Archive for the ‘Research Paper’ Category

UGA Skidaway Institute research paper selected for Research Spotlight

February 3, 2017

 

Skidaway Institute's Aron Stubbins

Skidaway Institute’s Aron Stubbins

A research paper by University of Georgia Skidaway Institute of Oceanography scientist Aron Stubbins has been selected by the Journal of Geophysical Research-Biogeosciences to be featured as a Research Spotlight on the journal’s website and in the magazine Eos. Research Spotlights summarize the the best accepted articles for the Earth and space science community.

Stubbins’s paper, titled “Low photolability of yedoma permafrost dissolved organic carbon,” followed-up on earlier research into a massive store of carbon—relics of long-dead plants and other living things—preserved within ancient Arctic permafrost. That research showed the long-frozen permafrost is thawing, and the organic material it has preserved for tens of thousands of years is now entering the environment as dissolved organic matter in streams and rivers. Bacteria are converting the organic material into carbon dioxide, which is being released into the atmosphere.

A bank of permafrost thaws near the Kolyma River in Siberia

A bank of permafrost thaws near the Kolyma River in Siberia

The current paper examines the effect of sunlight on the dissolved carbon compounds. The researchers discovered that sunlight changes the chemistry of the permafrost carbon, however sunlight alone does not convert the permafrost carbon to carbon dioxide. The researchers concluded the decomposition of organic materials via bacteria is mostly likely the key process for converting permafrost carbon within rivers into carbon dioxide.

The research team includes co-lead author Robert Spencer of Florida State University; co-authors Leanne Powers and Thais Bittar from UGA Skidaway Institute; Paul Mann from Northumbria University; Thorsten Dittmar from Carl von Ossietzky University of Oldenburg; Cameron McIntyre from the Scottish Universities Environmental Research Centre; Timothy Eglinton from ETH Zurich; and Nikita Zimov from the Russian Academy of Science.  While climatologists are carefully watching carbon dioxide levels in the atmosphere, another group of scientists is exploring a massive storehouse of carbon that has the potential to significantly affect the climate change picture.

 

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UGA Skidaway Institute associate professor cited for top research articles

December 2, 2016

University of Georgia Skidaway Institute of Oceanography associate professor Aron Stubbins is one of just a handful of researchers cited in the journal Limnology and Oceanography for authoring two of the journal’s top scientific papers over the past 60 years.

Skidaway Institute's Aron Stubbins

Skidaway Institute’s Aron Stubbins

Limnology and Oceanography is an official publication of the Association for the Sciences of Limnology and Oceanography and is considered a premier scientific journal. In its recently published 60th anniversary issue, the journal collected and republished the 10 most cited research papers for each of the last six decades. Stubbins authored or co-authored two of those papers, one in 2008 and the other in 2010.

“It came as quite a surprise to see two articles show up on the list,” Stubbins said. “I was at a conference and wasn’t really checking my email when one of my colleagues let me know.”

The journal used the number of times a paper was cited in future studies as the yardstick to determine which papers should be included on the list. It is one commonly used method for measuring the impact of a scientist’s work.

“The list isn’t really about popularity,” Stubbins said. “It’s about usefulness. That people have found some of my work useful over the years is rewarding.”

The 2008 paper was titled “Absorption spectral slopes and slope ratios as indicators of molecular weight, source, and photobleaching of chromophoric dissolved organic matter.” The lead author was John Helms. Stubbins was a co-author along with four other scientists. The research team developed a new method for extracting new information from a relatively common and simple test of the color of dissolved organic matter.

Stubbins was the lead author, along with nine co-authors, of the second paper, “Illuminated darkness: Molecular signatures of Congo River dissolved organic matter and its photochemical alteration as revealed by ultrahigh precision mass spectrometry.” The study examined organic carbon carried to the ocean by the Congo River — after the Amazon, the second largest river in the world in terms of carbon and water flow. The research team studied how sunlight degrades organic material, including which compounds are degraded, which are not and what new compounds are created when sunlight shines on river water.

“His inclusion in this seminal volume is quite an honor for Dr. Stubbins,” UGA Skidaway Institute Interim Director Clark Alexander said. “This recognition validates what we have always known, that he is conducting groundbreaking and meaningful research that is recognized around the world.”

All 60 papers can be found at http://aslopubs.onlinelibrary.wiley.com/.

 

Molecular-level relationships key to deciphering ocean carbon

March 9, 2016

Athens, Ga. – From beach shallows to the ocean depths, vast numbers of chemical compounds work together to reduce and store atmospheric carbon in the world’s oceans.

 In the past, studying the connections between ocean-borne compounds and microbes has been impractical because of the sheer complexity of each. Three University of Georgia faculty members—along with an international team of scientists—bring to the forefront technological developments that are providing scientists with the analytical tools needed to understand these molecular-level relationships.

 Their perspective article appears March 7 in the Proceedings of the National Academy of Sciences. It focuses on dissolved organic matter, or DOM, in the world’s oceans as a central carbon reservoir in the current and future global carbon cycle.

Skidaway Institute's Aron Stubbins

Skidaway Institute’s Aron Stubbins

 “Dissolved organic carbon is an amazing and confounding molecular soup,” said Aron Stubbins, co-author and associate professor of marine sciences at UGA housed at the Skidaway Institute of Oceanography in Savannah. “It sits at the center of the ocean carbon cycle, directing the energy flow from the tiny plants of the sea, phytoplankton, to ocean bacteria. Though around a quarter of all the sunlight trapped by plants each year passes through dissolved organic carbon, we know very little about the chemistry of the molecules or the biology of the bacterial players involved.”

 The carbon the microbes process is stored in seawater in the form of tens of thousands of different dissolved organic compounds.

 Researchers thought they had a handle on how some aspects of the process works, but “a number of new studies have now fundamentally changed our understanding of the ocean carbon cycle,” said the paper’s lead author Mary Ann Moran, Distinguished Research Professor at UGA.

 In the context of methodological and technological innovations, the researchers examine several questions that illustrate how new tools—particularly innovations in analytical chemistry, microbiology and informatics—are transforming the field.

 From how different major elements have cycles linked though marine dissolved organic matter to how and why refractory organic matter persists for thousands of years in the deep ocean to the number of metabolic pathways necessary for microbial transformation, the article infers a scale of enhanced and expanded understanding of complex processes that was previously impractical.

 The perspective article, Deciphering Ocean Carbon in a Changing World,” was shaped in discussions at a 2014 workshop supported by the Gordon and Betty Moore Foundation and Microsoft Research Corporation. Moran’s research has been supported by the Gordon and Betty Moore Foundation’s Marine Microbiology Initiative.

 Co-authors on the paper include UGA’s Patricia Medeiros, assistant professor in the department of marine sciences. Others involved are with the Woods Hole Oceanographic Institute; the Scripps Institute of Oceanography and the Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego; University of Tennessee, Knoxville; Oregon State University; Columbia University; The Pacific Northwest National Laboratory, Richland Washington; the University of Washington; University of Oldenburg, Germany; Sorbonne Universités; and the University of Chicago.

 Writer: Alan Flurry, 706-542-3331, aflurry@uga.edu

Contacts: Mary Ann Moran, 706-542-6481, mmoran@uga.edu; Patricia Medeiros, 706-542-6744, medeiros@uga.edu; Aron Stubbins, 912-598-2320, aron.stubbins@skio.uga.edu

 

 

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This release is online at http://news.uga.edu/releases/article/molecular-level-relationships-ocean-carbon/.

Climate change likely to increase black carbon input to the Arctic Ocean

November 30, 2015

University of Georgia Skidaway Institute of Oceanography scientist Aron Stubbins led a team of researchers to determine the levels of black carbon in Arctic rivers and found that the input of black carbon to the Arctic Ocean is likely to increase with global warming. The results of their study were recently published in the journal Frontiers in Earth Science.

Black carbon, or biochar, is formed when vegetation and other organic matter burns. Today black carbon is a massive store of carbon in global soils, where it is thought to be very stable — so stable, that researchers have previously suggested that adding black carbon to soils might be a good way to lock away carbon dioxide and reduce climate change. This new research reveals that the black carbon stored in Arctic soils is being exported to the oceans.

Arctic rivers are the major way black carbon is transported to the ocean.

Arctic rivers are the major way black carbon is transported to the ocean.

The Arctic is warming faster than other regions of the planet due to climate change. The scientists report that, as the planet warms, the amount of black carbon transported to the Arctic Ocean will likely increase. Once dissolved in the ocean and exposed to sunlight, black carbon may be rapidly converted back to the greenhouse gas carbon dioxide.

In ongoing work at UGA and partner universities, Stubbins and his colleagues are trying to determine just how much black carbon will be exported to the Arctic Ocean as the Arctic continues to warm, and once it reaches the oceans, what percentage will reach the atmosphere as carbon dioxide.

The article is titled “Utilizing Colored Dissolved Organic Matter to Derive Dissolved Black Carbon Export by Arctic Rivers.” In addition to Stubbins, the co-authors include Robert Spencer from Florida State University; Jutta Niggemann and Thorsten Dittmar from the University of Oldenburg, Germany; Paul Mann from Northumbria University; Max R. Holmes from Woods Hole Research Center; and James McClelland from University of Texas Marine Science Institute.

The entire article can be viewed online at: http://journal.frontiersin.org/article/10.3389/feart.2015.00063/abstract

Stubbins has a website detailing this and other work on black carbon at:

http://www.skio.usg.edu/?p=research/chem/biogeochem/blkcarbon

Skidaway scientist’s study front-cover news

November 2, 2015

Aron Stubbins’ recent work on deep-ocean hydrothermal vents (earlier post) is the cover story for this month’s Nature Geoscience. Wayi to go, Aron!

Aron Cover

Skidaway Institute scientist explores deep-sea hydrothermal vents

October 29, 2015

OLYMPUS DIGITAL CAMERAUniversity of Georgia Skidaway Institute of Oceanography scientist Aron Stubbins joined a team of researchers to determine how hydrothermal vents influence ocean carbon storage. The results of their study were recently published in the journal Nature Geoscience.

Hydrothermal vents are hotspots of activity on the otherwise dark, cold ocean floor. Since their discovery, scientists have been intrigued by these deep ocean ecosystems, studying their potential role in the evolution of life and their influence upon today’s ocean.

Stubbins and his colleagues were most interested in the way the vents’ extremely high temperatures and pressure affect dissolved organic carbon. Oceanic dissolved organic carbon is a massive carbon store that helps regulate the level of carbon dioxide in the atmosphere—and the global climate.

Photo Credit: NOAA Okeanos Explorer Program, INDEX-SATAL 2010

Photo Credit: NOAA Okeanos Explorer Program, INDEX-SATAL 2010

Originally, the researchers thought the vents might be a source of the dissolved organic carbon. However, their research showed just the opposite.

Lead scientist Jeffrey Hawkes, currently a post-doctoral fellow at Uppsala University in Sweden, directed an experiment in which the researchers heated water in a laboratory to 380 degrees Celsius, 716 degrees Fahrenheit, in a scientific pressure cooker to mimic the effect of ocean water passing through hydrothermal vents.

The results revealed that dissolved organic carbon is efficiently removed from ocean water when heated. The organic molecules are broken down and the carbon converted to carbon dioxide.

The entire ocean volume circulates through hydrothermal vents about every 40 million years. This is a very long time, much longer than the timeframes over which current climate change is occurring, Stubbins explained. It is also much longer than the average lifetime of dissolved organic molecules in the ocean, which generally circulate for thousands of years, not millions.

“However, there may be extreme survivor molecules that persist and store carbon in the oceans for millions of years,” Stubbins said. “Eventually, even these hardiest of survivor molecules will meet a fiery end as they circulate through vent systems.”

Hawkes conducted the work while at the Research Group for Marine Geochemistry, University of Oldenburg, Germany. The study’s co-authors also included Pamela Rossel and Thorsten Dittmar, University of Oldenburg; David Butterfield, University of Washington; Douglas Connelly and Eric Achterberg, University of Southampton, United Kingdom; Andrea Koschinsky, Jacobs University, Germany; Valerie Chavagnac, Université de Toulouse, France; and Christian Hansen and Wolfgang Bach, University of Bremen, Germany.

The study on “Efficient removal of recalcitrant deep-ocean dissolved organic matter during hydrothermal circulation” is available at http://www.nature.com/ngeo/journal/v8/n11/full/ngeo2543.html.

 

Warming climate may release vast amounts of carbon from long-frozen Arctic soils

April 24, 2015

While climatologists are carefully watching carbon dioxide levels in the atmosphere, another group of scientists is exploring a massive storehouse of carbon that has the potential to significantly affect the climate change picture.

Aron Stubbins

Aron Stubbins

University of Georgia Skidaway Institute of Oceanography researcher Aron Stubbins is part of a team investigating how ancient carbon, locked away in Arctic permafrost for thousands of years, is now being transformed into carbon dioxide and released into the atmosphere. The results of the study were published in Geophysical Research Letters.

The Arctic contains a massive amount of carbon in the form of frozen soil—the remnants of plants and animals that died more than 20,000 years ago. Because this organic material was permanently frozen year-round, it did not undergo decomposition by bacteria the way organic material does in a warmer climate. Just like food in a home freezer, it has been locked away from the bacteria that would otherwise cause it to decay and be converted to carbon dioxide.

“However, if you allow your food to defrost, eventually bacteria will eat away at it, causing it to decompose and release carbon dioxide,” Stubbins said. “The same thing happens to permafrost when it thaws.”

Scientists estimate there is more than 10 times the amount of carbon in the Arctic soil than has been put into the atmosphere by burning fossil fuels since the start of the Industrial Revolution. To look at it another way, scientists estimate there is two and a half times more carbon locked away in the Arctic deep freezer than there is in the atmosphere today. Now, with a warming climate, that deep freezer is beginning to thaw and that long-frozen carbon is beginning to be released into the environment.

“The study we did was to look at what happens to that organic carbon when it is released,” Stubbins said. “Does it get converted to carbon dioxide or is it still going to be preserved in some other form?”

Stubbins and his colleagues conducted their fieldwork at Duvanni Yar in Siberia. There, the Kolyma River carves into a bank of permafrost, exposing the frozen organic material. This worked well for the scientists, as they were able to find streams that consisted of 100 percent thawed permafrost. The researchers measured the carbon concentration, how old the carbon was and what forms of carbon were present in the water. They bottled it with a sample of the local microbes. After two weeks, they measured the changes in the carbon concentration and composition and the amount of carbon dioxide that had been produced.

A bank of permafrost thaws near the Kolyma River in Siberia.

“We found that decomposition converted 60 percent of the carbon in the thawed permafrost to carbon dioxide in two weeks,” Stubbins said. “This shows the permafrost carbon is definitely in a form that can be used by the microbes.”

Lead author Robert Spencer of Florida State University added, “Interestingly, we also found that the unique composition of thawed permafrost carbon is what makes the material so attractive to microbes.”

The study also confirmed what the scientists had suspected: The carbon being used by the bacteria is at least 20,000 years old. This is significant because it means that carbon has not been a part of the global carbon cycle in the recent past.

“If you cut down a tree and burn it, you are simply returning the carbon in that tree to the atmosphere where the tree originally got it,” Stubbins said. “However, this is carbon that has been locked away in a deep-freeze storage for a long time.

“This is carbon that has been out of the active, natural system for tens of thousands of years. To reintroduce it into the contemporary system will have an effect.”

The carbon release has the potential to create what scientists call a positive feedback loop. This means as more carbon is released into the atmosphere, it would amplify climate warming. That, in turn, would cause more permafrost to thaw and release more carbon, causing the cycle to continue.

“Currently, this is not a process that shows up in future (Intergovernmental Panel on Climate Change) climate projections; in fact, permafrost is not even accounted for,” Spencer said.

“Moving forward, we need to find out how consistent our findings are and to work with a broader range of scientists to better predict how fast this process will happen,” Stubbins said.

In addition to Stubbins and Spencer, the research team included Paul Mann from Northumbria University, United Kingdom; Thorsten Dittmar from the University of Oldenburg, Germany; Timothy Eglinton and Cameron McIntyre from the Geological Institute, Zurich, Switzerland; Max Holmes from Woods Hole Research Center; and Nikita Zimov from the Far-Eastern Branch of the Russian Academy of Science.

Skidaway Institute intern wins research prize

July 16, 2014

Candy v wAn undergraduate student who conducted her research at the University of Georgia Skidaway Institute of Oceanography will attend a prestigious international science conference as a reward for winning the Outstanding Research Paper in the Savannah State University’s Bridge to Research program.

Candilianne Serrano Zayas’ paper was chosen from 10 others and tied for first place. She will attend the international science conference sponsored by the Association for the Sciences of Limnology and Oceanography meeting in Granada, Spain, in February 2015.

Zayas is a rising junior and biology major at the Universidad Metropolitana in San Juan, Puerto Rico. Her research project studied the microbiological community present in dolphins.

“One of the reasons this is important is because bottlenose dolphins are a marine sentinel species,” Zayas said. “This means that their health can be indicative of the health of the overall environment, which in the case of dolphins is our coastal waters.”

Zayas believes what made her project special was that it involved both field and lab work, and it created an interesting and important relationship between human health and animal health. “You don’t need to take a molecular biology class to understand how it works, so it makes it so much easier to explain to different audiences.”

Zayas worked in the lab of Skidaway Institute professor Marc Frischer, who praised her and her mentors.

“The combination of a good student, an appropriate project and, most importantly, a stellar mentor shoots these students to the stars,” Frischer said.

Zayas was mentored by SSU graduate student Kevin McKenzie, who is also a member of the Frischer research team. Zayas echoed Frischer’s praise. “Kevin took the time to explain it all to me, even two or three times, and he taught me everything I did on this project,” she said.

In the 2013, McKenzie mentored another REU student who also won this prestigious award. Kristopher Drummond, an SSU student and star football player for SSU, has continued the research he started and plans to continue his studies.

Zayas says she plans to complete her bachelor’s degree in Puerto Rico and then attend graduate school.

Zayas shared the first place honor with SSU student Darius Sanford, who worked at Gray’s Reef National Marine Sanctuary and who will also attend the ASLO meeting.

Launched in 2009, the SSU Bridge to Research in Marine Sciences program is a National Science Foundation-funded Research Experience for Undergraduates program. The SSU program has proven successful in inspiring under-represented student populations to pursue degrees and careers in science and technology-based research fields.

“African-Americans are greatly underrepresented in the ocean sciences,” SSU professor Tara Cox explained. “Of the 28 students who have completed the program, 20 are African-American.”

The seven-week 2014 Bridge to Research program began with field trips and classroom work covering research basics. The students then took a two-day research cruise on Skidaway Institute’s Research Vessel Savannah. They then were paired with a mentor at one of the participating organizations—Savannah State University, UGA Skidaway Institute of Oceanography, Gray’s Reef National Marine Sanctuary or Georgia Tech-Savannah. During this partnership, they conducted research and then presented it at a public forum.

Skidaway Institute professor nominated for award

September 19, 2013

Marc Frischer

Marc Frischer

A paper published by University of Georgia Skidaway Institute of Oceanography professor Marc Frischer has been nominated for the James LaBounty Award as the best paper published during the past year in the scientific journal, Lake and Reservoir Management. Published by the North American Lake Management Society, the journal features peer-reviewed scientific papers targeting a largely technical audience of academics and lake managers. 

 The article, “Accuracy and reliability of Dreissena spp. larvae detection by cross-polarized light microscopy, imaging flow cytometry, and polymerase chain reaction assays” described an experiment to assess the reliability of three different methods for detecting zebra and quagga mussel larvae.

 Native to the lakes of southern Russia, zebra and quagga mussels have become a troublesome invasive species in North America. They disrupt ecosystems, and damage harbors and waterways, ships and boats, and water treatment and power plants. The goal of the study was to provide quantitative data useful for managers struggling to contain the current spread of these species in the western U.S.

 The manuscript was co-authored by Kevin Kelly from the U.S. Bureau of Reclamation Environmental Applications and Research Group, and Sandra Nierzwicki-Bauer from the Darrin Fresh Water Institute and Rensselaer Polytechnic Institute. The study was funded by the U.S. Fish and Wildlife Servce.

An abstract of the article is available at http://dx.doi.org/10.1080/07438141.2012.731027.

 According to the journal editor, Ken Wagner, the nomination means the editorial board felt that the paper was one of the more important contributions to Lake and Reservoir Management this past year.

 The final award will be presented at the annual symposium of the North American Lake Management Society in San Diego in October.

 For more information on the ongoing invasion and management efforts, see http://www.musselmonitoring.com.