Archive for the ‘Global Warming’ Category

Fall black gill cruise rolls out new research

November 10, 2016

The University of Georgia Skidaway Institute of Oceanography entered the fourth year of its black gill research program with a daylong cruise on board the Research Vessel Savannah and the introduction of a new smartphone app that will allow shrimpers to help scientists collect data on the problem.

Led by UGA scientists Marc Frischer, Richard Lee, Kyle Johnsen and Jeb Byers, the black gill study is being conducted in partnership with UGA Marine Extension and Georgia Sea Grant, and is funded by Georgia Sea Grant.

Black gill is a condition Georgia shrimpers first noticed in the mid-1990s. Many shrimpers have blamed black gill for poor shrimp harvests in recent years, but until Frischer began his study, almost nothing was known about the condition. Now the researchers know black gill is caused by a parasite—a single-cell animal called a ciliate—although the exact type of ciliate is still a mystery.

The October cruise had three goals. The first was simply to collect data and live shrimp for additional experiments.

 

“We were able to collect enough live shrimp in good shape to set up our next experiment,” Frischer said. “We are planning on running another direct mortality study to investigate the relationship between temperature and black gill mortality. This time, instead of comparing ambient temperature to cooler temperatures as we did last spring and summer, we will investigate the effects of warming.”

Researchers Marc Frischer (UGA Skidaway Institute), Brian Fluech and Lisa Gentit (both UGA Marine Extension and Georgia Sea Grant) examine shrimp for signs of black gill.

Researchers Marc Frischer (UGA Skidaway Institute), Brian Fluech and Lisa Gentit (both UGA Marine Extension and Georgia Sea Grant) examine shrimp for signs of black gill.

If his hypothesis is correct, Frischer believes researchers would expect that raising fall water temperatures to warmer summer levels in a laboratory setting will induce black gill associated mortality in the shrimp caught in the fall.

Those studies will be compared to those that are being conducted in South Carolina in a slightly different manner. Frischer expects the results should be similar.

“However, as it goes with research, we are expecting surprises,” Frischer continued. “We also collected a good set of samples that will contribute to our understanding of the distribution and impact of black gill.”

A second goal was to introduce and begin field testing a new smartphone application developed by Johnsen. The app is intended to be a tool that will allow shrimp boat captains and recreational shrimpers to assist the researchers by filling some of the holes in the data by documenting the extent of black gill throughout the shrimp season. The Georgia Department of Natural Resources conducts surveys of the shrimp population up and down the coast throughout the year. However, those surveys do not provide the researchers with the rich data set they need to really get an accurate assessment of the black gill problem.

A sample screen shot of the black gill smartphone application.

A sample screen shot of the black gill smartphone application.

“Instead of having just one boat surveying the prevalence of black gill, imagine if we had a dozen, or 50 or a hundred boats all working with us,” Frischer said. “That’s the idea behind this app.”

The fishermen will use the app to document their trawls and report their data to a central database. Using GPS and the camera on their smartphone, they will record the location and images of the shrimp catch, allowing the researchers to see what the shrimpers see. If repeated by many shrimpers throughout the shrimping season, the information would give scientists a much more detailed picture of the prevalence and distribution of black gill.

“The app is complete and available on the app store, but we are still in the testing stages,” Johnsen said. “We want to make sure that it will be robust and as easy to use on a ship as possible before widely deploying it.”

Recruiting, training and coordinating the shrimpers will be the responsibility of UGA Marine Extension and Georgia Sea Grant.

“I think it should be entirely possible to at least have a small group of captains comfortable and ready to start using it when the 2017 season begins,” Frischer said.

Johnsen is excited about the app for what it can provide to the shrimping and research community, but also the implications it has for using apps to involve communities in general.

“There is still work to be done to improve the usability of these systems,” he said. “But I’m confident that we are going to see an increasing number of these ‘citizen science’ applications going forward.”

The final aim of the cruise was to bring together diverse stakeholders, including fishery managers, shrimpers and scientists, to spend the day together and share ideas.

“This was a good venue for promoting cross-talk among the stakeholder groups,” Frischer said. “I had many good conversations and appreciated the opportunity to provide a few more research updates.”

Georgia DNR's Pat Geer sorts through the marine life caught in a trawl net.

Georgia DNR’s Pat Geer sorts through the marine life caught in a trawl net.

Frischer says he thinks the communication and cooperation among the various stakeholder groups has improved dramatically since the beginning of the study. He recalled that when the study began in 2013, tensions were high. Shrimpers were angry and demanded that something be done to address the problem of black gill. Meanwhile, fishery managers were unclear if black gill was even causing a problem and frustrated that no one could provide them any reliable scientific advice. The research community had not been engaged and given the resources to pursue valid investigations.

“In 2016, we still have black gill. The fishery is still in trouble, but it does feel like we are at least understanding a bit more about the issue,” Frischer said. “Most importantly, it is clear that all of us are now working together.

“My feeling is that the opportunity for us to spend a day like that together helps promote understanding, communication and trust among the shrimpers, managers and researchers.”

Advertisements

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.

 

Video — UGA Skidaway Institute scientists complete sea level study on Georgia coast

February 25, 2016

Sea level is projected to rise at least one meter by 2100. Where will that water go and how will it change the Georgia coastal ecosystem? University of Georgia Skidaway Institute of Oceanography scientist Clark Alexander and Georgia Southern University researcher Christine Hladik are attempting to answer those questions.

https://youtu.be/vNFrxb4cytU

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 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.

 

Skidaway Institute’s Elizabeth Harvey embarks on month-long Atlantic cruise

October 27, 2015

UGA Skidaway Institute scientist Elizabeth Harvey will be spending the next month on board Woods Hole’s Research Vessel Atlantis.NAAMESbannerWithSat w

The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) is a five year investigation to resolve key processes controlling ocean system function, their influences on atmospheric aerosols and clouds and their implications for climate.

Here is Dr. Harvey’s first post on the cruise’s blog. 

UGA Skidaway Institute scientist stands atop the globe

September 14, 2015

University of Georgia Skidaway Institute of Oceanography researcher Chris Marsay is on top of the world—literally.

UGA Skidaway Institute scientist Chris Marsay at the North Pole, with the U.S. Coast Guard Cutter Healy in the background.

UGA Skidaway Institute scientist Chris Marsay at the North Pole, with the U.S. Coast Guard Cutter Healy in the background.

Marsay arrived at the North Pole in early September. He is taking part in the US GEOTRACES Arctic Expedition on board the U.S. Coast Guard Cutter Healy, a polar icebreaker.

The project is part of an international, multiple icebreaker effort to conduct geochemical sampling of the Arctic Ocean. The cruise arrived at 90 degrees north on Sept. 5 in what is the first occupation of the North Pole by an unaccompanied U.S. surface ship—submarines usually follow ships below the ice. While at the pole, the Healy rendezvoused with the German ship conducting the German leg of the GEOTRACES Arctic program.

Marsay is working with UGA Skidaway Institute professor Cliff Buck and scientists from Florida State University and Rutgers University. The research team has been funded by the National Science Foundation to collect samples from the atmosphere, precipitation and surface water from melt ponds during the cruise.

Chris Marsay collects samples at the North Pole.

Chris Marsay collects samples at the North Pole.

“Our research goals are to describe the chemistry of atmospheric deposition to the region and quantify flux rates,” Buck said. “These data will then be shared with the scientific community to better understand biogeochemical cycling of trace elements and isotopes in the Arctic Ocean.”

Skidaway researchers “caricaturized”

September 2, 2015

A couple of our researchers, Mike Robinson and LeeAnn DeLeo, made a caricature appearance in an editorial cartoon in the Savannah Morning News this week. Thanks, cartoonist Mark Streeter!Streeter Cartoon

Scientists work to predict 22nd century look of the Georgia coast

August 27, 2015

University of Georgia Skidaway Institute of Oceanography scientist Clark Alexander is working on a project to predict how the Georgia coast—characterized by a complex system of barrier islands, salt marshes, estuaries, tidal creeks and rivers—may look 25, 50 and 100 years from now. As sea level rises over the next century, that picture is changing.

Predictions of sea level rise over the next century vary from the current rate of roughly 30 centimeters—about a foot—to as much as two meters—about 6 feet. Although scientists disagree on the ultimate height of the rise, they all agree that salty water is moving inland and will continue to do so for the foreseeable future, Alexander said. Here on the Georgia coast, islands will become smaller or disappear entirely; salt marshes will be inundated by the rising waters and migrate towards the uplands; and some low-lying uplands will become salt marshes.

To predict the extent of these changes, scientists are using the predictive Sea Level Affecting Marshes Model, or SLAMM, which was originally developed for the U.S. Fish and Wildlife Service.

SLAMM predicts the effects of future sea level rise based on two key inputs: an elevation mapping of the coastal zone and salinity profiles up the rivers and waterways. Salinity and elevation are two key factors that determine the type of plants, and thus habitat, that will be present at any particular location.

“As sea level rises, the fresh water in rivers will be pushed further upstream,” Alexander said. “The brackish and salty water will also move up, and the salt marshes will expand.”

Researcher Mike Robinson adjusts the salinity monitoring equipment while LeAnn DeLeo drives the boat.

Researcher Mike Robinson adjusts the salinity monitoring equipment while LeAnn DeLeo drives the boat.

Funded by a Coastal Incentive Grant from the Georgia Department of Natural Resources Coastal Management Program, Alexander and his team have been studying the five key river systems along the coast and numerous salt marsh estuaries. Salinity along the coast is dominantly affected by river discharge into the estuaries, so the team has been conducting its surveys during both winter—high river flow—and the summer—low river flow—conditions.

“We start at the mouth of a river about an hour before high tide and then we follow that high tide up the river, mapping the surface salinity along the way,” Alexander said. “We find the maximum inshore intrusion of salinity at high tide during a spring tide. That is the location that defines the boundary between the brackish marshes and the freshwater marshes.”

In addition to tracking surface salinity, the researchers also stop periodically and measure the salinity throughout the water column to determine if what they measure at the surface is similar to what is present near the bottom. They lower a device that measures the water conductivity (which is related to salinity), temperature and depth from the surface to the bottom. Also equipped with GPS capability, the device automatically captures the location of every water column profile.

Researcher LeeAnn DeLeo lowers the sensor to measure conductivity, temperature and depth from the surface to the bottom.

Researcher LeeAnn DeLeo lowers the sensor to measure conductivity, temperature and depth from the surface to the bottom.

In many coastal regions, denser, saltier water tends to sink to the bottom and the lighter, fresh water remains near the surface. However, because of the energy produced by Georgia’s wide tidal range, the team found that most of the water on the Georgia coast is well mixed and doesn’t show up as layers.

The second part of the project is to fine-tune existing elevation data. Scientists have an extensive set of elevation information from airplane-mounted Light Detection And Ranging systems. LIDAR is usually very accurate, except in marshes, because it cannot see through the vegetation to the actual ground surface.

“You might be off by 30 centimeters or more, and in a low-lying, flat area like our coastal zone, that can make a big difference in predicting where the water will flood,” Alexander said.

The Skidaway Institute team is working with Georgia Southern University scientist Christine Hladik on a fix. By comparing LIDAR data with the true elevation in a particular area, Hladik observed that the LIDAR error varied according to the type of plants growing there. For example, if the area contained the dense, tall spartina, the error was large and, on average, a consistent number of centimeters. If the region was covered with a different, less-dense-growing salt marsh plant, like short spartina, the error was smaller but also consistent.

“She discovered that if you know what type of vegetation is covering a section of marshland, you can plug in the correction and come back with an accurate measure of the elevation,” Alexander said.

The research team observed the vegetation and measured the true ground level at 400 randomly selected points throughout coastal brackish and salt marshes in Georgia. That information and knowledge of plant types is being used to correct the existing marsh elevations.

The research team will complete one more set of river surveys before the project ends in September. Alexander hopes to obtain continued funding to use this newly acquired elevation and salinity data in a fresh SLAMM model run for the Georgia coast, using all the high-resolution data developed in this project.

“We should be able to look out as much as 100 years in the future and see where the different wetlands will be by then,” he said. “That way we can plan for marsh sustainability, retreat and sea level rise.”