navigate, cut midway along its length by a string of cataracts and falls requiring heavy portage work to reach its headwaters.

What initially brought us to the middle of Guyana was the species on which my PhD

giants of the rewa head

Anything which can turn you into a loose, wet bag of shattered bone deserves to be treated with a great deal of respect. was based, the giant otter. A bold, gregarious, sinuous creature longer than a man is tall. The giant otter was decimated by the pelt hunting of the last century, and although populations have begun to recover it is still classified as endangered. What we didn’t know was how genetically differentiated populations were, or where migration occurred, if at all. I was interested to see whether any migration was occurring among the Guyanese otters and those of the Orinoco and Amazonian Peru. To find out I needed otter DNA, and to get that I had to find the packs, locate their latrines and scoop up their steaming fresh spraint.

It was the Rewa Head’s uncompromising nature, over which we sweated buckets with

the portaging, which had prevented the hunters from navigating to the headwaters. And it was up here that an enclave of giant otters survived the population crash, and where I’d been told you could witness wildlife flourishing in an almost pre-Columbus state. After hearing those tales, I proposed a trip with good friend and fellow biologist Niall McCann. We realised that basic survey work was urgently needed in the region, and were lucky enough to be put in touch with a man who knew the interior and its wildlife like the back of his hand. Ashley Holland had been working out there for years and he and his team – Ryol, Nando and Kevin – knew the ways of the rivers and the portage lines, were adept at catching caiman and

anacondas, and could also weave a mighty fine basket.

We timed our trip to coincide with the dry season, but that year the weather gods hadn’t been appeased and it rained, heavily and frequently. The river came up, hammock posts squelched and came down and the kitchen was almost washed away. Both Kevin and Ash were nailed by ‘mosquito worm’ and had to pepper themselves with patches of gaffer tape to suffocate the burrowing maggots. It’s fair to say conditions were not ideal, but during our brief 22-day spell in the Rewa Head we had encounters with wildlife that tropical biologists can spend years in the field waiting for.

There is no human disturbance at the Rewa

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GIANTS OF THE REWA HEAD

Head, but people did once come here – the area is not ‘pristine’ in the sense that it has never seen man’s hand. Balata bleeders made the arduous journey up here in the 1970s to tap latex from the rubber trees, and in the forest the rotting remains of a compressor and pipes are all that survive from an abandoned golddredging venture. But the falls are a barrier to all but the bravest, and now the only people to go above Corona Falls are Ash and the odd intrepid twitcher.

As there is no human hunting pressure, game species like tapir, paca and curassow are abundant and unafraid of humans. And with the abundant game comes a healthy predator population. In our camera traps we regularly recorded four species of big cat including puma, while on the river we glimpsed jaguar three times during the expedition. We saw several tapirs bearing rake-marks on their flanks that told of narrow escapes from jaguar or puma attacks, and at the entrance to a paca den we saw the footprints of the enigmatic bush dog.

Crucially, we also found five packs of giant otters and managed to collect the samples I needed. What I found in the genetics was that far from being isolated, the giant otters seemed to use seasonal breakdowns between drainage basins, when floodplains become blurred together, to hop from one

mist nets, camera traps and drift surveys. These included beauties such as the spangled cotinga, crimson topaz, and purple-throated fruitcrow, ten species endemic to the Guianan Shield, and 16 species of raptor, including the awesome and threatened harpy and crested eagles.

The list of ‘giants’ and ‘largest’ species found in the Rewa Head also makes impressive reading: along with the giant otter, largest snake (anaconda) and largest eagle (harpy), we found the goliath bird-eating spider, giant anteater and giant armadillo. More importantly, 14 of the species recorded are listed as globally threatened, yet here several seem to be abundant. We encountered tapirs several times during the drift surveys, and they were the second most common species in the camera traps.

Secondly, the area’s situation is exceptional.

The falls have given the Rewa Head a degree of natural protection from encroachment that has preserved the area so far. It also sits plum between Conservation International’s Upper Essequibo Concession and the proposed Kanuku Mountains Protected Area, forming a natural link between the two areas and together spanning most of the width of southern Guyana.

Thankfully President Jagdeo has realised that Guyana’s forests should be worth more standing than felled, and has offered them up as a global carbon sink. Guyana possesses some of the most carbon-rich forests in South America which, coupled with the high species diversity and the number of plants and animals found only in the Guianan Shield, make these forests an extremely valuable resource – not just to a few conservationists, but to the international community and the Guyanan nation.

There are signs the message is getting through. Last year Norway boldly pledged $250 million to help preserve Guyana’s forests through the UN’s Reducing Emissions from Deforestation and Degradation (REDD) initiative. It is hoped that other nations will follow Norway’s lead and help make Guyana a model of how global carbon offsetting can prevent the remorseless creep of dredgers, drillers and chainsaws.

We are just starting to scratch the surface of the species richness of the Rupununi Basin, of which the Rewa is a tributary. Currently the region’s tally of vertebrate species stands at over 1400, with very

margay. rundi and lot, jagua ce o , a m ter, pu ht: antea Left to rig

tributary to another.

The Orinoco, it seems, is a sort of melting pot between the otter populations of Guyana and northern Peru. Identifying where these routes of migration occur is now the next challenge, to ensure we direct conservation effort at the right spots to keep the populations in contact with each other.

Otters and tapirs and snakes, oh my!

So why is the Rewa Head so special? Firstly, it has high diversity of species, including threatened and charismatic rainforest animals.

Over the expedition we recorded the presence of 33 medium-to-large mammal species, and the total bird count for the area reached 251 from

14 Planet Earth Summer 2010

Thirdly, and most importantly, the region’s valuable natural resources mean it is by no means certain the Rewa Head will remain in its present unsullied state. Gold, oil and timber are all found there, and the Rewa Head itself lies within a logging concession, with felling earmarked to begin within the next few years.

We’ve just entered the ‘Year of Biodiversity’, and although Copenhagen didn’t deliver what was hoped, there is a realisation that attitudes must change, and policy with it, to make it economically worthwhile for poor countries to preserve their natural heritage rather than exploit it. Guyana is the poorest country in South America, so it is under enormous pressure to use its natural resources for economic growth.

little research yet conducted on the fish, reptile and amphibian communities. With further exploration this figure is certain to rise, and this small corner of the Guianan Shield, comprising lowland rainforest, savannah and a unique Caribbean-draining river basin, looks likely to be one of the most species-rich regions in the world. Conservation organisations have recently begun looking in earnest and it seems that the spotlight has, all of a sudden, fallen on Guyana.

More information Rob Pickles is a PhD student at the Institute of Zoology and the University of Kent, studying the population genetics of the giant otter.

Email: robert.pickles@ioz.ac.uk

Many of our current environmental problems could have been avoided with a little forethought. Releasing alien species into new environments, introducing new chemicals without proper testing – the list goes on. And too often, we get to grips with problems only after they’ve become serious. Bill Sutherland plans to change this. He tells Tom Marshall how.

Scanning the horizon W hen conservation scientists meet, they tend to focus on practical problems in the environment right now, and what we could do about them. But when a group of experts from conservation organisations, universities and governments all over the world and from a range of disciplines met in Cambridge late last year, they weren’t talking about anything so concrete.

Instead, they were trying to imagine what the next big problems and opportunities might be.

By the end of the meeting they had settled on 15 issues that they think we should keep an eye on. They range from the possible side-effects of releasing particles into the upper atmosphere to combat climate change to what effect tiny particles of germ-killing silver could have when they get into the sewage system.

The idea isn’t to predict the future, but to highlight areas that may become important in the coming years. Not all of them will. But if even a few do, Bill Sutherland, who organised the event, hopes thinking about them ahead of time will mean we’re better prepared to deal

with them before they get out of hand.

A professor of conservation biology at Cambridge University, Sutherland’s previous projects include collaborating with UK and global policy-makers to identify the key research questions that need answers, and developing evidence-based conservation (see Planet Earth Autumn 2008, pp28-9). But identifying the big risks at the moment is a long way from envisaging what things could be like in a decade’s time.

Sutherland thinks the scientific community needs to spend more time thinking about a wide range of future issues in order to be sensibly prepared. ‘It has struck me for some time that we’re not looking forward sufficiently,’ he says. ‘This means we get taken by surprise by problems we really should have foreseen. An example is biofuels, which were enthusiastically adopted without carefully considering the consequences.’

The idea behind biofuels involves growing plants like oil palms as an energy source. It was championed around the middle of the last decade as a way to reduce our dependency

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on fossil fuels. But Sutherland says the conservation and ecological communities weren’t properly prepared to predict their effects.

Aggressive targets for increasing biofuel use have meant large swathes of alreadyvulnerable ecosystems like tropical rainforests have been destroyed to make way for energy crop plantations. This ecological havoc may outweigh any benefit from burning fewer fossil fuels. This consequence was unintended, but hardly unforeseeable. ‘We failed to anticipate the social, economic, climate change and ecological consequences of actively promoting biofuels,’ Sutherland explains.

‘We often only start thinking seriously about environmental consequences when there’s already a problem, and by then it’s much harder to do something about it,’ he adds. ‘As it is, we’ve adopted biofuels widely and now we’re trying to catch up on the basic research. This is the wrong way round!’

As well as choosing the issues to focus on, the group also discussed how policy-makers and conservationists could respond. In some cases action may be needed right now; in others, all that’s called for at the moment is research to establish whether the risks are real, how serious they are and how we could deal with them. In yet other situations it may be sensible just to wait and see how they develop.

Sutherland and the other participants in the exercise presented their results to Secretary of State for Environment, Food and Rural Affairs Hilary Benn just hours after the end of the workshop – policy-maker engagement in action!

‘Some of the issues he was already familiar with, but many he’d never heard of,’ Sutherland says. ‘This was exactly what we’d been aiming for – a list of issues that are not generally known to most academics and policy-makers. We’ll certainly have missed some things, but we hope this kind of exercise will help alert policymakers and conservation practitioners to issues they might otherwise miss, and we plan to repeat this exercise annually.’

Just one word: microplastics

Growing our own meat

Over the past four decades, global production of plastics has increased twentyfive-fold, and only about 5 per cent of this material has been recycled. Much of the rest has been released into the great outdoors.

And as most plastics take a long time to decay, a lot of it’s still there, making up between 60 and 80 per cent of all litter.

Meat may be tasty, but farming animals to produce it causes all kinds of environmental trouble – and that’s even before you get into ethical considerations and questions of how it affects people’s health. In response, several groups are trying to grow synthetic meat in vats in the lab.

The idea is to take muscle cells from an animal and grow them on a frame that regularly stretches and manipulates them to ‘exercise’ the cells. Eventually we could be tucking into tasty sirloin steaks that have never been near a cow.

Eventually it tends to get washed out to sea, where it is now accumulating in vast stretches of water like the so-called Great Pacific Garbage Patch. Wind and waves gradually break plastic objects down into tiny granules, and these particles of ‘microplastic’ find their way into sand and mud all over the world.

A Dutch sausage maker has developed a way to turn pig stem cells into muscle fibres in a fortnight, though so far the meat produced would cost tens of thousands of dollars per kilo. Progress is accelerating, and there’s a $1m reward for the first to sell tasty synthetic chicken meat to the public by mid-2012. If the technology becomes widespread, it could greatly reduce greenhouse gas emissions from livestock and ease pressure on farmland and fish stocks. But if the number of animals grown for meat dropped quickly, how might other parts of the ecosystem respond? And what are the medical and ethical implications?

We still don’t know what this build-up of plastic particles will do to wildlife, but there’s a serious risk it will prove toxic.

Even if plastic granules themselves aren’t harmful to living things near them, we know they can absorb other pollutants from sea water and pass them on to organisms like sea anemones which live by filtering edible particles out of the water, as well as to fish, birds and other large marine animals that mistake plastic fragments for morsels of food. There’s no sign of the rate of plastic pollution dropping, and scientists don’t know how it could eventually affect the wider environment.

More information Bill Sutherland is Miriam Rothschild Professor of Conservation Biology in the Department of Zoology at the University of Cambridge.

Michael Staudt / VISUM/Still Pictures

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Ashley Cooper/SpecialistStock

Further reading Sutherland et al, A horizon scan of global conservation issues in 2010, Trends in Ecology & Evolution. www.download.cell.com/images/Edimages/Trends/ EcologyEvolution/PIIS0169534709003206.pdf

scanning the horizon

Artificial life

The fifteen issues

Breakthroughs in molecular biology and genetics over the last few years have transformed our understanding of how living things work. In the lab, scientists can now take genetic material from bacteria and combine it with yeast cells to create a new life form that can then live and reproduce on its own.

Microplastic pollution: what could tiny plastic particles do to the environment?

The ability to create bespoke genetic blueprints for new living things isn’t far off.

Craig Venter (below), a pioneer in genomics and artificial life (see Planet Earth Autumn 2009, pp18-19), envisages an explosion of brand new living things designed to meet our needs, whether cleaning up pollution or producing chemicals on demand. He recently hit the headlines by announcing the creation of what he describes as the first synthetic life form – a bacterial cell controlled by DNA that was built in the lab.

Thousands of people breed plants or animals at the moment – what might happen when they gain the ability to design genomes to make their own bespoke organisms?

How could these new creatures affect natural ecosystems? And how can we stop this miraculous technology being put to malicious uses?

Stratospheric aerosols: some scientists want to shoot fine particles into the upper atmosphere to scatter sunlight and slow global warming. But there could be unexpected consequences.

Artificial life: designing our own microbes could let us make chemical compounds on demand, or engineer our own life forms for any number of other purposes. But the new era of bespoke life will also carry profound risks.

Nanosilver in waste water: tiny silver particles designed to kill bacteria are one of nanotechnology’s first mass-market applications. But could they harm natural microbial communities?

Biochar: turning woody biomass into charcoal could let us harvest its energy while keeping its carbon content in solid form, to be returned to the soil and stored there for long periods. But more work is needed on what effects it could have once it’s there.

Mobile-sensing technologies: will mobile sensors and apps become a vital tool for monitoring environmental change?

Deoxygenation of the oceans: global warming tampers with ocean chemistry, and the amount of dissolved oxygen is falling. How could this affect marine ecosystems that are already under pressure from overfishing, ocean acidification and changing temperatures?

Changes in denitrifying bacteria: is global warming affecting the behaviour of bacteria specialised in dealing with nitrogen?

High-latitude volcanism: ice sheets cover many volcanoes near the poles. As they retreat, will the volcanoes get more active? And could this itself accelerate climate change?

Synthetic meat: growing meat in a petri-dish could solve many problems – but what are the economic, ethical and environmental implications?

Invasive Indo-Pacific lionfish are causing havoc in the Caribbean, but could exploiting them for food ultimately benefit endangered edible fish species?

Trans-Arctic dispersal and colonisation: Arctic ice separates the Atlantic from the Pacific – what if it melts?

Large-scale international land acquisitions: countries are buying farmland abroad to secure their food supplies in future. What will the cost be for local environments and economies?

Assisted colonisation: could moving plants and animals to new, more suitable habitats help them cope with climate change? Or is this tantamount to ‘ecological roulette’?

Impact of REDD: The UN’s Reducing Emissions from Deforestation and Forest Degradation in Developing Countries programme (REDD) aims to cut carbon emissions from deforestation. But some fear it could protect forests at the expense of other habitats like savannahs and wetlands.

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Oliver Burston/Photolibrary.com

Experiment Earth?

Geoengineering, which aims to slow down or reverse climate change, is a hot topic. But what do people really think of it? Peter Hurrell describes NERC’s recent efforts to find out.

18 Planet Earth Summer 2010

‘D

oes geoengineering have a part to play in tackling climate change?’

With that question, NERC’s public dialogue on geoengineering got under way in Birmingham. For two Saturdays in early March, 30 members of the public gave up their time to discuss geoengineering technologies and their hopes and fears should these technologies be adopted.

Geoengineering is the name given to a group of ideas that aim to counter or reverse the effects of climate change. Although reducing greenhouse gas emissions is the best way to tackle climate change, it is important to understand what other options are available.

Many of the suggested geoengineering ideas are quite contentious – deliberately trying to change the environment on which we all depend could have serious unexpected consequences. So before we think about investing in research into these technologies,

experiment earth?

Centre), which supports public dialogue across government, we commissioned a team of contractors led by Ipsos Mori to run three sets of dialogue workshops. We also involved scientists, ethicists and environmental and humanitarian charities such as Greenpeace and CAFOD in designing the events, to help our participants think about geoengineering from as many different angles as possible.

The first events were held in Birmingham, and repeated in Cardiff and Cornwall. In each location, thirty members of the public were invited to attend two workshops, which were

aren’t listening or, more importantly, can’t act on what they say. To make sure NERC can respond to participants’ views, the dialogue process has involved one of our theme leaders, a NERC director, and representatives from government departments and agencies, all of whom can influence the direction of future research in this area.

As this article was being written, we were preparing for a final dialogue event at the National Oceanography Centre in Southampton. Participants from the earlier workshops have been invited to come along and talk about what emerged from the dialogue with NERC. Our chief executive and other NERC staff and scientists will be there to discuss geoengineering research with the public and explore their concerns about both the research and deployment of geoengineering. This will give the public a chance to interact with senior decision makers, so they will know their views are being heard.

The results of all of the workshops and the final event will be analysed and combined with other comments received through a web-based survey and open access events at science centres.

These will be used to produce a final report and recommendations for NERC, which will be used when we are thinking about how we will support geoengineering research in future, and how this research should be directed, conducted and communicated.

Public dialogue is an excellent way to find out not just what people think, but why they think it. Running several day-long workshops gave us plenty of time to dig deep into people’s motivations and beliefs, and to discuss a great deal of information about geoengineering.

The whole exercise has also been an excellent learning experience for NERC as it was the first time we have done anything like this.

It was great to see so many people talking openly about environmental science and what it means to them, their families and their way of life. Not every conversation was positive – climate change and geoengineering are not always positive subjects – but the important thing is that conversations were happening. The challenge now is for NERC to listen to what people had to say, and to make sure we build on the results.

People were worried about the safety of some of the ideas.

NERC has been asking the public what they think of the ideas some scientists have proposed.

There are two broad kinds of geoengineering.

The first kind seeks to remove CO2 from the atmosphere, either by using artificial devices to ‘scrub’ CO2 from the air, or by enhancing natural processes that do so – for instance, by fertilising the oceans so that plankton grow faster and absorb more carbon. The second type aims to reflect more sunlight back into space to reduce the temperature of the Earth – a technology called solarradiation management. Both categories have their drawbacks, and we still need to do a lot of research to understand what effects they might have if they were deployed globally.

Public perceptions As you can imagine, the idea of deliberately changing our environment to tackle climate change is something lots of people have an opinion about. These viewpoints are valid hopes and fears that the scientific community should be listening to. But how did we capture such diverse opinions?

We went out and spoke to people. Working with Sciencewise-ERC (Expert Resource

separated by a week in which participants had a chance to do their own research into the subject and think about what they had heard.

At the first events in each city, participants were given some background about climate change to set the context. They then learned about nine geoengineering ideas, from painting roofs white to adding iron to nutrient-starved areas of the ocean, and some of the advantages and disadvantages of each. The second events gave them four possible scenarios to illustrate how geoengineering could be used in future.

They talked about some of the issues raised by the scenarios, such as their social and environmental impact, and any political or economic implications.

So what did we learn from the people at the Birmingham workshops? They felt it was important to tackle the causes of climate change rather than the symptoms, so preferred ideas to remove some CO2 from the atmosphere over those aimed at reducing global temperature by reflecting sunlight back into space. They also preferred more ‘natural’ solutions: afforestation (planting trees) and biochar (using organic matter to produce carbon-rich charcoal, then burying it) were their favourite geoengineering ideas.

People were also worried about the safety of some of the ideas: would captured CO2 leak out of underground storage? Could sulphate particles pumped into the upper atmosphere damage our health? What effect would liming the oceans have on marine life? It is important for NERC to take such concerns into account when considering future research priorities.

Active listening It’s no good asking the public their views if we

More information Peter Hurrell is a member of the NERC Knowledge Exchange team. Email: geoengineering@nerc.ac.uk

Planet Earth Summer 2010

19

From the sea to the sky It is a truth universally acknowledged in environmental science that it is much easier to propose an exciting new hypothesis than it is to prove it. Ken Carslaw and colleagues from the Institute for Climate and Atmospheric Science in Leeds set out to test the 23-year old CLAW hypothesis – and came up with some surprising results.

20 Planet Earth Summer 2010

from the sea to the sky

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f you wanted to identify one theory that launched Earth system science as a major subject of the 21st century it would be CLAW. The hypothesis takes its name from Charlson, Lovelock (of Gaia fame), Andreae and Warren, whose 1987 paper suggested that phytoplankton could help regulate Earth’s climate. Phytoplankton – single-celled algae – emit a gas called dimethylsulphide (DMS) and the authors suggested that DMS forms tiny new particles (or aerosol) in the atmosphere which controls climate by affecting the amount of sunlight reflected by clouds. New aerosol particles from DMS have the potential to increase cloud reflectivity because they are effective cloud condensation nuclei (CCN) – they can increase the number of cloud drops.

But confirming CLAW as an important climate regulation mechanism has proved incredibly challenging. About 1800 articles have been written on the subject, involving studies of plankton biology, gas chemistry, aerosol physics, oceanography, ship cruises and satellite observations, computer model studies and longterm measurements.

When we put seasonally varying emissions of DMS into the model it predicted an almost identical seasonal cycle of aerosol to that observed at Cape Grim. CCN concentrations were about 60 per cent lower in the winter, when seawater DMS concentrations were about five times lower than in summer.

Does this mean we had confirmed CLAW? Not exactly: we had simulated reality but not tested the hypothesis. So we tried turning off the DMS emissions. We expected summertime CCN to fall below the wintertime levels, because lower summer wind speeds meant fewer particles would be coming from sea spray.

But we got surprising results: in many parts of the southern hemisphere summertime CCN remained higher than in wintertime. It turned out that even without DMS lots of aerosol was coming from distant continental regions – from volcanic and pollutant sulphur sources – and this aerosol also peaked in the summer.

The model was telling us that in the modern atmosphere CCN are not as sensitive to changes in DMS as the seasonal variation at Cape Grim would suggest. And when we tested the effect of higher DMS production in a warmer climate we found only a fraction of a per cent change in CCN in the southern hemisphere – not enough to affect climate significantly.

Before we dismiss CLAW it’s worth remembering that climate change throws up surprises, and we may yet see large changes in phytoplankton that are not predicted by current models. For example, disappearing Arctic summer sea-ice will create new DMS sources, which could be pivotal in a region where other aerosol sources are extremely small.

With all this interest in particles produced indirectly by phytoplankton, you might be wondering why we’re not paying more attention to the aerosol we can actually see coming off the oceans as sea spray – doesn’t this have a more direct effect on climate change? The answer would be yes, if the amount of sea-spray aerosol changed over time and caused clouds to get brighter or dimmer. As anyone who has stood on a windy beach will know, the most obvious thing that controls sea spray is the wind speed.

To work out how big an effect wind speed might have we looked at data from the southern hemisphere, where wind speed has increased by about 7 per cent across a wide belt of the

If you wanted to identify one theory that launched Earth system science as a major subject of the 21st century it would be CLAW. Measurements taken at Cape Grim at the remote north-western point of Tasmania appeared to provide compelling support for the hypothesis. They showed that aerosol and DMS varied in unison over the seasons as the abundance of plankton varied. We also know that DMS reacts in the air to form sulphuric acid vapour, which can rapidly join up with water molecules to make new aerosol. But what we didn’t know was how sensitive global CCN are to changes in the emission of DMS from the ocean.

To test the hypothesis we used a new and advanced global model of aerosols. A bit like a weather forecast model, it uses rapidly changing weather patterns to transport aerosols around the world until they are removed by rain a few days, weeks, or even months later. Our challenge was to simulate the aerosol from phytoplankton in great detail on a global scale.

southern oceans since the 1980s. When we fed these winds into our aerosol model we calculated a 22 per cent increase in CCN between 50 and 65°S, and the climate-cooling effect of this extra sea spray turned out to be far larger than anything we calculated due to DMS. In fact, the cooling seems to be large enough to cancel out much of the warming caused by rising CO2 since the 1980s, at least over large parts of the southern hemisphere.

We now think that even small changes in wind speed around the world will be a more important climate regulator than CLAW. But biology is not done yet. Another major shift in our understanding in the last few years is the discovery that a large fraction of the sea spray is not just salt, but also marine life and the organic substances it produces. A teaspoon of surface sea water typically contains a thousand microscopic animals, a hundred thousand microscopic plants, a million bacteria and more than a billion viruses. The level of biological activity in water can be measured by the amount of chlorophyll present – more chlorophyll indicates greater activity. By using satellite measurements of ocean chlorophyll, and global models, we worked out that the world’s oceans emit a whopping 8 million tons of organic material per year, comparable to the mass of organic material emitted into the atmosphere from fossil-fuel burning. In summer, when the biology is most active, organic material can be more important than salt in forming the small CCN particles that most affect clouds.

Organic sea-spray particles are a newly discovered and very direct link between marine life and our climate, and a whole new area of marine research is now under way to pin down the climate effects – the essence of CLAW lives on.

So the next time you go down to the sea, keep in mind that windy days at the beach may be helping to keep our climate cool.

More information Professor Ken Carslaw, Dr Dominick Spracklen and PhD student Matthew Woodhouse work at the Institute for Climate and Atmospheric Science in the School of Earth and Environment at the University of Leeds. More information about their global modelling research is available at www.researchpages.net/glomap.

Much of the work described above was supported through the UK Surface Ocean-Lower Atmosphere Study (SOLAS), a NERC research programme that has involved more than 100 researchers from around 20 different laboratories. www.solas-int.org.

Planet Earth Summer 2010

21

L’Aquila earthquake: one year on When a powerful earthquake struck Italy’s Abruzzo region last year, UK Earth scientists were on the scene quickly to help authorities understand what had happened. Richard Phillips describes what they found.

Max Wilkinson AP/Press Association Images

Richard Phillips

22 Planet Earth Summer 2010

L’Aquila earthquake: one year on

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t 3.32am on 6 April 2009, a magnitude Mw6.3 earthquake hit the mountainous region of Abruzzo in central Italy. An event that lasted just a few seconds would result in a final death toll of 307, with 70,000 people made homeless and much of the historic medieval town of L’Aquila and the villages around it damaged or destroyed. In economic terms, this brief event cost Italy an estimated €4 billion.

Unfortunately, the people of Italy are no strangers to such natural hazards; since the mid-14th century it is estimated that there have been around 300,000 earthquake-related fatalities throughout the country. In Abruzzo alone, earthquakes have killed up to 40,000 people since an event in 1703 that razed L’Aquila, followed by a devastating quake near Avezzano in 1915. Despite these distressing figures, large magnitude earthquakes are relatively infrequent in Italy. Given this, what can Italian civil authorities do to reduce the long-term earthquake risk in their country, and how can they limit the cost of reconstruction? To answer these questions, it is useful to examine what happened in L’Aquila.

Initial response Five hours after the main earthquake, a group of UK scientists began preparing to head out to Abruzzo. In close collaboration with Italian scientists, we aimed to help find the ground rupture produced by the earthquake and to monitor any subsequent change in ground deformation using advanced laser technology.

Coordination of the relief effort was impressive and rapid. Within a short time, the authorities had deployed 12,000 rescue and support workers from across the country. ‘Tent cities’ surrounded the main towns, emergency plans for the construction of new housing were rapidly initiated and, across the region, hundreds of geologists and geophysicists were working to answer the questions of what, why and where next?

Watching such awful events on television does not quite prepare one for the reality of the situation. Although the local people were generally calm and were coping as best they could, the tension and distress were palpable. I was particularly struck by a question asked of me by a member of staff at a hotel where I had previously stayed. Seeing us at work, she approached and asked directly, ‘Why didn’t you tell us? Why L’Aquila?’ These were important questions, and ones I could not easily answer. It may be that precise earthquake prediction is simply not possible,

but why did the earthquake happen here and how can we mitigate the effects of future events?

Why L’Aquila?

The Abruzzo region lies at the centre of the Apennine mountain chain. This jagged spine of Italy runs from the northwest down to Calabria in the south. The Apennines exist due to the continued collision between the Eurasian and African plates. Over the last two million years though, the Apennines have essentially been pulled apart by a set of complex tectonic events.

The ongoing result is a system of active faults running parallel to the range and which are responsible for the region’s earthquakes. Many of these events are recorded in prominent changes in land level along fault lines. These linear features, called bedrock scarps, are common around L’Aquila signifying a long history of seismic activity: since the 14th century, the town has been hit by eight major events. The worst occurred in 1703, killing an estimated 5000 people and devastating the town.

Few scientists were surprised by such an event in this region, but some were puzzled by the location of the ground rupture. None of the obvious bedrock scarps appeared to have been affected and much attention was placed on scouring local faults for the signature of a fresh earthquake rupture. With the help of satellite remote sensing provided by the University of Oxford and the Istituto Nazionale di Geofisica e Vulcanologia, attention returned to a fault near the village of Paganica, east of L’Aquila.

Initially, surface evidence of the earthquake was limited to ground cracks, sometimes just a few millimetres wide that snaked through the village and across fields. Following more detailed investigation, geologists discovered ground ruptures displaying up to 15cm of vertical movement. Despite the lack of dramatic surface rupture, this fault was responsible for the devastation in surrounding towns, of which L’Aquila and the village of Onna fared the worst.

One year on What became evident following the L’Aquila event is that the earthquake ruptured almost entirely through gravel-rich soil. The nearby village of Onna was worst hit because it is built on this soft subsurface, which amplifies ground shaking. Using laser technology, termed LiDAR, or Light Detection and Ranging, the UK consortium was able to periodically monitor the rupture’s development over the four months following the event. Following

formation of the original rupture, a further 1.5cm of vertical movement was recorded over 124 days after the earthquake.

This small displacement may seem inconsequential, but it is enough to concern engineers. This was exemplified by the decision to recommission a ruptured 40-inch-diameter high-pressure water pipe, supplying drinking water to the L’Aquila valley. Following the earthquake, continued movement across the fault resulted in the pipe rupturing for a second time. Such events clearly hamper efforts to mitigate further damage during any relief effort.

Away from the fault, however, reconstruction could continue unhindered by continued ground movement. Within eight months, 4500 new dwellings had been designed, planned and built on eight sites, providing accommodation for 12,000 displaced people. Each dwelling followed strict building regulations to ensure that they would withstand similar earthquakes. These regulations were strongly enforced because, despite a building code in place since 1981, new buildings such as the main hospital and a university housing block had been severely damaged during the earthquake.

Should we rely on a similar post-event relief effort next time? Clearly, the answer has to be no; the economic and human cost is too high and could be significantly reduced.

Governments need to ensure that they employ detailed long-term seismic hazard assessments before defining, and enforcing, strict building codes. And for those who live in tectonically active regions a comprehensive education programme is needed, to make sure that the public is aware and prepared for future hazards. Such assessment and mitigation plans are already in place in Italy, Japan and California; we should ensure that poorer countries, such as Haiti, receive the support they need to do the same.

MORE INFORMATION Dr Richard Phillips is a lecturer in the Institute of Geophysics and Tectonics, School of Earth and Environment, at the University of Leeds.

Email: r.j.phillips@leeds.ac.uk The UK LiDAR survey team included: Dr Ken McCaffrey and Max Wilkinson (University of Durham), Dr Gerald Roberts (UCL-Birkbeck), Professor Patience Cowie (University of Edinburgh) and Dr Richard Phillips (University of Leeds).

FURTHER READING Walters, RJ, Elliott, JR, D’Agostino, N, England, PC, Hunstad, I, Jackson, JA, Parsons, B, Phillips, RJ, Roberts, G (2009). The 2009 L’Aquila earthquake (central Italy): a source mechanism and implications for seismic hazard, Geophysical Research Letters, 36, doi:10.1029/2009GL039337.

Planet Earth Summer 2010

23

Gases to gases Isoprene produced at sea has profound effects on our climate and on ocean ecosystems, but until recently it’s received limited attention. Dan Exton explains how this neglected gas is at last getting the notice it deserves.

Photolibrary.com

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gases to gases

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or hundreds of millions of years, photosynthesis – the process plants use to turn sunlight into energy – has played a key role in controlling our climate. In fact, the gases exchanged with the atmosphere during photosynthesis are fundamental for life on Earth. The evolution of life was stimulated by a build-up of oxygen in the atmosphere, while the removal of carbon dioxide helped maintain the planet’s temperature. Often overlooked, though, are the numerous trace gases involved in this process, which have major effects on climate because of their reactivity.

Over the past few decades, interest in these trace gases has grown enormously, with scientists investigating the roles they play in regulating climate, and the benefits organisms get from producing them. This interest spans both terrestrial and marine sciences.

Terrestrial scientists have focused on the hydrocarbon isoprene, which is the most abundant trace gas produced by vascular plants like trees and grasses. Emissions of isoprene to the atmosphere are roughly equal to those of methane, a powerful greenhouse gas (see pp28-9). Ocean scientists have focused on the sulphur compound dimethyl sulphide (DMS), the main sources of which are marine plankton and seaweeds.

But while DMS is almost exclusively produced in the marine environment, isoprene is made by many organisms that photosynthesise both on land and at sea. Yet few studies have been carried out on isoprene in the world’s oceans.

Isoprene is particularly important because it has significant effects on the climate. Being highly volatile, it oxidises rapidly in the atmosphere. Its presence leads to an increase of ozone in the lower atmosphere, which is itself a greenhouse gas and responsible for many health complaints in humans. Isoprene also increases the lifetime of methane in the atmosphere, prolonging its damaging greenhouse effect.

So it’s important that we do more research, to understand how isoprene is produced, the role it plays in marine communities and ecosystems, and how environmental change will affect its future production.

Taking the heat?

Until recently, we thought some of isoprene’s harmful effects would be negated by its ability to stimulate the formation of aerosols, which cause clouds to form (see pp20-21). The presence of isoprene was thought to help reflect the sun’s rays with a layer of cloud, cooling the planet and reducing global warming. But new evidence suggests the opposite – that isoprene

actually inhibits cloud formation and so will only make global warming more severe. If this is right, the effect of isoprene in the atmosphere above the oceans could work against that of DMS, which is known to drive cloud formation.

Another angle to the isoprene story is the benefits to the organisms that produce it.

Essentially, making isoprene strengthens cell membranes and increases their thermotolerance – it protects them from damage caused by high temperatures. The effect can be so dramatic that in some cases isoprene has been shown to increase the maximum temperature plants can tolerate by 7.5°C. But this protective role could mean isoprene production increases as the planet warms in the future. So not only could isoprene be responsible for an important proportion of atmospheric change, it could also drive a positive feedback pattern – a vicious circle of higher temperatures causing more isoprene emissions, which in turn help drive temperatures even higher.

We are also looking at isoprene’s role as an antioxidant, protecting plant cells from damage by harmful molecules including ozone and hydrogen peroxide. Although this is often thought to be an evolutionary coincidence, which came about as a side-effect of developing thermotolerance, the benefits to isopreneproducing organisms are still important.

Isoprene has also been shown to act as a signal to other living things, for example deterring herbivores from feeding on certain isopreneproducing plants.

What little work has been done on isoprene in marine systems has been largely restricted to sources in the open ocean, which dominate in terms of area but not in rates of productivity. Yet emerging evidence suggests that isoprene plays a major role in the world’s oceans, particularly in coastal habitats.

By the sea shore These important ecosystems could represent a vastly underestimated source of isoprene. At the University of Essex, we have been improving our knowledge of isoprene in marine coastal systems, where photosynthetic activity is generally much higher than in the open ocean due to a higher biomass of marine organisms. As part of a NERC-funded project, we are investigating the isoprene production rates of important habitats like salt marshes and different organisms like seaweeds, seagrasses and corals – in many cases for the first time. Using specially designed gastight equipment we are looking at how these organisms respond to a range of conditions, particularly varying temperature and light, and beginning to understand how the environment

controls isoprene production and the different amounts organisms produce.

Coasts and estuaries often have a wide range of environmental conditions in a relatively small space and, particularly in temperate zones, these can change significantly by day and by season. This means they can provide valuable information about how ecosystems may respond to environmental change, and in turn how the production of isoprene may change under future climates. To make the most of this we’re carrying out a year-long field survey to monitor isoprene production along a UK estuary. This builds on a recent Essex-led study which found that diverse microbes living there consumed significant amount of isoprene making it an important energy source for coastal bacteria. This also suggests that algae are actually producing far more isoprene than we are detecting in the atmosphere.

Alongside these studies, a recent technological advance is enabling us to analyse isoprene production from marine sources in real time. To do this, NERC-funded scientists at Essex have modified a sensor normally used in atmospheric and terrestrial studies. It uses a chemical reaction to measure isoprene, so it can take marine measurements of the gas ten times a second. This important development promises to allow research to be carried out in much greater detail and will help address many unanswered questions.

Alongside existing research into isoprene in marine systems, projects like these should soon give us a much better understanding of the connection between isoprene production and environmental change. This will be a critical step in evaluating the role and potential feedback of isoprene in future climates on planet Earth. It will also help us judge how big an impact marine isoprene could have relative to both terrestrial isoprene and marine DMS. When we know all this we’ll be much better placed to understand the balance of power of these trace gases across the planet as a whole.

More information Dan Exton is a PhD student at the University of Essex’s Algal Research Group.

Email: daexto@essex.ac.uk Further reading Acuña Alvarez, L, Exton, DA, Suggett, DJ, Timmis, KN and McGenity, TJ (2009). Characterization of marine isoprene-degrading communities.

Environmental Microbiology 11, 3280-3291.

Exton, DA, Smith, DJ, McGenity, TJ, Steinke, M, Hills, A and Suggett, DJ. (In press). Application of a Fast Isoprene Sensor (FIS) for measuring isoprene production from marine samples. Limnology and Oceanography: Methods

Planet Earth Summer 2010

25

Hunting the last ice sheet

Rannach Moor.

The seabed around Scotland is giving up the secrets of the last ice age. Kate McIntyre and John Howe explain how.

S

cotland has been subject to repeated glaciations over the past 2 million years – the evidence is all around in the wild and rugged landscape, the ice-carved glens and dramatic sea lochs. Yet the landscape beneath the sea is now also beginning to reveal further clues as to the extent and dynamics of the British Ice Sheet.

We are re-evaluating the extent and effect of the last northern ice cap to have occurred in the UK. The ice cap existed in Scotland during a cold period termed the Younger Dryas. This rapid cooling at the end of the last glaciation may have been caused by a temporary slowing of ocean circulation, or even perhaps by a meteorite impact in North America that led to a decrease in global temperature. Such short, cold climatic events are called stadials; the Younger Dryas stadial occurred between 12,800 and 11,500 years ago – very recently, geologically speaking!

During this time a large ice cap covered much of western Scotland. Modelling studies and onshore fieldwork in the area have established the assumed limits of the ice cap.

And with the development of more advanced geophysical techniques, we are now examining the offshore marine record. Studying the marine environment has many advantages; the main one is its ability to preserve ancient climates, both in the shape of the seabed and in the layers of sediments that accumulate there.

My PhD project, funded by NERC and based at the Scottish Association for Marine Science (SAMS) in Oban, investigates the offshore records of Scotland’s last ice cap.

This involves examining sediment records, and mapping the underwater limits of the ice

26 Planet Earth Summer 2010

cap by collecting and interpreting multibeam sonar data. Multibeam systems use multiple beams of sound directed at the seabed to build an accurate acoustic map of the underwater landscape. We used SAMS’ new Reson Seabat multibeam system to carry out the mapping from research vessel R/V Calanus.

Fjords – better known in Scotland as sea lochs – are carved into the landscape by glaciers, and act as outlet conduits for ice and water draining seaward from their main ice caps. This means they often preserve moraines – ridges of gravel, sand and rock left behind as the glacier retreats – within their basins. We can identify these moraines on the seabed by multibeam mapping.

Loch Linnhe is the south-westerly end of the Great Glen Fault which cuts across Scotland to the Moray Firth on the east coast. During past ice ages, the loch was a major outlet for glaciers from the Rannoch Moor area, where ice built up in the initial stages of development.

Our recent multibeam survey of Loch Linnhe discovered moraines that suggest that the Younger Dryas glacier may have advanced significantly further down the loch than was previously thought from onshore field mapping evidence.

Further evidence for a more southerly limit is contained in sediments from the sea floor. We have found very heavily compacted sediment in a core sample taken much further south than the mapped onshore limit of the glacier.

The only way for the sediment to become so compacted is by the crushing weight of ice passing over the top of it, so the glacier must have reached at least as far south as the position of this core.

Several moraines associated with an ice-scoured rocky outcrop.

The glacier seems to have retreated in several stages, each being marked by a recessional moraine deposited at the front of the glacier when it paused in its long retreat, or even returned briefly to advancing. This stepped pattern of retreat has also been observed in the Summer Isles region in north-west Scotland.

Here, a multibeam survey by the British Geological Survey in 2005 revealed a similar pattern of recessional moraines preserved on the seabed.

Mapping beneath the waves As well as the Loch Linnhe research, my fieldwork has involved sea-floor mapping in the Sound of Sleat and further out to sea, west of the Isle of Muck. Scotland’s west coast, with its many lochs, glens, mountains and islands, is well known for its outstanding natural beauty, and it has been a huge privilege to have the opportunity to carry out my fieldwork in this area. The Linnhe survey was carried out in

hunting the last ice sheet

David Woods/istockphoto.com

Recessional moraines preserved on the seabed of Loch Linnhe.

February, but we were blessed with beautiful weather and calm conditions. The Calanus made her way up and down the loch at a sedate surveying speed of three to four knots, offering alternate views of the snowy mountain peaks of Glencoe to the north-east and the raised shorelines around the Firth of Lorne and the island of Lismore to the south-west.

Meanwhile the multibeam transducers beneath the boat were pinging away, picking up the returning echoes of sound and translating them into a beautiful seafloor image on our onboard computer screen. It was fascinating to watch as features such as moraines and ice-scoured rocky outcrops appeared on the screen, revealing a hitherto unseen complex underwater landscape. Later in the Sound of Sleat, we weren’t so lucky – a storm blew up in the middle of our first day’s survey and we were forced to batten down the hatches and make our way back to Mallaig harbour through the mountainous waves. Fortunately we had already

mapped a large moraine outside the mouth of Loch Hourn, demonstrating that, as in Loch Linnhe, the ice here extended further seawards than the onshore evidence suggests.

The raging weather trapped us in the harbour for the rest of the week, but the following Monday dawned blue and sunny. We steamed out past the islands of Rum, Eigg and Muck and surveyed the Muck Deep – a long, narrow depression in the seabed carved out during earlier ice ages, when ice sheets much bigger than the Younger Dryas ice cap covered vast areas of North America and Europe. At 320 metres, the Muck Deep is one of the deepest points on the UK continental shelf (the area of shallow sea surrounding land, which rarely exceeds 200 metres in depth). The survey was carried out over three days of silky seas and utter tranquillity; we were even briefly joined by a pod of bottlenose dolphins which swam around and underneath the bow of the boat, much to the delight of crew and scientists alike.

At present there is considerable debate over the extent and timing of the short-lived Younger Dryas event. The stadial interrupted a period of warming at the end of the last ice age, plunging the northern hemisphere back into glacial climate conditions. The big question that is vexing glaciologists is whether or not the Younger Dryas ice cap grew from nothing after the main ice sheet disintegrated. Numerical models predict that it could have done – but this disagrees with the recent offshore evidence, which shows that the glens and sea lochs of western Scotland were filled with glaciers to some extent even during the warm period before the stadial.

Questions like these might seem a little esoteric and only of interest to academics, but modern and recent climate models are being used to predict climatic change over short timescales measured in decades. To test these models, it is vital that we have as much information as possible about how climate has changed in the past and how these changes have affected our environment. If the models can accurately ‘predict’ climate change that we know has already occurred, then we can have much more confidence in predictions they make about the future. Studies like ours provide the evidence for past climate change, against which ice-sheet and climate models ​ can be tested.

More information Kate McIntyre is a PhD student and Dr John Howe a lecturer in Marine Geology at the Scottish Association for Marine Science.

Email: kate.mcintyre@sams.ac.uk or john.howe@sams.ac.uk

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a new look at methane

A peat bog on Fairfield in the Lake District National Park.

Wetlands are the largest source of methane but until now we have not understood how changes in these natural emissions affect concentrations of methane in the atmosphere.

Paul Palmer and Anthony Bloom describe how they used satellite observations to reveal new insights into this greenhouse gas.

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M

ethane is the poor cousin of carbon dioxide (CO2), often mentioned in passing when the subject of greenhouse gases is raised but rarely the focus of discussion. But should it be? Sure, there is roughly 200 times more CO2 in the atmosphere than methane, largely because methane is removed from the atmosphere relatively quickly, with an ‘atmospheric lifetime’ of 9 years. But as a greenhouse gas methane is about 25 times more potent than the same amount of CO2.

Calculations from the 2007 Intergovernmental Panel on Climate Change (IPCC) report showed that over a 20-year period methane has as much impact on the climate as CO2.

The oxidation of methane in the atmosphere also helps to determine the concentration of ozone in the lower levels of the atmosphere, so methane has a significant indirect effect on climate too. Elevated levels of ozone are linked to human respiratory illnesses and falling agricultural crop yields, both of which have measurable economic consequences. So it is clear that controlling emissions of methane is important for mitigating global warming in the short term and as part of a more comprehensive strategy to reduce greenhouse gas emissions.

Between 1984 and 2009, the amount of methane in the atmosphere increased by 10 per cent – 165 parts per billion (ppb). While this increase was fairly steady up until 2006,

in 2007 methane concentrations started to rise almost simultaneously at all latitudes.

What changed over this period? Scientists have suggested a number of hypotheses based on sparse surface data but did not reach any firm conclusions.

Our project went into space for a closer look. We used methane observations from the SCIAMACHY satellite instrument, which measures how solar radiation is absorbed by the atmosphere. These observations contain information about the processes that release and destroy methane and about the winds that blow the gas around the atmosphere. But there is nothing in the satellite measurement that can tell us which surface processes cause the atmospheric variations. Other gases showed no evidence of large changes in the manmade sources of methane or in the surface or atmospheric processes that consume methane (known as ‘sinks’). This led us to study changes in the wetland source of methane.

Wetlands – bogs, fens and swamps for example – are the single largest source of methane. Methane is produced by microbes under anaerobic conditions and is consumed by other microbes under aerobic conditions – a wonderful example of how some of the smallest components of the climate system help determine the evolution of the Earth’s climate. The net amount of methane emitted by wetlands is determined by temperature,

Ashley Cooper/Global Warming Images

Bugs, bogs and gravity:

BUGS, BOGS AND GRAVITY

water level and organic carbon content, with temperature generally playing a larger role at high latitudes and water availability being more significant at low latitudes. We used output from a numerical weather model for surface temperature changes, but for changes in water level we once again looked to space, this time the GRACE satellites. These can measure very small changes in gravity, some of which can be related to changes in groundwater level.

Our next step was to develop a mathematical model to investigate how atmospheric methane changed with temperature and water levels between 2003 and 2005, combining the weather model output and satellite data with information on global wetland emissions from the IPCC report. When we tested our model over the period 2003-2007 we found that global wetland emissions increased steadily, peaking in 2007. This was mainly due to increased emissions at mid-high northern latitudes, with the large increase in 2007 due to warming at high northern latitudes and increased precipitation in the tropics – a result that agreed with the analysis of the surface data.

So, what next? Our analysis has shown that even moderate changes in warming at high northern latitudes or precipitation at low latitudes can lead to a substantial release of methane into the atmosphere. Other (unpublished) work suggests that currently emissions of methane from wetlands are not growing, which means we have not yet reached the warming necessary for a self-sustained runaway increase in emissions. Reaching this level of warming would eventually result in the release of a huge amount of methane currently trapped underneath the permafrost.

How close we are to this point, or indeed whether it exists, is uncertain. But the combination of surface and satellite

measurements has been important. Detailed surface data can be used to advance our understanding of how individual wetlands respond to changes in climate. Satellite data can be used to relate this information to the globe, effectively mapping these large vulnerable regions to help develop and monitor land-use policy. Such policy lies at the centre of managing wetland emissions but there is currently no consensus as to what an effective long-term strategy would be. What is clear is that integrated research activities like these are fundamental to the development of sensible approaches to limiting climate change caused by methane.

More information Paul Palmer is Professor of Quantitative Earth Observation in the School of GeoSciences at the University of Edinburgh. Email: pip@ed.ac.uk.

Anthony Bloom is a NERC PhD student. Email: a.a.bloom@sms.ed.ac.uk.

The NERC-funded MethaneNet project promotes integrative research activities. www.methanenet.org.uk Further reading Bloom, AA, Palmer, PI, Fraser, A, Reay, DS and Frankenberg, C (2010) Large-scale controls of methanogenesis inferred from methane and gravity spaceborne data. Science 327, 322-5.

Nigel Hawtin

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Adapting to a changing climate W The British Geological Survey’s climate change programme is just two years old, but is already tackling some of the toughest questions to emerge from climate science. Mike Ellis explains how.

IODP scientists onboard JOIDES Resolution celebrate the collection of the longest-ever core by the hydraulic Advanced Piston Corer, from 458.4 metres below the sea floor.

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hat will the climate – and indeed the weather – be like in the future? And how will our environment, all of it – urban, rural, chemical, physical, biological – respond to climate change? These two fundamental questions are still not resolved, but the answers will lie at the very heart of any strategy for adapting to climate change.

Palaeoclimate and palaeoenvironments Future climates are difficult to predict. Not only is the system chaotic but we don’t yet know all the feedbacks that affect it. Feedback means a knock-on effect – when the impact of one change effectively increases, or decreases, the effect of further change. The rapid loss of Arctic ice in 2007, and faster rise in sea levels than models had predicted, show that our poor understanding of these feedbacks limits our ability to see into the future.

But to look ahead it is sometimes useful first to look back. Our geological past offers a unique insight into how the Earth responds to different conditions. Ocean and lake-sediment cores are beginning to reveal, in startling detail, how the Earth system responds to relatively sudden changes. For example, close to 55 million years ago, an amount of carbon

dioxide (CO2) roughly equivalent to our current known reserves of fossil fuel was injected into the atmosphere – a massive change by any standards. Incredibly, some of the cores BGS is looking at have such high resolution that scientists can interpret how the Earth responded almost year by year.

One of the most significant climate changes in Earth’s history occurred about 450,000 years ago (the so-called mid-Pleistocene transition), when climate cycles changed from around 40,000 to 100,000 years. No one knows why, and until we understand these sorts of changes we can’t hope to predict future climate with any certainty. To find answers, BGS scientists are taking part in the first ever expedition to the Bering Sea by the Integrated Ocean Drilling Program (IODP). This lets us use ocean sediment cores to compare changes in the Arctic ocean environment to global climate change, to tackle questions of how the Earth system works as a system. Information in the cores will show us how closely Earth’s environmental response is linked to changes in climate, and how the system varies during and after these rapid changes.

The last time the Earth’s atmosphere had a CO2 concentration of 365-415 parts per million was during the Pliocene, around 3 million years ago, and the planet was on average 3-4°C warmer (probably a lot more in the northern hemisphere). If man-made emissions continue at present rates we will reach the higher of these levels soon after 2020. So we have to find out – and soon – how the environment differed when average global temperature was this high. One way of doing this is by looking at sea-surface temperatures in the Pliocene. BGS is a partner in the USGS PRISM climate project, one goal of which is to find clues to sea-surface temperatures in the ratio of heavy to light oxygen isotopes preserved in clam and planktic fossils. This will help show how heat was transported through the world’s oceans, and it’s vital that we understand how this part of the system operated in the warmer Pliocene world if we are heading in the same direction.

BGS will use this data in its new

adapting to a changing climate

Flooding in Cockermouth, Cumbria, in November 2009. The scale of events like these depends on the climate and the sensitivity of the specific environment. BGS models will assess such sensitivity to future climates.

palaeoclimate modelling initiative, which links the state of the Earth system during the Pliocene to that of the Anthropocene, the name being given to the potentially newest geological period – an epoch born of human influence on our home planet. New palaeoclimate models are being developed, for example, to investigate the role of modern land-use in determining what the climate might have looked like had it not been for the development of civilizations. And we are investigating the role of oceanic heat transport in providing thresholds or tipping points in a changing climate.

The environment is a dynamic system as we have seen, and we are considering it from every angle. Feedbacks to the climate system revolve around the fate of stored carbon, whether in soils, methane sources or permafrost. BGS is looking at all of these, investigating carbon cycling in soils and biomass, changes in carbon pools in UK soils, and the stability of methane in wet and frozen environments. (We look at carbon capture and storage too – ways of capturing CO2 as it is generated and storing it away from the atmosphere.) Based on new evidence, BGS scientists have also developed new ideas about how the British ice sheet behaved during the last ice age, and the relative chronology of the advance and retreat of glaciers. This will give us a better understanding of ice-sheet dynamics in a warming world, which in turn will provide further insight into the dynamics of the retreating Greenland ice sheet.

All of these efforts will reduce our uncertainty about future climates and the state

of the Earth’s system in a warmer and rapidly changing climate. But this is only half of the problem. The other half may be more complex, and will involve a much broader range of disciplines.

Modelling the environmental impact Lots of work has gone into modelling future climates, but relatively little into how the environment as a system will respond.

Translating probabilities of climate change into probabilities of environmental impact is one of the most significant challenges ahead for the climate change community. Scientists from BGS are collaborating with colleagues from a range of other disciplines to develop a model to assess environmental sensitivity to climate change – ESC. Environments do not behave in a linear way and environmental responses (in terms of frequency of landslides, say, or the form that a water channel wants to take, or changes to an ecosystem within that channel) are extraordinarily difficult to predict. They are subject to many complex processes and we are only beginning to understand how these processes are linked.

And it isn’t only the extreme events that may be important – a greater number of apparently less significant events could make a considerable difference to the conditions in which extreme events take place. The ESC model will link the dynamics of these processes – hillslope and cliff stability, ground and surface water flow, sediment transport, channel form, ecological processes, coastal processes, and many more.

Rather than reinvent wheels, we aim to combine

existing models on a common platform, designing new components where necessary.

An ESC model will provide a quantitative assessment of how a specific environment will respond to a different distribution of weather events, at a scale that will be directly useful to people who need to make decisions about urban and rural adaptation strategies.

The application of an ESC model would not be possible without the long history of monitoring and evaluating Britain’s environment by BGS and its sister organisation CEH – the Centre for Ecology & Hydrology.

Such long-term studies are crucial for providing the initial conditions for an ESC model, because unlike climate modelling, the ESC model cannot assume that the environmental system starts in equilibrium.

One of the main drivers of environmental change over hundreds to thousands of years is base-level change – the combination of shifts in sea and land levels. We can see from studies of earlier ice sheets that land sinks and rises with glacial movement, while the existence of organisms that are sensitive to salinity tell us about changes in sea level. Base level and climate set the pace for erosion, and BGS is reassessing erosion across the UK and feeding this information into dynamic models to assess the sensitivity of specific environments to climate change.

The BGS climate change programme has existed in its present guise for a little more than two years but already has ties to more than 20 UK universities as well as sister agencies, CEH, the British Antarctic Survey and the National Oceanographic Centre in Southampton. The few aspects touched on here don’t do justice to the very broad scope of the programme, a scope that will certainly expand because, ultimately, we are driven by the need to serve the national interest in the best way possible. So BGS will continue to be responsive to the fundamental questions about climate change that emerge from the scientific community and wider society.

More information Mike Ellis is head of climate science at BGS. www.bgs.ac.uk/research/climatechange Pliocene Research Interpretation and Synoptic Mapping (PRISM) http://geology.er.usgs.gov/eespteam/prism NERC Isotope Geosciences Laboratory www.bgs.ac.uk/nigl/Climate_RatesChange.html Further reading US National Research Council (Washington DC) (2010) Landscapes on the Edge: New horizons for research on Earth’s surface.

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ESA

MBA scientists were some of the first to use satellites to study ocean phytoplankton populations.

Marine Biological Association

125 years on In September last year, some of the top names in the marine world gathered in the Fishmongers’ Hall in London to celebrate the Marine Biological Association’s 125th anniversary. Guy Baker looks at some of the work that has led to this success.

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he unassuming limestone building on the eastern side of Plymouth Hoe is a research laboratory, behind whose walls some of the UK’s most eminent marine biologists have wrestled with the pressing science questions of their day for more than a century. The laboratory is home to the Marine Biological Association of the UK (MBA) which was formed by the Royal Society in 1884, primarily to investigate the decline of fish stocks. Newly elected president, TH Huxley, didn’t believe the ocean’s resources could be dented by the technology of the time.

But his view wasn’t shared by Ray Lankester, the MBA’s first elected secretary, who was very concerned about the effects of the increasing numbers of fish being landed on UK shores.

More than a century on we know that fish stocks are being severely depleted by human activities, and the challenges that now face the oceans and societies across the globe are bigger and more complex than either Huxley or Lankester could have imagined. Large cod, tuna and skate – all abundant in the North Sea in the early part of the 20th century – are now reduced to between 5 and 10 per cent of levels 100 years ago, or are locally extinct.

Protection of areas of the seabed and spawning populations of fish is a large part of the solution, and the work of MBA scientists has kept the organisation at the forefront of such challenges.

The MBA’s long-term records of fish and zooplankton in the western English Channel have been invaluable for showing environmental change over decades and act as a baseline against which the effects of human activities can be measured. MBA scientists Frederick Russell and Alan Southward were responsible for a key piece of research on marine systems.

They looked at zooplankton data and the changes that were observed over roughly 50-year time periods from a predominance of pilchards in the English Channel to one of herrings. This work was supported by records of taxation on fish landings and temperature records going back to the mid-17th century, which showed that pilchards were landed during warm periods and herrings during cold.

The ‘Russell Cycle’ introduced the idea that climate changes follow a roughly ten-year cycle and that these cycles drive periodic changes in marine ecosystems.

Backed by such painstaking long-term studies, MBA scientists have been responsible for some truly groundbreaking scientific achievements. In the early 1950s Alan Hodgkin and Andrew Huxley revealed the chemical mechanism of nerve transmission through their work on the giant nerve fibre found in squid. The scientists’ combination of theoretical and experimental work led to Nobel prizes for Hodgkin, Huxley and John Eccles in 1963.

marine biological association

Alan Southward was one of the most influential British marine biologists of his generation. His work with Dennis Crisp was among the first to show the effects of climate on marine ecosystems; it provided a baseline against which recent responses to global warming have been compared and continues to form the foundation for much current MBA research on environmental change. The Marine Biodiversity and Climate Change (MarClim) project has built on Southward’s legacy, continuing and expanding the MBA’s longterm records of selected rocky-shore species whose abundances were known to be linked to fluctuations in climatic conditions. By studying the distribution of a variety of invertebrates such as limpets and topshells around Britain and Ireland, and using historical data to provide baselines for previous warm and cool periods, MBA researchers found that southern species

Species based in the south of Britain are moving northwards and eastwards at up to 50km per decade. are moving northwards and eastwards at up to 50km per decade – far exceeding the global average of 6.1km per decade on land.

Always at the forefront of marine research, in the 1970s and 1980s MBA scientists were some of the first to use satellites to study ocean phytoplankton populations. They produced the first satellite images of blooms of coccolithophores in the Atlantic Ocean. This

alga is now making headlines for its absorption of carbon dioxide from the oceans, and 40 years on MBA researchers are trying to understand exactly how ocean plankton – and particularly the coccolithophores – absorb CO2 and produce calcium carbonate. They are developing new tools and techniques to measure the state of plankton in real time in the sea, and to track the changes of past plankton populations.

Another continuing line of research began in the 1980s, when MBA scientists noticed bizarre abnormalities in marine animals living in and around estuaries and at coastal sites where there was lots of boating and shipping activity. In particular, ‘imposex’ – the imposition of male sexual characteristics on females – was seen in certain types of molluscs. The worst affected was the dog whelk, Nucella lapillus, which was rapidly becoming unable to reproduce and in some areas had even become extinct. The scientists identified tin-based antifouling paints as the culprit. The most active ingredient in these paints was tributyl tin – TBT – which the researchers showed to have endocrinedisrupting properties, interfering with the

MBA scientists found that antifouling paints were damaging marine life.

whelks’ hormone production. Populations of other molluscs such as clams, Scrobicularia plana, were found to be in decline at TBTpolluted sites too. This and related research led to a ban on the use of TBT-based paints on smaller vessels in the UK in 1987 and to International Maritime Organisation (IMO) recommendations for a similar measure for the global commercial fleet from 2008 onward.

This line of work continues to contribute to national and regional perspectives on human impacts on marine environments, and to map pollution hotspots.

The MBA is also looking at how marine animals’ environments influence the way they search for food. Since food in the oceans is often sparsely distributed predators must cover huge areas. Electronic tagging and tracking of animals as diverse as penguins, basking sharks and tuna has revealed that the movements of predators correspond to Lévy flight patterns – rather than moving through their environment in a random manner they employ a strategy which maximises their chances of finding their thinly spread prey.

Over 125 years the MBA has established an international reputation for excellent, independent research into all aspects of marine and environmental science. It advises Government and has an innovative education and public outreach programme.

The organisation is a founder member of the Plymouth Marine Sciences Partnership (PMSP) which is the largest regional cluster of expertise in marine sciences, education, engineering and technology in Britain and one of the largest in Europe. Climate change, ocean acidification and pollution, the combination of biological, geological and chemical processes and the many other pressures the oceans endure are now exercising the minds of our scientists, and some of the UK’s best young researchers will have the formative experiences of their scientific careers in the limestone building on Plymouth Hoe. The next 125 years are likely to be even more demanding than the last but no less rewarding.

More information Guy Baker is communications officer at the Marine Biological Association. E-mail: guba@mba.ac.uk The MBA is a learned society and welcomes new members: visit www.mba.ac.uk/membership.php.

The Association’s research programme is supported by grant-in-aid funding from NERC.

KLJ Photographic/Alamy

More information about the MBA’s 125-year celebrations can be found at: www.mba.ac.uk/125years.php and for more information on PMSP visit www.pmsp.org.uk

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