Posts Tagged ‘carbon’

UGA Skidaway Institute scientists study role of sunlight on marine carbon dioxide production

July 21, 2016

Scientists at the University of Georgia Skidaway Institute of Oceanography have received a $527,000 grant from the National Science Foundation Chemical Oceanography Program to answer one of the long-standing questions about carbon in the ocean—the rate sunlight produces carbon dioxide from organic carbon molecules in the sea.

Jay Brandes, Leanne Powers and Aron Stubbins will use a new technique they developed to measure this process, which is known as photo-degradation.

Researchers Aron Stubbins (l) and Jay Brandes

Researchers Aron Stubbins (l) and Jay Brandes

The ocean is full of millions of different types of organic compounds. Some are consumed by bacteria, but many are not easily consumed and remain in the ocean for hundreds or thousands of years. However, near the surface, sunlight causes the breakdown of organic compounds and converts them into carbon dioxide through photo-degradation. Until recently, this process has been nearly impossible to measure directly in most of the ocean because the additional carbon dioxide produced per day is tiny compared to the existing high concentration of CO2 present in the sea.

Researcher Leanne Powers

Researcher Leanne Powers

Brandes described the problem as looking for a needle in a haystack.

“You might think this is not important because it is hard to measure, but that’s not true,” he said. “We’re talking about a process that takes place across the whole ocean. When you integrate that over such a vast area, it becomes a potentially very important process.”

The project became possible when the team developed a new technique to measure the change in CO2 concentration in a seawater sample. The concept was the brainchild of Powers, a Skidaway Institute post-doctoral research associate. The technique uses carbon 13, a rare, stable isotope of carbon that contains an extra neutron in its nucleus. Researchers will add a carbon 13 compound to a sample of seawater and then bombard the sample with light. The scientists will then use an instrument known as an isotope ratio mass spectrometer to measure the changes in CO2 concentration.

According to Brandes, this project will be breaking new ground in the field of chemical oceanography.

“We don’t know what the photo-degradation rates are in most of the ocean,” he said. “We are going to establish the first numbers for that.”

The team plans to take samples off the Georgia coast, as well as from Bermuda and Hawaii.

While they will continue to refine the carbon 13 technique, Brandes said it is now time to put that tool to work.

“It is now a matter of establishing what the numbers are in these different locations and trying to develop a global budget,” he said. “Just how much dissolved organic carbon is removed and converted to CO2 every year?”

The project is funded for three years. The team will also create an aquarium exhibit at the UGA Aquarium on the Skidaway Island campus to help student groups and the public understand river and ocean color.

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VIDEO – The climate change issue you probably haven’t heard about

July 6, 2016

The soil in the Arctic holds a massive store of carbon. These remnants of plants and animals that lived tens of thousands of years ago have been locked in permafost, soil that is always frozen…until now.

UGA Skidaway Institute of Oceanography scientist Aron Stubbins is part of a team that travelled to Siberia to discover what happens to that carbon when the permafrost thaws.

 

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/.

Skidaway Institute Arctic carbon research gets additional exposure

January 27, 2016

The Website Environmental Monitor published a good article on some of the work Skidaway Institute scientist Aron Stubbins has been conducting on carbon in black carbon in the Arctic. OLYMPUS DIGITAL CAMERA

http://www.fondriest.com/news/arctic-ocean-biochar-could-increase-with-global-warming.htm

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.

 

Editorial: Skidaway Institute a quiet resource

August 17, 2015

The Savannah Morning News published a very nice editorial about UGA Skidaway Institute today. 

http://savannahnow.com/opinion/2015-08-16/editorial-skidaway-institute-quiet-resource

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.

UGA Skidaway Institute researchers complete ‘26 Hours on the Marsh’

July 30, 2014

Pitching a tent in the woods and fighting off mosquitos may not sound like logistics of a typical oceanography experiment, but that is how researchers at the University of Georgia Skidaway Institute of Oceanography completed an intensive, round-the-clock sampling regimen this month. The project, dubbed “26 Hours on the Marsh” was designed to investigate how salt marshes function and interact with their surrounding environment—specifically how bacteria consume and process carbon in the marsh.

The team set up a sampling station and an outdoor laboratory on a bluff overlooking the Groves Creek salt marsh on the UGA Skidaway Institute campus. The scientists collected and processed water samples from the salt marsh every two hours, beginning at 11 a.m. on July 16 and running through 1 p.m. July 17. By conducting the tests for a continuous 26 hours, the team can compare the samples collected during the day with those collected at night, as well as through two full tidal cycles.

The UGA Skidaway Institute team processes water samples at their outdoor laboratory. (l-r) Megan Thompson, John DeRosa (UGA Intern), Zachary Tait and Dylan Munn (UGA Intern.)

The UGA Skidaway Institute team processes water samples at their outdoor laboratory. (l-r) Megan Thompson, John DeRosa (UGA Intern), Zachary Tait and Dylan Munn (UGA Intern.)

“We wanted to be able to compare not only what is happening to the carbon throughout the tidal cycle, but also what the microbes are doing at high and low tides and also during the day and night,” said Zachary Tait, a UGA Skidaway Institute research technician. “So we had to have two high tides and two low tides and a day and night for each. That works out to about 26 hours.”

The research team ran more than 30 different tests on each sample. The samples will provide data to several ongoing research projects. A research team from the University of Tennessee also participated in the sampling program. Their primary focus was to identify the bacterial population using DNA and RNA analysis.

This sampling project is one of many the researchers conduct during the year. They use an automatic sampling system for most of the other activities. The automatic system collects a liter of water every two hours, and holds it to be collected and processed at the end of the 26-hour cycle. The team could not use the auto sampler this time for several reasons; the scientists needed to collect much more water in each sample than the auto sampler could handle and the auto sampler tends to produce bubbles in the water, so it is not effective for measuring dissolved gasses.

Megan Thompson supervises Dan Barrett (l) and John DeRosa, both UGA interns, as they process samples in a UGA Skidaway Institute laboratory.

Megan Thompson supervises Dan Barrett (l) and John DeRosa, both UGA interns, as they process samples in a UGA Skidaway Institute laboratory.

“The UT scientists wanted to conduct enzyme analysis as well as RNA and DNA tests on the samples, and for those, the samples must be very fresh,” said Megan Thompson, a UGA Skidaway Institute research technician. “You can’t just go out and pick them up the next day.”

About a dozen scientists and students were involved in the project, including Thompson, Tait, a group of undergraduate students completing summer internships at UGA’s Skidaway Institute and a similar group from UT. They split their time between the tent and outdoor laboratory on a bluff overlooking Groves Creek, and the UGA Skidaway Institute laboratories a mile away.

“It was an interesting experience, and I think it went very well,” said Thompson. “However, when we wrapped it up, we were all ready to just go home and sleep.”

“26 Hours on the Marsh” is supported by two grants from the National Science Foundation, totaling $1.7 million that represent larger, three-year, multi-institutional and multi-disciplinary research projects into salt marsh activity. These projects bring together faculty, students and staff from UGA’s Skidaway Institute, UT and Woods Hole Research Center. UGA Skidaway Institute scientists include principal investigator Jay Brandes; chemical oceanographers Aron Stubbins and Bill Savidge; physical oceanographers Dana Savidge, Catherine Edwards and Jack Blanton; and geologist Clark Alexander. Additional investigators include microbial ecologist Alison Buchan and chemical oceanographer Drew Steen, both from UT; as well as geochemist Robert Spencer from WHRC.