Constantine Alexander's Journal

Global climate on verge of multi-decadal change

RAPID moorings are being deployed. Credit: The National Oceanography Centre.

A study, published in Nature, proves that ocean circulation is the link between weather and decadal scale climatic change. These findings, by scientists from the National Oceanography Centre (NOC) and the University of Southampton, imply that the global climate is on the verge of a broad-scale change that could last for a number of decades. This study is based on observational evidence of the link between ocean circulation and the decadal variability of sea surface temperatures in the Atlantic Ocean.

The change to the new set of climatic conditions is associated with a cooling of the Atlantic, and is likely to bring drier summers in Britain and Ireland, accelerated sea-level rise along the northeast coast of the United States, and drought in the developing countries of the Sahel region. Since this new climatic phase could be half a degree cooler, it may well offer a brief reprise from the rise of global temperatures, as well as resulting in fewer hurricanes hitting the United States.

Lead author, Dr Gerard McCarthy, from the NOC, said: "Sea-surface temperatures in the Atlantic vary between warm and cold over time-scales of many decades. These variations have been shown to influence temperature, rainfall, drought and even the frequency of hurricanes in many regions of the world. This decadal variability, called the Atlantic Multi-decadal Oscillation (AMO), is a notable feature of the Atlantic Ocean and the climate of the regions it influences."

These climatic phases, referred to as positive or negative AMO's, are the result of the movement of heat northwards by a system of ocean currents. This movement of heat changes the temperature of the sea surface, which has a profound impact on climate on timescales of 20-30 years. The strength of these currents is determined by the same atmospheric conditions that control the position of the jet stream. Negative AMO's occur when the currents are weaker and so less heat is carried northwards towards Europe from the tropics. Therefore multi-decadal climatic changes, such as the one impending, can be predicted by measuring the strength of ocean currents using a network of sensors called the RAPID array. These sensors have been collecting data on the flow rate of the Atlantic meridonal overturning circulation (AMOC) for a decade.

Dr David Smeed, from the NOC and lead scientist of the RAPID project, adds: "The observations of AMOC from the RAPID array, over the past ten years, show that it is declining. As a result, we expect the AMO is moving to a negative phase, which will result in cooler surface waters. This is consistent with observations of temperature in the North Atlantic."

Since the RAPID array has only been collecting data for last ten years, a longer data set was needed to prove the link between ocean circulation and slow climate variations. Therefore this study instead used 100 years of sea level data, maintained by the National Oceanography Centre's permanent service for mean sea level. Models of ocean currents based on this data were used to predict how much heat would be transported around the ocean, and the impact this would have on the sea surface temperature in key locations.

Co-author Dr Ivan Haigh, lecturer in coastal oceanography at the University of Southampton, said: "By reconstructing ocean circulation over the last 100 years from tide gauges that measure sea level at the coast, we have been able to show, for the first time, observational evidence of the link between ocean circulation and the AMO."

Professor Ian Wright, Director of Science and Technology at the NOC said: "This work clearly emphasizes the critical role of the ocean in driving decadal-scale changes in climate that has very real human consequences, as well as the continued need for long-term measurement of ocean change at critical sites around the world"

The sustained observations of the Atlantic overturning circulation, provided by the RAPID array, is a major strategic investment by the Natural Environment Research Council (NERC) and US funding bodies, to observe key climate variables.

Citation: Gerard D. McCarthy, Ivan D. Haigh, Joël J.-M. Hirschi, Jeremy P. Grist, David A. Smeed; Ocean impact on decadal Atlantic climate variability revealed by sea-level observations; Nature, 2015; 521 (7553): 508 DOI: 10.1038/nature14491.

Contact: Holly Peacock
National Oceanography Centre, UK

 

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Little-known quake, tsunami hazards lurk offshore of Southern California

Satellite picture of the Channel Islands off the coast of Southern California. New research into the little known, fault-riddled, undersea landscape off of Southern California and northern Baja California has revealed more worrisome details about a tectonic train wreck in the Earth's crust with the potential for magnitude 7.9 to 8.0 earthquakes. Credit: NASA.

While their attention may be inland on the San Andreas Fault, residents of coastal Southern California could be surprised by very large earthquakes - and even tsunamis - from several major faults that lie offshore, a new study finds.

The latest research into the little known, fault-riddled, undersea landscape off of Southern California and northern Baja California has revealed more worrisome details about a tectonic train wreck in the Earth's crust with the potential for magnitude 7.9 to 8.0 earthquakes. The new study supports the likelihood that these vertical fault zones have displaced the seafloor in the past, which means they could send out tsunami-generating pulses towards the nearby coastal mega-city of Los Angeles and neighboring San Diego.

"We're dealing with continental collision," said geologist Mark Legg of Legg Geophysical in Huntington Beach, California, regarding the cause of the offshore danger. "That's fundamental. That's why we have this mess of a complicated logjam."

Legg is the lead author of the new analysis accepted for publication in the Journal of Geophysical Research: Earth Surface, a journal of the American Geophysical Union. He is also one of a handful of geologists who have been trying for decades to piece together the complicated picture of what lies beyond Southern California's famous beaches.

The logjam Legg referred to is composed of blocks of the Earth's crust caught in the ongoing tectonic battle between the North American tectonic plate and the Pacific plate. The blocks are wedged together all the way from the San Andreas Fault on the east, to the edge of the continental shelf on the west, from 150 to 200 kilometers (90 to 125 miles) offshore. These chunks of crust get squeezed and rotated as the Pacific plate slides northwest, away from California, relative to the North American plate. The mostly underwater part of this region is called the California Continental Borderland, and includes the Channel Islands.

By combining older seafloor data and digital seismic data from earthquakes along with 4,500 kilometers (2,796 miles) of new seafloor depth measurements, or bathymetry, collected in 2010, Legg and his colleagues were able to take a closer look at the structure of two of the larger seafloor faults in the Borderland: the Santa Cruz-Catalina Ridge Fault and the Ferrelo Fault. What they were searching for are signs, like those seen along the San Andreas, that indicate how much the faults have slipped over time and whether some of that slippage caused some of the seafloor to thrust upwards.

What they found along the Santa Cruz-Catalina Ridge Fault are ridges, valleys and other clear signs that the fragmented, blocky crust has been lifted upward, while also slipping sideways like the plates along the San Andreas Fault do. Further out to sea, the Ferrelo Fault zone showed thrust faulting - which is an upwards movement of one side of the fault. The vertical movement means that blocks of crust are being compressed as well as sliding horizontally relative to each other-what Legg describes as "transpression."

Compression comes from the blocks of the Borderland being dragged northwest, but then slamming into the roots of the Transverse Ranges - which are east-west running mountains north and west of Los Angeles. In fact, the logjam has helped build the Transverse Ranges, Legg explained.

This map shows the California Borderland and its major tectonic features, as well as the locations of earthquakes greater than Magnitude 5.5. The dashed box shows the area of the new study. Large arrows show relative plate motion for the Pacific-North America fault boundary. The abbreviations stand for the following: BP = Banning Pass, CH = Chino Hills, CP = Cajon Pass, LA = Los Angeles, PS = Palm Springs, V = Ventura; ESC = Santa Cruz Basin; ESCBZ = East Santa Cruz Basin Fault Zone; SCI = Santa Catalina Island; SCL = San Clemente Island; SMB = Santa Monica Basin; SNI = San Nicolas Island. Credit: Credit: Mark Legg.

"The Transverse Ranges rose quickly, like a mini Himalaya," Legg said.

The real Himalaya arose from a tectonic-plate collision in which the crumpled crust on both sides piled up into fast-growing, steep mountains rather than getting pushed down into Earth's mantle as happens at some plate boundaries.

As Southern California's pile-up continues, the plate movements that build up seismic stress on the San Andreas are also putting stress on the long Santa Cruz-Catalina Ridge and Ferrelo Faults. And there is no reason to believe that those faults and others in the Borderlands can't rupture in the same manner as the San Andreas, said Legg.

"Such large faults could even have the potential of a magnitude 8 quake," said geologist Christopher Sorlien of the University of California at Santa Barbara, who is not a co-author on the new paper.

"This continental shelf off California is not like other continental shelves - like in the Eastern U.S.," said Sorlien.

Whereas most continental shelves are about twice as wide and inactive, like that off the U.S. Atlantic coast, the California continental shelf is very narrow and is dominated by active faults and tectonics. In fact, it's unlike most continental shelves in the world, he said. It's also one of the least well mapped and understood. "It's essentially terra incognita."

"This is one of the only parts of the continental shelf of the 48 contiguous states that didn't have complete ... high-resolution bathymetry years ago," Sorlien said.

And that's why getting a better handle on the hazards posed by the Borderland's undersea faults has been long in coming and slow to catch on, even among earth scientists, he said.

NOAA was working on complete high-resolution bathymetry of the U.S. Exclusive Economic Zone - the waters within 200 miles of shore - until the budget was cut, said Legg. That left out Southern California and left researchers like himself using whatever bits and pieces of smaller surveys to assemble a picture of what's going on in the Borderland, he explained.

"We've got high resolution maps of the surface of Mars," Legg said, "yet we still don't have decent bathymetry for our own backyard."

Citation: Mark Legg, Monica D. Kohler, Natsumi Shintaku and Dayanthie Weeraratnee; High-resolution mapping of two large-scale transpressional fault zones in the California Continental Borderland: Santa Cruz-Catalina Ridge and Ferrelo faults; Journal of Geophysical Research (2015); DOI: 10.1002/2014JF003322.

Contact: Nanci Bompey
American Geophysical Union

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Biodiversity offset policy: dangers that must be avoided

By Science for Environment Policy

Biodiversity offset policies may inadvertently incentivise behaviours which actually accelerate biodiversity loss, new research has found. The study's authors identify four ways this can occur and make recommendations for prevention.

Biodiversity is declining worldwide. Much of this is the result of developments, from roads to buildings, which destroy and fragment habitat. 'Biodiversity offset schemes' — in which the developer creates, restores or protects habitats elsewhere — are intended to compensate for these negative effects, with the ultimate aim of achieving 'no net loss' of biodiversity.

However, concerns have been raised regarding these schemes, with some studies showing that biodiversity is likely to be lost because the schemes are ineffectual, or that sites do not have long-term protection and therefore are only likely to achieve no net loss initially, and are then later degraded. For this study, researchers investigated the possibility that biodiversity offset policies, even if well designed and properly implemented, might result in 'perverse incentives', i.e. encouraging behaviours which actually result in a net loss of biodiversity. The authors identified incentives for:

1. Entrenching or exacerbating baseline declines. In order to assess whether no net loss of biodiversity is achieved, a baseline must be set from which to measure biodiversity losses and gains. At the time when a development occurs, net biodiversity drops; the aim is that over time, as the offset site develops, this should return to the baseline. However, the outcomes for conservation could differ drastically, depending on where the baseline is set, and how it changes over time. If, for example, background levels of biodiversity are assumed to be declining rapidly, and this is used as the 'business as usual' baseline, then fewer gains are needed from the offset site. This is because the offset is only required to maintain the trajectory of declining baseline across the impact and offset sites collectively. This can then create a self-fulfilling prophecy: if biodiversity is assumed to be declining, offsetting does not need to achieve as much, and thus can entrench these assumed declines.
2. Winding back other conservation actions. Other conservation initiatives essentially make offsetting schemes more difficult and expensive for the developer. If conservation programmes succeed in reducing biodiversity loss, this raises the baseline from which to measure biodiversity gains, making it more difficult to attain no net loss of biodiversity by offsetting. If a decision maker has an interest in facilitating development, there may be an incentive to advocate the use of overly steep declining baselines, as this reduces the required biodiversity gains and thus the expenses associated with offsetting activities. The offset policy then 'locks in' these declines. In addition, designating land as protected reserves also means it is not available for use as an offset site. Similarly, if conservation actions reduce the threats to populations of a threatened species, these can no longer be targeted under offset schemes as 'averted losses' — no loss is being averted if the species is not threatened and therefore not expected to decline.
3. Crowding-out of conservation volunteerism. Volunteering has boosted conservation worldwide, and in some cases, volunteers have been invited to assist in offset actions. In a case in Australia, the outcomes of volunteer work to restore a park were used retrospectively as an offset for an urban development, but it was unclear whether the volunteers knew the conservation gains they were achieving were allowing equivalent destruction of biodiversity elsewhere. If offsetting projects redirect volunteer efforts from other conservation projects, the volunteers are then contributing to actions that would not have otherwise been required. This would also reduce the gains those other projects would have made, therefore exacerbating biodiversity loss.
4. False public confidence in environmental outcomes due to marketing offset actions as gains. Conservation gains resulting from offset actions are often described as conservation gains in their own right. For example, the proposed UK biodiversity offset scheme was described by the government as "an exciting opportunity to look at how we can improve the environment as well as grow the economy". However, this is not the case. Offset schemes, even if they fully achieve their goal of 'no net loss', are not positive improvements but entirely neutral in terms of biodiversity gains. Describing offset schemes in this way could result in the public perception that offset activities are gains in their own right. This could then reduce public pressure on governments to invest in conservation, further eroding biodiversity and again representing a net loss.

To avoid these perverse incentives researchers recommend that the process to set the baseline should reviewed every 10 years. However, as detailed in the first point, if schemes fail to achieve no net loss, the baselines may then be recalculated as steeper declines. This will mean that fewer gains are required from offset schemes, and biodiversity declines further. They also recommend that calculations for baselines, and the wider biodiversity declines from which they are drawn, should all be stated clearly. It may be useful to use a flat baseline, which would assume no background declines over time. Finally, they recommend better education and outreach regarding offset policies, that would help explain how offset activities are not 'conservation gains' but are making up for losses elsewhere and are thus neutral at best.

Readers interested in a comprehensive review of the technical and legal issues and possible solutions relating to biodiversity offsets are referred to a recent review supported by the European Commission.

Citation: Gordon, A., Bull, J. W., Wilcox, C. & Maron, M. (2015). Perverse incentives risk undermining biodiversity offset policies. Journal of Applied Ecology. 52: 532–537. DOI: 10.1111/1365-2664.12398.

Contact: Ascelin Gordon

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Drones can be used to study birds without affecting their behaviour

Drones — unmanned aerial vehicles — may be used in close proximity to bird populations without causing disturbance, finds a new study. Drones hold the potential to monitor species and areas that are difficult to reach. The authors advise that, when used with caution, drones could become a valuable tool in the monitoring of species, particularly in protected areas.

Drones are increasingly used in ecological research to study wildlife, because of their ability to reach inaccessible populations and habitats. Despite the increasing use of drones to observe bird populations, there are no ethical guidelines for the potential impact of drones on animal welfare.

In this study the authors aimed to determine the impact that drones have on the behaviour of birds, in order to provide guidelines for the continued use of drones in this type of research.

During March and April 2014, the researchers used quadricopter drones, each with four spinning blades, to approach three different bird populations: mallard ducks (Anas platyrhynchos) in a zoo, and flamingos (Phoenicopterus roseus) and common greenshanks (Tringa nebularia) in their natural habitat. The birds were approached at different speeds (2 metres per second, 4 m/s, 6 m/s and 8 m/s) and angles (20°, 30°, 60° and 90°) using three different coloured drones (white, black and blue), and their responses noted according to three categories (no reaction; small amount of movement; or, flying away).

The researchers found that in 80% of the experiments they were able to fly a drone to within four metres of a bird population without noticing any visible signs of behavioural change. The speed at which the drone approached, the colour of the drone used and repeated approaches did not appear to affect bird behaviour in a significant way.

However, the angle at which the drone approached the birds did have a marked impact on how they behaved. When approached from directly above (90° angle) all the bird populations either moved, or flew away from the drone, and the authors hypothesise that this was due to the drone being associated with a bird of prey.

The findings are good news for future studies that plan to use drones to record data from wildlife populations; however, the authors urge caution. They note that different species will react differently to the presence of drones, and that animals can still experience stress without showing a change in behaviour. In addition, different drones vary in size and noise generation, and these factors could also have an impact on wildlife.

Following their study, the researchers advise that: drones should always be launched more than 100 m from bird populations; that the distance a population is approached from is adjusted according to the species being observed; and that drones are never used to approach populations at a 90° angle.

Citation: Vas, E., Lescroël, A., Duriez, O., Boguszewski, G. & Grémillet, D. (2015). Approaching birds with drones: first experiments and ethical guidelines. Biology Letters, 11(2), 20140754. DOI: 10.1098/rsbl.2014.0754.

Contact: David Gremillet

Scientists use unmanned aerial vehicle to study gray whales from above

A rare opportunity to study how the environment limits the growth of a recovered population of large whales.

A gray whale and her calft migrate north along the California coast on their way to summer feeding grounds in the Arctic. Credit: NOAA.

One recent spring day, John Durban, a NOAA Fisheries marine mammal biologist, stood on the California coast and launched an unmanned aerial vehicle into the air. The hexacopter--so called because it has six helicopter-type rotors--zipped over the ocean and hovered above a gray whale mother and her calf. The pair was migrating north from their calving grounds off Baja California, Mexico, to their summer feeding grounds in the Arctic.

NOAA Fisheries scientists have stood at this point of land each year for the past 22 years, binoculars in hand, to estimate the number of gray whale calves born each year. That's an important step in monitoring the ups and downs of the population. But scientists would like to understand more completely what causes those ups and downs, and this year, with the addition of the hexacopter, they hope to find out.

As the hubcap-sized hexacopter hovered high above the whales it shot straight-down photos from a digital camera mounted in its belly. In addition to a camera, the hexacopter also carried a very precise pressure altimeter, allowing scientists to know the exact altitude at which each image was taken. Later in the lab, they would analyze the images, measuring the length and girth of the whales to within a few centimeters.

"We can't put a gray whale on a scale, but we can use aerial images to analyze their body condition--basically, how fat or skinny they are," Durban said.

Durban and co-pilot Holly Fearnbach, also a NOAA Fisheries scientist, would ultimately capture images of more than 60 cow/calf pairs.

The image on the left shows a very skinny female gray whale and her calf just visible beneath the water's surface. This whale may or may not have sufficient energy reserves to make it thousands of miles to the Arctic while also nursing her calf. In contrast, the female on the right is quite robust, and has a high likelihood of successfully rearing her calf. Scientists are using an unmanned aerial vehicle to produce very precise overhead images of gray whales, then analyzing the images to understand how environmental conditions affect the health of adult females and ultimately the reproductive success of the population. Credit: NOAA.

A Long and Difficult Journey

The amount of fat on a gray whale cow is critical to the survival of her calf. Gray whales don't feed during most of their months-long migration, and while the mothers are fasting, they're also nursing their fast-growing calves. Therefore they need a lot of blubber to fuel the journey to their Arctic feeding grounds.

How much blubber they're carrying depends in part on conditions in the Arctic the summer before. If the whales had access to plentiful prey, the cows will have sufficient fat on them, and most calves will likely survive the journey. But if conditions weren't favorable, fewer calves will be born, and fewer still will make it.

"By studying the body condition of females, we hope to connect the dots between conditions in the Arctic one year and calf production the next," Durban said. "Ultimately, we're trying to understand how environmental conditions affect the reproductive success of the population."

Throughout the study, scientists kept the hexacopter at least 120 feet above the whales. When used at this altitude by trained scientists, unmanned aerial vehicles offer a safe and non-invasive way to collect important data on marine mammals and other protected species.

NOAA Fisheries biologist John Durban brings the hexacopter in for a landing as colleague Holly Fernbach prepares to catch it. Credit: NOAA.

A Recovery Success Story

Gray whales were hunted nearly to extinction during the whaling days. Thanks to legal protections, the U.S. population of gray whales recovered and was taken off the endangered species list in 1994 (though a second population of gray whales on the Russian side of the Pacific remains endangered).

This success presents scientists with a unique opportunity to study the ecology of large whales, including how environmental conditions put an upper limit on population growth. Because most other large whales are still threatened or endangered, scientists have had few opportunities to observe these dynamics in action.

"With gray whales, we're just beginning to understand what a recovered population of large whales looks like," Durban said.

This understanding will help scientists set recovery goals for other species. And once a species is recovered, it will help scientists distinguish between normal ups and downs in a population and signs of--should it happen--a more serious decline.

"We'll have to get used to seeing recovered populations have good years and bad years," Durban said. "That's what happens when you've recovered and you're hovering around a food ceiling."

As the sun descended toward the horizon, Durban brought the hexacopter in for the day's final landing. He still had a lot of work in front of him, minutely analyzing images on a computer screen. Though all the images from this study would be of gray whales, other species of large whale are also showing promising signs of recovery.

"Hopefully in the not-too-distant future," Durban said, "there will be many healthy populations of large whales to study."

Contact: Jim Milbury
NOAA National Marine Fisheries Service

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Climate change debate fueled by 'echo chambers,' new study finds

Photo by: Daniel Mennerich.

A new study from researchers at the University of Maryland (UMD) and the National Socio-Environmental Synthesis Center (SESYNC) demonstrates that the highly contentious debate on climate change is fueled in part by how information flows throughout policy networks.

The UMD and SESYNC researchers found that "echo chambers"--social network structures in which individuals with the same viewpoint share information with each other--play a significant role in climate policy communication. The researchers say that echo chambers may help explain why, despite a well-documented scientific consensus on the causes and drivers of global changes in climate, half of U.S. senators voted earlier this year against an amendment affirming that climate change is human-induced.

A peer-reviewed paper based on the study was published online May 25 in the journal Nature Climate Change.

"Our research shows how the echo chamber can block progress toward a political resolution on climate change. Individuals who get their information from the same sources with the same perspective may be under the impression that theirs is the dominant perspective, regardless of what the science says," said Dr. Dana R. Fisher, a professor of sociology at UMD and corresponding author who led the research.

In summer 2010, researchers surveyed the most active members of the U.S. climate policy network, including members of Congress and leaders of non-governmental organizations and business and trade unions. Respondents were asked questions about their attitudes toward climate science and climate policy, as well as questions to establish their policy network connections. For example, respondents were asked to identify their sources of expert scientific information about climate change and with whom they collaborate on a regular basis regarding the issue of climate change.

"This time period was particularly interesting for studying climate policy because legislation regulating carbon dioxide emissions had passed through the House of Representatives and was being considered in the Senate. If passed, this bill would have been the first case of federal climate legislation passing through the U.S. Congress," Fisher said.

The researchers then used an exponential random graph (ERG) model--a complex statistical model for analyzing data about social and other networks--to test for the presence and significance of echo chambers among members of the U.S. climate policy network. In the "echo," two people who have the same outlook or opinion on a relevant issue share information, reinforcing what each already believes. In the "chamber," individuals hear information originating from one initial source through multiple channels.

"The model we used gives us a framework for empirically testing the significance of echo chambers," said Dr. Lorien Jasny, a computational social scientist at SESYNC and lead author of the paper. "We find that the occurrences of echo chambers are indeed statistically significant, meaning our model provides a potential explanation for why climate change denial persists in spite of the consensus reached by the scientific community."

The researchers say that echo chambers explain why outlier positions--for example, that climate-warming trends over the past century are likely not due to human activities--gain traction in the political sphere. The answer lies in the disproportionate connections among ideologically similar political communicators.

"Information has become a partisan choice, and those choices bias toward sources that reinforce beliefs rather than challenge them, regardless of the source's legitimacy," Fisher said.

Jasny and Fisher point out that the debate on climate change is not indicative of inconclusive science. Rather, the debate is illustrative of how echo chambers influence information flows in policy networks.

"Our research underscores how important it is for people on both sides of the climate debate to be careful about where they get their information. If their sources are limited to those that repeat and amplify a single perspective, they can't be certain about the reliability or objectivity of their information," Jasny said.

Citation: Lorien Jasny, Joseph Waggle, Dana R. Fisher; An empirical examination of echo chambers in US climate policy networks; Nature Climate Change, 2015; DOI: 10.1038/nclimate2666.

Contact: Melissa Andreychek
National Socio-Environmental Synthesis Center

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Invisible helpers of the sea: Marine bacteria boost growth of tiny ocean algae

Diatoms are single-celled algae that take many intricate shapes. The Pseudo-nitzschia multiseries used in the study are simple rods that carry out photosynthesis throughout the world’s oceans. Credit: California Academy of Sciences

A glass of seawater is teeming with life, and recent research reveals more about what ocean water contains. Microscopic creatures in the world's oceans weigh more than all of the fish in the sea and produce about half of the Earth's oxygen.

Yet the ecology of marine microbes, which are crucial for everything from absorbing carbon dioxide from the air to regulating the productivity of major fisheries, are only beginning to be understood.

In a step to understanding this hidden world, University of Washington oceanographers have found that diatoms -- the intricately patterned single-celled algae that exist throughout the world's oceans -- grow faster in the presence of bacteria that release a growth hormone known to benefit land plants. The study, published online May 27 in Nature, uses genetic and molecular tools to discover what controls marine ecosystems.

"These very small organisms are interacting with their environment, but they're also interacting with other organisms," said co-author Ginger Armbrust, a UW professor of oceanography. "In my mind, in order to understand how future ecosystems will work, we need to understand how these organisms that are the basis of the marine food web interact with one another."

Armbrust's research group has long studied diatoms, which are microscopic algae that carry out one fifth of the planet's photosynthesis, more than all the terrestrial rainforests combined. Lab members began this project by looking at which bacteria were found in all samples of Pseudo-nitzschia multiseries, a common coastal diatom collected from five places throughout the northern Pacific and Atlantic Oceans. Next they cured the water samples of all bacteria living in the seawater, and found that the diatoms did not reproduce as well.

Co-author Shady Amin, a former UW postdoctoral researcher now on the faculty at New York University Abu Dhabi, added the bacteria common to all five samples back one at a time. One type, Sulfitobacter, sped up the growth dramatically when added back at a high enough concentration.

Black circles and triangles show the growth of diatoms collected from Golden Gardens in Seattle and Penn Cove on Whidbey Island, respectively. White circles and triangles are those same populations with the addition of sulfitobacter. Credit: V. Armbrust / Univ. of Washington

The authors showed that these bacteria exchange material with the diatoms while in turn producing auxin, a well-known hormone made by microbes living around the roots of land plants.

"The back-and-forth exchange of materials between these tiny creatures resembles an ongoing dialogue between two living organisms that culminates in the production of auxin," Amin said. "It was so fascinating that we wondered if we could see this behavior elsewhere."

Next, researchers went to sea and adopted some high-tech tools. Having shown what happens in the lab, they collected other ocean samples and found the same growth hormone. Then they used new genetic techniques to detect the activity of marine microbes -- famously difficult to raise in captivity -- that would never survive the transition to the lab. The same interaction was taking place, especially along coasts, but between different organisms that cannot be transferred to the lab.

"We're just at a place as a field where we recognize that there may be very specific interactions between marine microbes," Armbrust said. "Don't ask me how many comparable interactions are out there. I have no idea. I can only imagine that there's lots. And we've grabbed one of them."

She predicts that more such interactions will help to explain how ocean waters become or stay productive, or how the base of the marine food web might shift in a changing climate.

"A lot of the high-powered tools that look at the function of individual cells were developed in the medical world," Armbrust said. "Now that we can apply them to the ocean, we are starting to pull the curtains back on how this hidden world works."

Citation: S. A. Amin, L. R. Hmelo, H. M. van Tol, B. P. Durham, L. T. Carlson, K. R. Heal, R. L. Morales, C. T. Berthiaume, M. S. Parker, B. Djunaedi, A. E. Ingalls, M. R. Parsek, M. A. Moran, & E. V. Armbrust; Interaction and signalling between a cosmopolitan phytoplankton and associated bacteria. Nature, May 2015; DOI: 10.1038/nature14488.

The research was funded by the National Science Foundation and the Gordon and Betty Moore Foundation.

Contact: Hannah Hickey
University of Washington

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Building expertise to protect the Serengeti

EU Horizon 2020 grant brings together researchers from Africa and Europe.

The wildebeest migration in Serengeti National Park is one of its defining features. While some environmentalists have worried about the effect of a road in the park on the animals' movements, researchers in a new EU funded project are looking at how population growth and climate change affect the ability of the park to survive into the future. Photo: Per Harald Olsen/NTNU

A huge wildebeest herd migrates across the open, parched plains. Dust swirls up from the many hooves pounding the ground, and forms a haze over the landscape. The setting sun gives the scene a golden tinge.

The herd is heading towards one of the life-giving water holes, where wildebeest congregate along with zebra, gazelles, antelopes, elephants and other species of the abundant animal population that live in the Serengeti and make the area unique.

An image of Africa

This iconic image of the national park is far from guaranteed in perpetuity. Serengeti means "endless plains" in the Maasai language, but the national park is pressured from many quarters and is changing quickly. A large EU-funded research project is taking stock of what is happening in the Serengeti.

"The Serengeti is in many ways an iconic image of Africa, and we'll use the Serengeti as our case study in this research project," says Eivin Røskaft, a biology professor at the Norwegian University of Science and Technology (NTNU), who is heading the entire 10 million euro EU project.

Serengeti National Park in Tanzania extends into Kenya towards the Mau Forest, the largest virgin montane forests of Africa. The Mara River, which originates in the Mau Forest, is the lifeblood of the entire ecosystem of the national park. Together the Mara River, the Mau Forest and the Serengeti constitute one of the world's most complex ecosystems, and they support a great diversity of fauna and birdlife, as well as special and rare plants.

Nature provides vital resources

The region also offers crucial resources such as vitally important water, food for animals and humans, wood for fuel and construction, land that can be cultivated -- and nature experiences.

"Everything we harvest from nature are services that the ecosystem services provides us. These resources are deteriorating little by little, and what we see in the Serengeti is that the pressures on the ecosystem can become so large that that they are no longer sustainable. In the worst case, the Serengeti could disappear completely in a few decades," says Røskaft.

What makes the Serengeti especially vulnerable is that residents of the area live close to the park and are completely dependent on nature. Because of this, the consequences of changes in natural resources are immediately apparent. The area lends itself well to research because scientists can extract clear data.

Moreover, much research has already been conducted in the Serengeti, so a large amount of material already exists on which to build, which enables scientists to see longitudinal changes.

Huge population growth

Researchers are studying three different drivers of the pressure on the Serengeti-Mara ecosystem. One of the drivers is climate change. In recent years, the climate has become warmer, the dry season longer and the rains more powerful, resulting in soil erosion and washouts. The wet season has also shifted. All these factors create challenges for vegetation, animals and humans in the area.

Population growth is another driver. In 1961 Tanzania had 8,000,000 inhabitants. Today the number is 50,000,000, and in 20 years it is estimated to double. The population growth increases the need for food, and both legal hunting and poaching of wildlife have escalated in the Serengeti-Mara. Livestock numbers have also increased, intensifying the pressure on pasturelands.

Cooking primarily takes place on open fires, and the population growth means a growing demand for more firewood and building materials. The unique Mara Forest is now in the process of being cut down. Due to the expanding population, people are pushing farther and farther into the national park to extract natural resources.

Researchers are investigating the development of infrastructure. People in the area have gained greater access to electricity, and most Tanzanians are more prosperous than before. The road network is being developed, including a road planned to run through the national park that will cross the wildebeest migration route. This has generated great debate both nationally and internationally.

The Serengeti is home to giraffes and many other ungulates. Photo: Per Harald Olsen, Norwegian University of Science and Technology.

A better road can lead to more AIDS

Besides the three main drivers of change in the Serengeti, says Røskaft, the researchers will also examine how these factors are affecting the wildebeest population and the life cycles of wildebeest, zebra, impala and African wild dogs.

The scientists are also mapping changes in disease prevalence. Malaria and sleeping sickness spread via insects (malaria mosquitoes and tsetse flies), and climate change can alter the pattern of disease transmission. Road construction enables people to move more and over longer distances, potentially leading to an increased spread of AIDS.

Researchers are also mapping demographic changes in population growth, fertility and mortality.

Norway is in the driver's seat

Nearly 100 scientists are involved in the research project entitled "Linking biodiversity, ecosystem functions and services in the Serengeti-Mara region, East Africa." The researchers come from 13 different research institutions in Kenya, Tanzania, Denmark, Norway, Germany, Scotland and the Netherlands. Norway, via NTNU and Eivin Røskaft, are in the driver's seat for the project.

Thirteen people from NTNU are involved so far: five professors, three researchers, two technical personnel and three doctoral students. In addition, more master's students and doctoral candidates will join the research team, and several of NTNU's students and PhD candidates on the project come from Tanzania.

In answer to the question of what he considers the most important aspect of this project, Røskaft responds that "the most important thing is to strengthen expertise in Tanzania. My top goal and motivation are to build up good and safe professional expertise with Tanzanians. It's rewarding to see people gain confidence and faith in the job that they do."

Major international players like WWF and IUCN will and can influence what happens in the Serengeti. Many international stakeholders have waged massive protests against road construction, for example.

"Especially for countries like Kenya and Tanzania, which have such abundant natural resources, it is important for locals to have the necessary expertise to make their own assessments based on sound professional judgment," says Røskaft.

Dream of Africa

Røskaft's journey into Serengeti research began in childhood. He says, "I've always had a strong fascination for Africa. As a kid I collected postcards with images of wild animals from Africa, and I read books on the Serengeti. Just like some athletes, I can say: This is a boyhood dream that has come true." When news of the award came, he found himself in the middle of Serengeti National Park. On top of that, the news arrived on his birthday.

"It was an indescribable honour. To be awarded EU funding is recognition of the research we're doing, so we have every reason to be proud of this," says the Africa researcher. Currently, this is NTNU's largest EU project.

Contact: Eivin Røskaft
Norwegian University of Science and Technology

 

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Enhancing knowledge crucial to improving energy-saving behaviors

Increasing public knowledge and understanding about energy issues is vital if improved energy-saving behaviours are to be encouraged among individuals and organisations, a study suggests.

A survey conducted at Plymouth University indicated widespread misconceptions about energy which researchers said may be reducing the effectiveness of energy-saving behaviours.

It also showed varying levels of motivation and engagement with energy issues, with respondents saying they were uncertain about their capacity to influence business and government on matters of environmental importance.

The study - published in Local Environment: The International Journal of Justice and Sustainability - was carried out in an attempt to develop a more integrated understanding of energy literacy and to draw out connections between knowledge, attitudes and behaviours.

Professor Debby Cotton, lead author on the report, said: "Energy use affects every aspect of contemporary life, and energy saving is a crucial part of our response to climate change and fossil fuel depletion. But despite a range of energy-related behaviour change initiatives in education and public life, 'energy literacy' among citizens remains patchy. Studies have in fact shown that environmental concerns in some countries are at a 20-year low, and without strong motivation for changing behaviours, there is limited potential for energy consumption to be further reduced."

The research involved academics from three areas of the University - which as an institution has won four Green Gown Awards and topped the People and Planet Green League in 2015 - including the Pedagogic Research Institute and Observatory (PedRIO), the School of Geography, Earth and Environmental Sciences and the Centre for Sustainable Futures.

They analysed more than 1,100 responses to a questionnaire, which asked participants about their knowledge of energy issues and any current energy saving measures they employ.

Results showed that more than 90% of respondents considered themselves at least somewhat informed on global energy issues, while 21% of females and 16% of males felt limiting climate change was the most important issue facing the UK today.

Three-quarters recognised their behaviours could make a difference to the energy situation, but less than half felt they had the power to influence the actions of government (45%) and companies (48%) to solve energy problems.

The majority of respondents said they tried to employ energy saving behaviours, such as turning off lights (97%), walking or cycling for short journeys (88%) and turning down heat in their homes (80%), and 54% claimed they always or frequently tried to convince friends to alter their energy behaviour. However, there was widespread misunderstanding about which actions saved most energy - thus behavioural choices were not always the most effective.

In their conclusion, the authors say: "This research particularly emphasises the importance of not overlooking knowledge as a means of improving the prospects for informed decision-making in both existing and new contexts. It suggests that greater efforts are needed to link formal learning with daily life to enhance awareness of how individuals use energy in everyday practices and illustrate how changing behaviours affect energy use. Collective action is frequently identified as playing a key role in adaptation to environmental change, yet our findings offer depressing reading on this front and suggest an increasing focus on individualism."

Citation: Debby Cotton, Wendy Miller, Jennie Winter, Ian Bailey, Stephen Sterling. Knowledge, agency and collective action as barriers to energy-saving behaviour. Local Environment, 2015; 1 DOI: 10.1080/13549839.2015.1038986.

Contact: Alan Williams
University of Plymouth

 

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Birds 'weigh' peanuts and choose heavier ones

Mexican Jays (Aphelocoma wollweberi) handling peanut pods appear to evaluate the pod content by 'weighing' the pods and by 'listening to' them. Credit: M. Fuszara.

Many animals feed on seeds, acorns or nuts. The common feature of these are that they have shells and there is no direct way to know what's inside. How do the animals know how much and what quality of food is hidden inside? A simple solution would be to break the shells, which often takes time and effort -- it would be a big disappointment to know that it's rotten or bad after the hard effort of opening the nuts!

Can animals evaluate the food hidden inside the nuts? This is especially important for some animals who cache the food items for later use without opening and checking each item. We can detect which one is heavier by moving the items up and down several times and focusing on the "feeling of heaviness" we perceive. Humans can also detect the quality of a water melon by knocking on it.

A new study published in Journal of Ornithology suggests that some birds can also use similar tricks in choosing the peanuts from the feeder. Ther study was carried out in Arizona by an international research team from Poland and Korea and revealed that the Mexican Jays (Aphelocoma wollweberi) may be able to "weigh" peanuts and maybe even "listen to" peanuts while handling them in their beaks. Drs. Sang-im Lee, Piotr Jablonski, Maciej and Elzbieta Fuszara, the leading researchers in this study, together with their students and helpers, spent many hours delicately opening shells of hundreds of peanuts, changing the contents and then presenting them to the jays in order to see if the birds can figure out the differences in the content of identically looking peanut pods (peanuts in shell).

"When we presented the jays with ten empty and ten full identically looking pods (pods without or with three nuts inside), we noticed that after picking them up the birds rejected the empty ones and accepted the full peanuts, without opening them." says Dr. Sang-im Lee of Seoul National University -- the corresponding author of the paper. A series of similar experiments with identically looking normal nuts and nuts that were 1g heavier (pods with some clay added) confirmed that jays always were able to distinguish and preferred the heavier nuts. How did they know which were empty without opening them? The researchers used slow motion videos to see what happens when the bird is deciding whether to drop or take away the peanut pod. "We found out that birds shake the nuts in their beaks. We think that these movements may provide them with the information generally similar to our feeling of "heaviness" when we handle an object in our hands", says Dr. Jablonski.

 

In another experiment the researchers prepared one type of peanut pods by opening the shell, removing two out of the three nuts and closing the shell again. The second type of pod was prepared by opening a small pod, which normally contains only one nut, and closing it. Thus, the jays were to choose between nuts of similar content and mass but of different size. "The jays figured out that the larger pods did not weigh as much as they should and the birds preferred the smaller pods, which weighed as expected for their size", comments Dr. Fuszara. They behaved as if they knew that "something is wrong" with the larger nuts.

So how do they know it? When they shake the nuts in their beaks, the birds produce sounds by opening and closing their beaks around the peanut shell for brief moments. The researchers think that the jays also take this sound into account. "Our next goal is to disentangle the role of sound relative to the perception of "heaviness", and to determine if jays use the same sensory cues for acorns -- their natural food", conclude Dr. Lee and Dr Jablonski.

Citation: Jablonski PG, Lee SI, Fuszara E, Fuszara M, Jeong C., Lee WY. 2005. Proximate mechanisms of detecting nut properties in a wild population of Mexican Jays (Aphelocoma ultramarina). Journal of Ornithology, DOI: 10.1007/s10336-015-1193-6.

Contact: Sangim Lee
Laboratory of Behavioral Ecology and Evolution at Seoul National University