Warmer water, less nutrition

The nutritional value of giant kelp decreases as sea temperatures increase

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - SANTA BARBARA

As a foundational species, giant kelp (Macrocystis pyrifera) is vital to the ecosystem of the temperate, shallow, nearshore waters where it grows. When the kelp flourishes, so do the communities that rely on the fast-growing species for food and shelter.

Giant kelp has proven resilient (so far) to some stressors brought on by climate change, including severe storms and ocean heatwaves — an encouraging development for those interested in the alga’s ability to maintain the legions of fish, invertebrates, mammals and birds that depend on it for their survival. But in a recent study published in the journal Oikos, UC Santa Barbara researchers reveal that giant kelp’s ability to take a temperature hit may come at the cost of its nutritional value.

“The nutritional quality, or the amount of nutrients in the kelp tissue seems to be changing,” said the study’s lead author Heili Lowman, a biogeochemist with the University of Nevada, Reno, who conducted this research as a Ph.D. student in the Department of Ecology, Evolution and Marine Biology at UC Santa Barbara. “We found that those changes were associated or correlated with changing seawater temperatures. From a big-picture standpoint, that’s pretty important because there are a lot of things that rely on kelp as the primary food source.”

“I guess you could call it one of the more hidden effects of ocean warming,” said study co-author and graduate student researcher Kyle Emery. “We haven’t necessarily lost kelp in places that have had these big temperature increases, but the kelp there has declined in terms of its nutritional content. So although it’s still there, it’s not able to provide the same function as when temperatures are lower.”

These findings of ocean warming’s hidden effects on kelp come from long-term data gathered at UCSB’s Santa Barbara Coastal Long-Term Ecological Research (SBC-LTER) site, which consists of several kelp forests located in the Santa Barbara Channel. Thanks to data collected over almost two decades, researchers have been able to track patterns of nutrient content, which fluctuate seasonally, and identify significant trends.

“The temperature of the seawater and nutrient availability are really closely coupled in the Santa Barbara Channel, and we’ve known that for some time,” Lowman said. Generally, the cooler temperatures bring nutrient-rich waters up from the deep, but during the warmer seasons, nutrients in the shallows and upper ocean — particularly nitrogen — become more scarce.

“Physiologically, kelp plants can’t store nitrogen for longer than a couple weeks, so whatever’s happening around them in the water they’re going to respond to very quickly because they need a constant supply of nitrogen to grow, and to continue to reproduce,” she said.

Knowing this pattern, the researchers then sought out how nutrient content might play out over a longer period of time, as ocean temperatures rose. They did so by looking at data from the primary productivity sampling that is conducted in the waters at the SBC LTER on a monthly basis.

“As part of that sampling, kelp blades are collected from these sites, brought back to the lab and then processed for carbon and nitrogen content,” Emery explained.

Over the 19-year period covered by the SBC LTER, according to the paper, nitrogen content of the giant kelp tissue declined by 18%, with a proportional increase in carbon content, according to the paper.

This apparent decline in nutritional content does not bode well for the consumers of kelp in and around the Santa Barbara Channel, which include sea urchins and abalone in the water, and intertidal beach hoppers and other invertebrates that consume the kelp wrack that washes up on the shore.

“As a result, urchins, for example, might go in search of a lot more kelp and that could cause a shift in certain places, potentially from a kelp forest to an urchin barren, if they’re just mowing down the reef looking for more food,” Lowman said. Animals that feed on kelp might also expend more energy trying to eat enough to fulfill their nutritional requirements.

While urchins have the ability to go searching for more food, Emery added, the consumers on the shore are stuck with what they get.

“If you have greater demand, but there’s not more kelp coming in, that poses a pretty challenging situation for them, whether it’s being underfed or through population declines,” he said.

In both cases, the effects could ripple out to the rest of the food web, the researchers said: Lower-nutrition kelp could mean smaller, fewer, perhaps less healthy beach hoppers, for instance, which would lead to less food for the shorebirds that eat them. In the water, less nutrition for urchins and abalone could mean less food for their consumers, including fish, lobster, sea otters and humans.

“Our results raise a lot of really interesting open-ended questions and suggest a lot of far-reaching effects,” Emery said.

Having explored the potential relationships of seawater temperature to nutritional content, the researchers are considering broadening the spatial scale of the study.

“The next step would be thinking about what all is playing into determining the nutritional content and then how might we then be able to predict it into the future,” Lowman said.

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JOURNAL

Oikos

ARTICLE TITLE

Nutritional quality of giant kelp declines due to warming ocean temperatures

ARTICLE PUBLICATION DATE

26-Oct-2021

WHY ISN'T THIS FRONT PAGE NEWS

Affordable policy which could stop fossil fuels causing global warming - report

Stop fossil fuels causing global warming within a generation... The Carbon Takeback Obligation could do just that

Peer-Reviewed Publication

UNIVERSITY OF OXFORD

Imagine a single policy, imposed on one industry, which would, if enforced consistently, stop fossil fuels causing global warming within a generation. The Carbon Takeback Obligation could do just that. It requires fossil fuel extractors and importers to dispose safely and permanently of a rising fraction of the CO2 they generate, with that fraction rising to 100% by the year of net-zero. Critically, this would include carbon dioxide generated by the products they sell.

A ground-breaking study by the Universities of Oxford and Edinburgh, published Tuesday [embargoed to 11am US ET] in the international energy journal Joule, explores the economic implications of imposing a carbon takeback obligation on the global fossil fuel industry, and shows it provides an affordable and low-risk route to net zero emissions, particularly if complemented by conventional measures to reduce near-term fossil fuel demand.

Oxford researcher Stuart Jenkins, lead author of the study, explains, ‘Despite the perceived high cost of carbon dioxide capture and storage, we show that the cost to the world economy of a Carbon Takeback Obligation, even if entirely passed on to fossil fuel consumers, is no higher than the cost of mitigation in conventional scenarios meeting similar goals driven by a global carbon price.’

Professor Stuart Haszeldine of the University of Edinburgh, a report co-author, says, ‘Investment in carbon dioxide capture and geological storage has, to date, been dependent on state subsidies, and consistently far below what is required to meet Paris climate goals. Carbon Takeback provides the fossil fuel industry itself with the strongest possible incentive to make amends: survival.’

Oxford’s Professor Myles Allen, another co-author adds, ‘Carbon Takeback has consistently been dismissed by the climate policy establishment as much more expensive and risky than the alternative of driving down consumption by changing consumer behaviour or through a global carbon price. But these options are hardly risk-free. Getting to net zero means carbon prices rising to $1000 per tonne of CO2 by 2050: 100 times the hike that brought out the gilets jaunes.’

Margriet Kuijper, an independent expert in carbon capture and storage who reviewed the work, comments, ‘A Carbon Takeback policy as proposed in this paper will provide a safety net to make sure we achieve net zero emissions even if we don’t manage to reduce the use of fossil fuels quickly enough. It extends the responsibility of producers to take care of the waste generated by the use of their products. The polluter pays to clean up. And the costs are included in the product price. As it should be.’

Notes to Editors:

The paper: Upstream decarbonisation through a Carbon Takeback Obligation: an affordable backstop climate policy is the Climate & Energy highlight of this week’s issue of the journal Joule published Tuesday, October 26, embargoed to 11am US ET. It will be available on https://www.cell.com/joule/fulltext/S2542-4351(21)00489-X when the embargo lifts

True Planet: Oxford research for a changing world

The world around us is changing, and Oxford researchers are at the forefront of trying to understand better the reasons for global temperature and sea level increases, extreme weather events, plastic waste proliferation and threats to biodiversity.

Our researchers are working with partners in industry, government, the third sector and at other universities to address these challenges and to propose innovative approaches and solutions. Find out more about our True Planet campaign.

The University of Oxford

Oxford University has been placed number one in the Times Higher Education World University Rankings for the fifth year running, and at the heart of this success is our ground-breaking research and innovation. Oxford is world-famous for research excellence and home to some of the most talented people from across the globe. Our work helps the lives of millions, solving real-world problems through a huge network of partnerships and collaborations. The breadth and interdisciplinary nature of our research sparks imaginative and inventive insights and solutions.

 

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JOURNAL

Joule

DOI

doi: S2542-4351(21)00489-X 

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Upstream decarbonisation through a Carbon Takeback Obligation: an affordable backstop climate policy

ARTICLE PUBLICATION DATE

26-Oct-2021

UBC researchers are helping communities prepare for the effects of climate change

Business Announcement

UNIVERSITY OF BRITISH COLUMBIA

 

IMAGE: AN EXAMPLE SCREENSHOT OF THE CANADIAN HAZARDS EMERGENCY RESPONSE AND PREPAREDNESS MOBILE APP (CHERP) APP. view more 

CREDIT: CHERP RESEARCH TEAM

The 26th United Nations Climate Change Conference of the Parties (COP26) takes place next week and one of its four goals is to help countries adapt to climate change in order to protect communities and natural habitats.

From creating disaster preparedness apps to training local climate champions, UBC researchers are already working with communities to help them prepare for the effects of climate change.

App-daptation for disasters and hazards

Planning for a disaster can be scary, but UBC researchers are making it easier with a new app tailored to individual households.

Dr. Ryan Reynolds, a postdoctoral researcher in the faculty of applied science's school of community and regional planning, found residents in Port Alberni were confused as to which households were at risk and where to find information following a tsunami warning and evacuation in 2018.

Hoping to address this gap, his team has created the Canadian Hazards Emergency Response and Preparedness Mobile App (CHERP) app, which will be piloted in seven communities on Vancouver Island starting next month. “I know from speaking with people post-disaster that anything we can do to reduce that confusion goes a long way to building trust in emergency responses.”

The app helps residents create preparedness, communication, evacuation and on-the-day emergency response plans for local hazards and potential disasters such as sea level rise or coastal flooding. Not sure if your household is in the inundation zone for a tsunami warning? The app will tell you based on your location.

A thorough list of inputs helps individualize plans for each household, including whether someone menstruates, has anxiety, accessibility issues, is part of the LGBTQ+ community, signs, is a refugee or in Canada on a temporary visa. And pets aren’t forgotten: users can input the number of animals in their household.

Preparing for emergencies is like insurance, says Dr. Reynolds. “You do a little bit of work now and hopefully reap the benefits down the road. We know things like sea level rise, coastal flooding, tsunamis, are going to happen and we can put steps in place to prepare.”

CAPTION

An example screenshot of the Canadian Hazards Emergency Response and Preparedness Mobile App (CHERP) app.

CREDIT

CHERP research team

Wine, cheese and climate change

Tackling climate change over wine and cheese with your neighbours sounds too good to be true. But Dr. Stephen Sheppard, a professor emeritus in the department of forest resources management in the faculty of forestry, says local climate change action should be fun. “If you can get people to do things together, you get safer, more resilient neighbourhoods but also stronger communities. You could go to the pub, have some fun with it – it’s got to be fun, or no one will do it.” 

Over the next 12 months, his team will train local residents for Cool 'Hood Champs, a free program hosted by four Vancouver community centres. In a series of three workshops, participants learn to identify local climate targets, impacts and solutions, and craft their own climate action plans with practical actions, ranging from installing a shade for a vegetable garden to watering neighbourhood trees during a drought.

This year’s program is an extension of a pilot from last year, where 29 out of 37 participants completed all the workshops, and 70 per cent chose to take home trees to plant in their yards. Local action is vital, says Dr. Sheppard, because individual behavioural decisions affect whether governments achieve emissions targets, and practical solutions can help people feel better. “What can you do about climate change? You can ignore it, worry about it, or do something about it, using processes you can control.’

Dr. Sheppard and his team are also piloting a three-year program with Oak Bay council, where citizen workshops will be hosted through community hubs including schools, churches, and volunteer programs, with funding and staff support. “The pilot will show with backing and funding, citizens themselves can run workshops, take local action and involve others, sustainably.” 

CAPTION

An example screenshot of the Canadian Hazards Emergency Response and Preparedness Mobile App (CHERP) app.

CREDIT

CHERP research team

Adaptation, not maladaptation

However, climate adaptation interventions are not automatically positive, says Dr. Sameer Shah (he/him), a sessional lecturer at the UBC Institute for Resources, Environment and Sustainability (IRES) in the faculty of science. When applied without consideration of the social context, they can deepen inequities.

In a study published in June, Dr. Shah and colleagues looked into the Government of Maharashtra’s campaign in India to make 25,000 villages drought-free by 2019, a campaign that cost nearly US$1.3 billion.

The team interviewed households in three villages, as well as government officials and key informants, and found that government interests had led to a narrow focus on certain types of water conservation interventions. These benefited a particular group of people, generally those who were already well-off, and often excluded those who didn’t have enough land or money to invest in water-related adaptations, or were located further away from waterbodies, including members of historically disadvantaged groups.

According to a 2020 report by the Comptroller and Auditor General of India, the campaign had little impact in achieving water neutrality and increasing groundwater level.  Here, technical solutions are not enough, says Dr. Shah, and interventions need to incorporate the social context in which they occur. “As researchers, we can’t just say ‘this is the science’ for an intervention, and then hang up our hats. We need to be focused on issues of governance and distribution.”

Getting the global community involved

When it comes to climate action on mitigation and adaptation, we need everyone involved, says Dr. Jiaying Zhao, Canada Research Chair in Behavioral Sustainability and associate professor at IRES and the department of psychology in the faculty of arts.

She and her colleagues have posited a set of interventions to target different subsets of the entire population to make sure no one is left behind.

Two of these five groups, the “late majority” and the “laggards”, make up 50 per cent of the population and are often overlooked by behaviour change interventions, the authors say.

The “late majority" are characterized as adopting climate actions to fit in with others. Interventions include using social norms, peer pressure, and peer influence to encourage climate action. The “laggards”, or those most reluctant to act, need peer role models to deliver messages and to endorse climate action, says Dr. Zhao. “You need to use the right messenger to deliver the right message.”

Policy makers and researchers should acknowledge these different groups of people and their distinct motivations for climate action, and tailor interventions to each group, she says. “We should get everyone onboard, not just the keeners, as soon as possible.”

Citizen scientists’ contributions a boon to snowpack modeling, OSU research shows

Peer-Reviewed Publication

OREGON STATE UNIVERSITY

 

IMAGE: OSU CIVIL ENGINEERING PROFESSOR DAVID HILL CHECKS SNOWPACK DEPTH. view more 

CREDIT: KENDRA SHARP, OSU

CORVALLIS, Ore. – Data gathered by backcountry skiers, avalanche forecasters and other snow recreationists and professionals has the potential to greatly improve snowpack modeling, research by the Oregon State University College of Engineering indicates.

Findings, published in the journal Hydrology and Earth System Sciences, stem from a NASA-funded project known as Community Snow Observations, or CSO, part of NASA’s Citizen Science for Earth Systems program.

The paper is the first documentation of CSO’s power to make snowpack modeling better through “organic, opportunistic” data – a notable outcome, said researcher David Hill.

“We have shown citizen scientist contributions are very valuable and that we can do great things in the absence of observational network infrastructure,” said Hill, professor of civil engineering at OSU. “In this study, we used a new data set collected by CSO participants in coastal Alaska to improve snow depth and snow-water equivalent outputs from a snow process model.”

In western North America, snow’s role in ecosystem function and water resource management is critical, the scientists say, and around the world more than a billion people live in watersheds where snow is a major component of the hydrologic system.

“Snowpack dynamics in the mountains have a big role in connecting atmospheric processes and the hydrologic cycle with downstream water users,” said Chris Cosgrove, an OSU graduate student during the research. “At our Alaska field site, hydroelectric power generation is the principal concern, but in the lower 48, many agricultural producers and municipal water systems rely on seasonal snow.”

In 2017, NASA enlisted Hill and doctoral student Ryan Crumley, as well as researchers at the University of Washington, the University of Alaska Fairbanks and the Alaska Division of Geological & Geophysical Surveys, to recruit citizen scientists and incorporate their data into computer models that generate important snowpack information for scientists, engineers and land and watershed managers.

Community Snow Observations kicked off in February 2017 and since then thousands of data entries have been made. Led by Hill, Gabe Wolken of Alaska Fairbanks and Anthony Arendt of the University of Washington, the project first focused primarily on Alaskan snowpacks. Researchers then recruited citizen scientists in the Pacific Northwest and in the Rocky Mountain region.

The work is ongoing and getting involved in Community Snow Observations is easy. A smartphone, the free Mountain Hub application and an avalanche probe with graduated markings in centimeters are the only tools needed.

As citizen scientists make their way through the mountains, they use their avalanche probes to take snow depth readings that they then upload into Mountain Hub, an app for the outdoor community.

That’s all there is to it.

“We’ve now taken our modeling work operational,” Hill said. “We serve up real-time grids on snow information at many sites across the United States, including the central Cascades in Oregon, at mountainsnow.org. The general public can go there and view real-time information on snow, snow changes and other things like satellite measurements of snow.”

In the recently published research, Hill and Crumley, who’s now at the Los Alamos National Laboratory, teamed with Wolken, Arendt, Cosgrove and OSU graduate student Christina Aragon to look at how snowpack models for the Thompson Pass region of Alaska’s Chugach Mountains improved when citizen science measurements were incorporated.

“Improvements were seen in 62% to 78% of the simulations depending on the model year,” Aragon said. “Our results suggest that even modest measurement efforts by citizen scientists have the potential to improve efforts to model snowpack processes in high mountain environments.”

Information about snow distribution reaches scientists from many sources, including telemetry stations and remote sensing via light detection and ranging, or LIDAR, but the simplicity of the citizen science data gathering approach allows for many gaps to be filled, the scientists say.

“Snow depth measurements can be made accurately and quickly by anyone with a measuring device,” Crumley said. “The potential of mobilizing a new type of data set collected by people like snowshoers and snow machiners is significant because those folks often go to remote mountain environments where so far there haven’t been many observations recorded. All of those people can gather data at scales much greater than the capacity of a small group of scientists.”

Also collaborating on this research was Katreen Jones of the Alaska Division of Geological and Geophysical Surveys.

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JOURNAL

Hydrology and Earth System Sciences

DOI

10.5194/hess-25-4651-2021 

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Assimilation of citizen science data in snowpack modeling using a new snow data set: Community Snow Observations

ARTICLE PUBLICATION DATE

31-Aug-2021

COI STATEMENT

The authors declare that they have no conflict of interest.

Project aims to improve accuracy of climate change models

Grant and Award Announcement

CORNELL UNIVERSITY

ITHACA, N.Y. - There’s broad scientific consensus that, because of climate change, the western U.S. will have less water and the northeastern U.S. will have more. But how much less and how much more is deeply uncertain, presenting a critical challenge for the scientists, policymakers and public servants tasked with ensuring the nation’s water supply.

Flavio Lehner, assistant professor of earth and atmospheric sciences at Cornell University, is working to reduce that uncertainty, by improving the climate models on which future water projections are based. Lehner won a three-year, $500,000 grant from the National Oceanic and Atmospheric Administration (NOAA) to do that work, beginning this fall.

Dan Barrie, a program manager in NOAA’s Climate Program Office, said Lehner’s work will improve NOAA’s climate models and enable the agency to make better short-term predictions of floods and droughts and better long-term projections of how surface water systems will evolve in the 21st century.

“The United States is experiencing profound changes in its regional water resources,” Barrie said. “It is more urgent than ever to have the best modeling tools to provide a vision of these future changes so that we can take cost-effective measures now to mitigate and adapt to them.”

Lehner’s research, which will improve climate modeling globally, was based on similar research he began in the Colorado River. Current estimates predict that for every degree Celsius of global warming, the Colorado River will lose between 3 to 15% of its streamflow.

Lehner compared the differences in climate models to the disparity in human reactions to COVID-19 – assessing whether an individual has COVID-19 is relatively simple, but predicting how sick the virus will make each person is much more difficult. A similar principle is at play in climate modeling, he said.

“For example, for the Colorado River, all of the numbers point in the same direction – in a warmer climate, there will be less water. But the big uncertainty is how much less,” Lehner said.

To test the sensitivity of climate models, Lehner’s group is studying 70 years of data on precipitation, temperature and streamflow, to assess how well current models would have predicted what actually happened.

“The most important question to us is: How sensitive are these models to changing environmental factors, such as changes in temperature and atmospheric greenhouse gases? And is their sensitivity consistent with what we see in reality?” he said.

The models Lehner and colleagues are using are more complicated and ultimately more useful because they take into account multiple interacting systems. Rather than just measuring rainwater or groundwater, Lehner is examining how atmospheric, terrestrial and hydrologic systems interplay, in the presence of increasing temperatures and atmospheric greenhouse gases. For example, there is now 40% more carbon dioxide in the air today than there was 100 years ago, and the earth is 1 degree Celsius warmer.  Even if precipitation remained neutral, those changes would cause plants to alter their behavior – consuming more groundwater to prevent parching, and thus leaving less to become stream runoff available to humans. But with added complexity comes added uncertainty.

“We already have a sizable uncertainty because we don’t know how much precipitation is going to change, but if you go one step further and say, how does runoff or streamflow change? The uncertainty becomes even larger,” Lehner said.

Modern climate modeling expanded dramatically in the 1980s and has provided useful and accurate information to help scientists and policymakers plan and adapt, Barrie said. Since 1980, the U.S. has experienced an average of 7.1 major weather or climate disasters per year, each causing losses of more than $1 billion. But in the past five years, the annual average of major disasters has jumped to 16.2, according to NOAA.

“Improving climate models is one step to ensuring that equitable adaptation efforts can be implemented to minimize net negative impacts on people and the economy. The cost of investments like Dr. Lehner's research project pales in comparison to the magnitude of the potential benefits,” Barrie said.

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Waters off French coast in winter may be a deadly trap for small, foraging turtles

The movement of turtles rescued from the French coast suggests they are visiting to forage for food, but small individuals may get trapped there in colder months

Peer-Reviewed Publication

FRONTIERS

The documented habitat boundaries of the loggerhead, Kemp’s ridley and green turtles are questioned by a new study suggesting that stranded turtles rescued from European French Atlantic and Channel waters could be visiting the area to forage for food. Published in Frontiers in Marine Science, satellite tracking data reveals that while some turtles may be able to return home, after their rehabilitation and release to Florida in the US, or Cape Verde off the African coast, younger individuals are at risk of being trapped in the region.

“Stranded turtles that were tracked swimming westwards presumably towards their birth homes, after their rescue and release from the Atlantic coast of France, were older and more developed than those that remained in the Bay of Biscay region,” said Dr Philippine Chambault, first author of this study, based at the Aquarium La Rochelle, France. “Turtles that remained in the area were much smaller, possibly trapped in the winter, as they are not able to regulate their body temperature and get lethargic with decreasing sea temperatures.”

“These findings have important turtle conservation implications,” added Florence Dell'Amico, co-author of the study, who oversees the Center of Studies, and cares for the sea turtles at the Aquarium La Rochelle. “Maps of their ecological range need to be updated, and these study findings can help to plan effective rehabilitation and release strategies for turtles rescued from this area.”

Rescue and rehabilitation

The Aquarium La Rochelle has rescued and rehabilitated more than 200 turtles from the east Atlantic coast of France in the past 40 years. To ensure the turtles they were caring for had the best chance of survival after their reintroduction back into the wild, the center wanted to understand where they travelled to after their release.

“Were the turtles returning to their natal beaches or staying within the Bay of Biscay region? To find out, we glued miniaturized satellite transmitters to the shells of some rescued turtles, which would track their movements over several months,” said Dell'Amico.

“In addition, we used the Copernicus Marine Service to obtain information on the currents, water temperatures and prey abundance along turtles’ trajectories. This enabled us to link turtle movement patterns to these oceanic factors, as well as the size and mass of the turtles,” explain Dr Philippe Gaspar, co-author of the study based at Mercator Ocean, France.

Too cold for small turtles?

“The Bay of Biscay waters are especially cold during wintertime, less than 10°C, and so this area is assumed to be outside the geographical range for turtles. Our observations suggest that while the turtles could be visiting this area to forage for food, it may be an ecological trap for very small turtles that may suffer from hypothermia in the cold months,” said Gaspar. “A turtle’s body temperature is largely controlled by the temperature of the environment, and temperatures below 10oC are often lethal.”

The team hope to satellite track more turtles in the region to confirm the surprising movement patterns they observed in this study.

“Future work should also focus on genetic analysis and computerized simulations of turtle movement across oceans to compare their routes back to their birth home to their natal origin. Simulations of juvenile turtle dispersal from the beaches that they were born should also be conducted to assess the proportion of individuals that reach western Europe,” concluded Chambault.

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JOURNAL

Frontiers in Marine Science

DOI

10.3389/fmars.2021.736604 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

Ecological trap or favorable habitat? First evidence that immature sea turtles may survive at their range-limits in the North-East Atlantic

ARTICLE PUBLICATION DATE

26-Oct-2021

COI STATEMENT

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

An international team of scientists, lead by researchers at UC Santa Barbara, will investigate how elephants shape their environment even after death

The nutrients from the giant mammals could be crucial to the character of the African savanna

Grant and Award Announcement

UNIVERSITY OF CALIFORNIA - SANTA BARBARA

 

IMAGE: AN ELEPHANT CARCASS IN KRUGER NATIONAL PARK. THE BARE AREA OF SOIL WAS CREATED BY CARCASS DECOMPOSITION AND DISTURBANCE FROM SCAVENGERS. view more 

CREDIT: DERON BURKEPILE

Big animals have a big impact on the environment. Whales, elephants, bison: They’re the movers and shakers of their ecosystems. But what happens when they die?

An international team of researchers, led by professors at UC Santa Barbara, will investigate how these animals’ carcasses affect their ecosystems. With a three-year grant totaling more than $1.3 million, they will survey Kruger National Park in South Africa, studying the impact of elephant carcasses on the landscape.

“People focus on the role of big animals in ecosystems for obvious reasons. But almost everybody focuses on the role these animals play while they’re alive; their role once they’re dead is really underappreciated,” said Deron Burkepile, an ecology professor at UC Santa Barbara and the project’s principal investigator.

Kruger National Park is about the area of Massachusetts, and among the largest reserves in Africa. Rangers patrol sections of the park and record elephant carcasses, marking the locations with GPS coordinates. They’ve amassed around 30 years of data so far.

In summer 2022, the research team will survey the park by helicopter with the goal of finding 50 carcasses of varying ages in areas with different rain patterns and soil regimes. They’ll begin collecting data the following year to build up their understanding of the communities and conditions around an elephant carcass.

The scientists will sample the soil for nutrients and microbial activity, the plants growing around the body, the bone from the remains themselves, and any animal scat around each site. They also plan to survey the plant and herbivore communities around the site of each carcass. The team will repeat all the surveys and sampling at a control area about 50 meters away from each carcass.

What’s more, the park staff tallies a census of the number and distribution of live elephants on a yearly basis. The scientists also have a good estimate of the animals’ annual mortality rate. With these data, the team can develop a simple model of how many carcasses there should be and where they may be clustered. They can then combine the insights from their fieldwork with the information from the census to create a model showing how elephant carcasses impact the Kruger ecosystem at the landscape scale.

In addition to the researchers at UCSB, the project will include scientists from Utah State University, Marquette University, South African National Parks, and the South African Environment Observation Network. “This research is really only possible because we’re working with people on the ground: The scientists in South Africa in Kruger National Park that have been compiling these data on elephant carcasses,” Burkepile said.

The landscape of Kruger National Park is relatively flat, and its soils are quite old. “They’ve been sitting there exposed — leaching nutrients, weathering and developing for millennia without having enough erosion to bring new resources to the surface,” explained UC Santa Barbara soil scientist Joshua Schimel, who is a co-principal investigator on the project. As a result, the soils are quite nutrient poor.

“A dead elephant is, essentially, one heaping pile of fertilizer,” he continued. In fact, it’s not too different from fortifying a garden. “Bone meal is a standard substance used as an organic fertilizer in a vegetable garden. Bloodmeal for nitrogen and bone meal for phosphorous.”

After an elephant dies, there’s a huge influx of organic carbon, nitrogen and phosphorous as a result of scavenger activity and the decomposition of soft tissues. Despite the flood of nutrients, the site of a fresh elephant carcass can be barren for some time. Scavengers rip up existing vegetation and high levels of nutrients prevent plants from reestablishing.

The influx of nitrogen is actually so intense that it likely makes the area uninhabitable for plants in the short term. “It’s just like when we put too much fertilizer on our tomatoes,” Burkepile said. “Those tomato plants burn. We imagine the same thing would be happening around really fresh elephant carcasses.”

In contrast, the carcass is a windfall for the soil microbiota. “Microbes get first dibs on almost everything,” Burkepile remarked. The researchers anticipate seeing a spike in microbial respiration as the soil bugs feast on the glut of organic carbon and nitrogen. Then, as some of the nitrogen is processed, they expect to see plants recolonize the area.

A carcass actually contains two pools of phosphorus, the researchers explained. Molecules like DNA and ATP in soft tissues will release a quick pulse of the element as the animal decays. Meanwhile, the phosphorous in teeth and bones takes much longer to break down, leading to a more sustained release.

Burkepile expects to see a surge in plant biomass three to four years after the animal’s death, with a peak around five years, once the nitrogen toxicity has declined and phosphorus has begun percolating into the soil. At this point, the process will likely begin affecting the local wildlife directly, especially herbivores.

The extra nutritious patch of land may well attract herbivores from all around, fostering a thriving community. As animals graze and hunt, eat and excrete, they spread seeds and aggregate nutrients from other parts of the savannah. This could then create a feedback loop where elephants frequent these spots to feed, potentially fostering these patches when they ultimately die, Schimel proposed.

As Burkepile put it: “The legacies of these animals don’t stop when they die.”

'I’m melting, melting' — environmentally hazardous coal waste diminished by harmless citric acid

Sandia innovation frees rare-earth metals from coal ash for smartphones, computers

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DOE/SANDIA NATIONAL LABORATORIES

 

IMAGE: A COMPARISON OF SANDIA NATIONAL LABORATORIES METHOD FOR EXTRACTING RARE-EARTH METALS TO EXISTING METHODS SHOWS HOW USING CITRIC ACID IS MORE EFFICIENT. view more 

CREDIT: (IMAGES COURTESY OF GUANGPING XU

In one of nature’s unexpected bounties, a harmless food-grade solvent has been used to extract highly sought rare-earth metals from coal ash, reducing the amount of ash without damaging the environment and at the same time increasing an important national resource.

Coal ash is the unwanted but widely present residue of coal-fired power. Rare-earth metals are used for a variety of high-tech equipment from smartphones to submarines.

The separation method, which uses carbon dioxide, water and food-grade citric acid, is the subject of a Sandia National Laboratories patent application.

“This technique not only recovers rare-earth metals in an environmentally harmless manner but would actually improve environments by reducing the toxicity of coal waste dotting America,” said Guangping Xu, lead Sandia researcher on the project.

“Harmless extraction of rare-earth metals from coal ash not only provides a national source of materials essential for computer chips, smart phones and other high-tech products — including fighter jets and submarines — but also makes the coal ash cleaner and less toxic, enabling its direct reuse as concrete filler or agricultural topsoil,” he said.

The method, if widely adopted, could make coal ash, currently an environmental pariah, into a commercially viable product, Xu said.

Environmentally friendly method for mining rare-earth metals

The most common acids used as chemical separators in mining — nitric, sulfuric or phosphoric acids — also are able to extract rare-earth metals from coal ash but produce large amounts of acid waste, leaving the environment in worse shape than before, Xu said. “Environmentally harmful acids would raise clean-up costs beyond economic feasibility in the United States.”

The Sandia process, which uses citric acid as a carrier for rare-earth metals, so they separate from coal ash, the host material, was implemented by Xu. The extraction process is facilitated by using supercritical carbon dioxide solvent. Xu’s Sandia colleague Yongliang Xiong suggested citric acid, a commonly used and environmentally friendly chemical for holding metals in solution.

Xu found that in less than a day, at 158 degrees Fahrenheit (70 degrees Celsius) and 1,100 pounds per square inch pressure (about 70 times ordinary atmospheric pressure), the method extracted 42% of rare-earth metals present in coal waste samples.

Chinese mines, where 95% of the world’s resources of rare-earth metals are located, achieve less efficient separation while using environmentally damaging methods.

“Theoretically, an American company could use this technique to mine coal and coal byproducts for rare-earth metals and compete with Chinese mining,” said Xu. Furthermore, for U.S. national security purposes “it is probably reasonable to have alternate sources of rare-earth metals to avoid being at the mercy of a foreign supply.”

Detoxifying coal ash for reuse alone should be worth the effort, Xu said. There’s no shortage of coal ash as a raw material. According to a paper published in 2016 in the journal Environmental Science & Technology, “Approximately 115 million metric tons of coal combustion products are generated annually, and this sum includes 45 million tons of fly ash,” the lightest kind of coal ash.

These numbers remain of interest today, said Xu.

“If we don’t detoxify and reuse the coal ash, then it will be abandoned in ponds and landfills and cost billions of dollars to clean up over the long term,” he said. To help make that outcome less likely, “We expect tests of our extraction techniques at larger volumes and on a variety of coal-based sources in the near future.”  

 

CAPTION

Sandia National Laboratories researcher Guangping Xu adds coal ash into a citric acid mixture. This solution will be fed into a reactor — operating at about 70 times atmospheric pressure — where supercritical carbon dioxide aids citric acid in extracting rare-earth metals.

CREDIT

Rebecca Lynne Gustaf

Carbon sequestration also a possibility

This technology also could open a new avenue for carbon-dioxide reutilization and sequestration, said Xu’s Sandia colleague Mark Rigali, who with Xu is exploring the use of citric acid and supercritical carbon dioxide to mine metals from oil and gas shales that are often rich in metals.

“Using existing oil and gas fracking wells, the citric acid and supercritical carbon dioxide can be used cost-effectively to mine metals while disposing of carbon dioxide below ground,” Rigali said.

Subsurface storage of the carbon dioxide should keep it from entering the atmosphere and contributing to climate change, Rigali said.

The work is supported by Sandia’s Laboratory Directed Research and Development program.

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Sandia National Laboratories is a multimission laboratory operated by National Technology and Engineering Solutions of Sandia LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration. Sandia Labs has major research and development responsibilities in nuclear deterrence, global security, defense, energy technologies and economic competitiveness, with main facilities in Albuquerque, New Mexico, and Livermore, California.