Posts Tagged ‘biology’

UGA Skidaway Institute scientists study dynamic Cape Hatteras waters

April 5, 2016

 

Sometimes called the “graveyard of the Atlantic” because of the large number of shipwrecks there, the waters off of Cape Hatteras on the North Carolina coast are some of the least understood on the U.S. eastern seaboard. University of Georgia Skidaway Institute of Oceanography scientist Dana Savidge is leading a team, which also includes UGA Skidaway Institute scientist Catherine Edwards, to investigate the dynamic forces that characterize those waters.

The four-year project, informally called PEACH: Processes driving Exchange at Cape Hatteras, is funded by $5 million grant from the National Science Foundation. Skidaway Institute will receive $1.2 million for its part.

UGA Skidaway Institute scientists Dana Savidge (l) and Catherine Edwards

UGA Skidaway Institute scientists Dana Savidge (l) and Catherine Edwards

Two opposing deep ocean currents collide at Cape Hatteras, making the Atlantic Ocean near there highly dynamic. The warm Gulf Stream hugs the edge of the continental shelf as it flows north from the tip of Florida.  At Cape Hatteras, it opposes a colder current, the Slope Sea Gyre current, that moves southward along the mid-Atlantic coast and breaks away from the coast toward northern Europe. As in the deep ocean, the cool shelf waters of the mid-Atlantic continental shelf meet the warm salty shelf waters from the south at Cape Hatteras.

The convergence of all of these currents at one place means that, after long lifetimes in the sunlit shallow shelves, these waters may export large quantities of organic carbon—small plants and animals that have grown up on the shelf—to the open ocean. Scientists have little understanding of the details of how that happens and how it is controlled by the high-energy winds, waves and interaction the between the constantly changing Gulf Stream and Slope Sea Gyre currents.Cape Hatteras Project Map 2 w

According to Savidge, the area is very difficult to observe because the water is shallow, the sea-state can be challenging and the convergence of strong currents at one place make it hard to capture features of interest.

“It’s difficult to get enough instruments in the water because conditions change rapidly over short distances, and it’s hard to keep them there because conditions are rough,” she said. “Ships work nicely for many of these measurements, but frequently, the ships get chased to shore because of bad weather.”

To overcome the limitations of ship-based work, the research team will use a combination of both shore- and ocean-based instruments to record the movement and characteristics of the streams of water. A system of high-frequency radar stations will monitor surface currents on the continental shelf all the way out to the shoreward edge of the Gulf Stream, providing real-time maps of surface currents.

“Measuring surface currents remotely with the radars is a real advantage here,” Savidge said. “They cover regions that are too shallow for mobile vehicles like ships to operate while providing detailed information over areas where circulation can change quite dramatically over short times and distances.”

Edwards will lead a robotic observational component in which pairs of autonomous underwater vehicles called gliders will patrol the shelf to the north and south of Cape Hatteras.  Packed with instruments to measure temperature, salinity, dissolved oxygen and bio-optical properties of the ocean, both shelf- and deep-water gliders fly untethered through the submarine environment, sending their data to shore at regular intervals via satellite.

To compensate for the notoriously difficult conditions, Edwards will take advantage of a novel glider navigation system she developed with students and collaborators at Georgia Tech that automatically adjusts the glider mission based on ocean forecasts as well as data collected in real time.

“Our experiments show that we can keep the gliders where they need to be to collect the data we need,” she said. “The best part is that we get to put the maps of surface currents together with the subsurface information from the gliders, and we can make all of this information available in real time to scientists, fishermen and the general public.”

The researchers will also place a number of moorings and upward-pointing echo sounders on the sea floor. These acoustic units will track the water movement while also recording temperature and density.  PEACH will focus primarily on the physics of the ocean, but the information the researchers gather will also help scientists more fully understand the chemistry and biology, and may cast light on issues like carbon cycling and global climate change.

“Everyone is interested in the global carbon budget, and the effect of the coastal seas on that budget is not well understood,” Savidge said. “For example, many scientists consider the continental shelf to be a sink for carbon, because there is a lot of biology going on and it draws in carbon.

“However, there are indications that the shelf south of Hatteras is both a sink and a source of carbon. This project may help clarify that picture.”

The project will run through March 2020. The remaining members of the research team are Harvey Seim and John Bane of the University of North Carolina; Ruoying He of North Carolina State University; and Robert Todd, Magdalena Andres and Glen Gawarkiewicz from Woods Hole Oceanographic Institute.

 

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Elizabeth Harvey joins Skidaway Institute faculty

September 3, 2015

OLYMPUS DIGITAL CAMERABiological oceanographer Elizabeth Harvey has joined the faculty of the University of Georgia Skidaway Institute of Oceanography as an assistant professor.

Harvey received her bachelor’s degree in marine science from the University of Maine and a master’s in environmental science from Western Washington University. She earned her doctorate in oceanography from the University of Rhode Island. Immediately prior to joining Skidaway Institute, she completed a post-doctoral fellowship at Woods Hole Oceanographic Institution.

Harvey’s research focus is on the mechanisms of mortality in the planktonic environment in the ocean and how that influences food web structure and biogeochemical cycling.

Skidaway Institute scientist shares Gulf oil spill research grant

December 17, 2014

University of Georgia Skidaway Institute of Oceanography scientist Catherine Edwards is part of a research team that has received an $18.8 million grant to continue studies of natural oil seeps and track the impacts of the BP/Deepwater Horizon oil spill in the Gulf of Mexico ecosystem.

Known as ECOGIG-2 or “Ecosystem Impacts of Oil and Gas Inputs to the Gulf,” the project is a collaborative, multi-institutional effort involving biological, chemical, geological and chemical oceanographers led by the University of Georgia’s Samantha Joye. The research team has worked in the Gulf since the weeks following the 2010 Macondo well blowout.

The three-year, $18.8 million ECOGIG-2 program was funded by the Gulf of Mexico Research Initiative, or GoMRI.

“Our goal is to better understand the processes that have affected the oil spill since 2010,” Edwards said. “How the droplets were dispersed? Where the oil went? How it was taken up by small microbes and also the effects on animals further up the food chain?”

Skidaway Institute scientist Catherine Edwards adjusts a glider’s buoyancy with graduate students Sungjin Cho and Dongsik Chan.

Skidaway Institute scientist Catherine Edwards adjusts a glider’s buoyancy with graduate students Sungjin Cho and Dongsik Chan.

Edwards’ role in the project is to use autonomous underwater vehicles, also called “gliders,” to collect data on conditions around the spill site. Equipped with sensors to measure characteristics such as depth, water temperature, salinity and density, the gliders can cruise the submarine environment for weeks at a time, collecting data and transmitting it back to a ship or a shore station.

“We want to understand the ocean currents—how they change over time and how they change in depth,” Edwards said. “Surface measurements give us a two-dimensional picture of the ocean. Glider data in the vertical provides more valuable information for more fully understanding ocean currents and how they arise.”

The gliders will operate both in conjunction with shipboard instruments and also independently. One advantage of using the gliders is they can operate during storms and rough weather, when it may not be possible to use ships. Edwards said shipboard work doesn’t always give a full picture of ocean dynamics simply by the fact that they can only go out when the weather is reasonably clear.

When working in conjunction with research ships, the gliders can provide additional observations, significantly improving the quality of the data set. The gliders also report dissolved oxygen concentrations and optical measurements of chlorophyll and organic matter, and may also be used as a test vehicle for new instruments in development.

Edwards will use “GENIoS,” a new software package, to help navigate the gliders. GENIoS uses high-resolution forecast models of wind and ocean currents, along with information from the glider itself, to calculate the optimal path for the gliders. This will improve the quality of the scientific data collected.

GENIoS is a collaboration among Edwards, Fumin Zhang from the Georgia Institute of Technology and their two Georgia Tech Ph.D. students, Dongsik Chang and Sungjin Cho. GENIos has been tested for more than 210 glider-days on the continental shelf off Georgia and South Carolina. This experiment will be its first test in the Gulf of Mexico.

Edwards also hopes to use this project to test the gliders as platforms for new, experimental sensors developed by other members of the ECOGIG-2 team.

Others involved in ECOGIG-2 include UGA marine sciences faculty Christof Meile, Renato Castelao and Catherine Edwards as well as Annalisa Bracco and Joe Montoya of Georgia Tech.

For additional information, contact Catherine Edwards at (912) 598-2471 or catherine.edwards@skio.uga.edu.

Skidaway Institute scientists seek answers to salt marsh questions

January 2, 2013

Salt marshes are a vital part of the coastal ecosystem. They provide a nursery for many kinds of marine animal life. Sitting in the transition zone between the ocean and the land, salt marshes serve as a physical buffer against severe weather. They act as a chemical buffer by capturing, holding and releasing nutrients that are brought in on each tide. As a result, the marshes have a great influence on the type and amount of nutrients that enter the sounds and the ocean. That buffering capacity varies on tidal, daily and seasonal time scales, but how it functions is poorly documented.

A team of Skidaway Institute of Oceanography scientists have begun a project to get a clearer picture of how salt marshes function and interact with their surrounding environment.

The composition of the science team reflects the interdisciplinary nature of the project. Principal investigator Jay Brandes, Aron Stubbins and Bill Savidge are chemical oceanographers, and Catherine Edwards is a physical oceanographer. Geologist Clark Alexander and physical oceanographers Jack Blanton and Dana Savidge are also contributing to the effort. The three-year project is funded by a $699, 971 grant from the National Science Foundation.

The research team at Groves Creek (l-r) Clark Alexander, Jack Blanton, Catherine Edwards, Jay Brandes, Dana Savidge, Bill Savidge, Aron Stubbins

The research team at Groves Creek (l-r) Clark Alexander, Jack Blanton, Catherine Edwards, Jay Brandes, Dana Savidge, Bill Savidge, Aron Stubbins

“Scientists have looked at salt marshes in the past and have gotten some good data,” Brandes said. “However, this will be the first detailed look at the combined functions of one of these marsh systems.”

The project will focus on Groves Creek, a portion of coastal salt marsh along the Wilmington River, adjacent to the Skidaway Institute campus. Groves Creek has been the site of other research projects.  Over the past three years, Blanton, Alexander, Dana Savidge and others have studied the topography and water-flow in the marsh as part of a Department of Energy-funded project.  Because of this, the physical layout of the marsh has been documented to a fine detail.

“We already know a lot about this area, especially how the water moves in and out of the marsh on the tides,” said Brandes. “We have a very good understanding of the topography of the top of the marsh and its tidal creeks, both above and below the surface.”

The scientists also believe the Groves Creek area is fairly representative of salt marshes along the Georgia and South Carolina coasts.

From a chemical standpoint, the research will focus on way the salt marsh uses carbon: is it a consumer or producer of carbon-based organic material and nutrients?

“Marshes take material in from the river on every high tide, and they deliver material back to the river on the falling tide — but it isn’t the same stuff,” Savidge said. “The marsh changes the river chemistry on every tidal cycle.”

There isn’t much consensus on what controls that exchange between river and marsh. “That is one of the big questions,” said Brandes, “Trying to understand whether the marsh is a producer or consumer, and how that changes over time, the seasons, the tides and so on.”

To get a detailed history of marsh-river exchange, the scientists will place sensors in the marsh that will measure various conditions every 15 minutes. Remote sensors cannot measure everything, so the research team will also be collecting samples on a daily basis and returning them to their labs for analysis.  Understanding the big picture will come from adding up all the little incremental changes over time and relating them to the actions of sun, tide and weather on the marsh surface.

Stubbins will focus his efforts on the role of dissolved organic carbon in the marsh. Savidge will work look at how the salt marsh uses dissolved oxygen. Edwards will be modeling how water flows in and out of the system and how that movement interacts with the chemical and biological activity.

When the project is complete in three years, the Skidaway scientists expect to have a much more extensive picture of the role salt marshes play in the larger coastal ecosystem.

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Berger’s co-authors paper in Marine Biology

September 10, 2012

Stella Berger is one of the co-authors of a paper published recently in the journal, Marine Biology. The project studied the effect climate change has on the timing and magnitude of spring plankton blooms in both fresh- and saltwater ecosystems.

The entire paper can be accessed at: http://www.skio.usg.edu/aboutus/people/nejstgaard/downloads/Winder-Berger.pdf

 

A Day in the Life of a Citizen Scientist

June 21, 2012

Skidaway Institute volunteer scientist Nancy Tenenbaum recently travelled to Norway, to work with fellow Skidaway scientist Dr. Stella Berger. She described her experience in the form of a letter to her mentor, retired Savannah business leader and Skidaway Institute supporter,  Howard Morrison.       

Dear Howard,

Having had a few days to settle in here and wishing I could have packed you in my suitcase as well.  I am going to let you share the day with me through this letter.  I am in Espegrend, Norway, with a phytoplankton research project called Phytostress.  The word “stress” takes on a new meaning with this project. There are only a hand full of students and professors here to manage twelve mesocosms and three experiments.  In the course of the next two weeks I know I will need your encouragement and advise.

Rule #1 is “NEVER give up”. Howard Morrison

So, let the day begin.

7:00 AM

Taped to the window in my dorm room is a thick, black garbage bag to keep out the midnight sun.  Light at any hour after 10 pm is your worst enemy! Block it out at all costs. You might find it a bit challenging to navigate in my tiny dorm room. Most certainly it is not the spacious Civil War home, Lebanon Plantation, that you reside in. Through an open window in the kitchen field station birds sing incessantly. Fresh coffee waits patiently for the early riser made by Maria Segovia, the principal investigator of Phytostress. Norway has no version of half and half cream. Flotte,, heavy cream., is it. Putting a small amount in my coffee cup I think about the potential threat for artery clogging. Will I survive the day? On the wooden counter top a Norwegian breakfast of various cheese, lox, fruit muesli and a hardy multi-seed rye bread await.

View from the field station kitchen window.

 

Another view from the kitchen window

7:30 AM

You will need a jacket this morning as it is cool, about 11 degrees C (52 degrees F).  The fiord water sparkles in the sunlight.  On the hillside edelweiss, purple clover and yellow buttercups dance with the morning breeze. Compared to the weather when I was here in March, this is heaven.

Let me explain this project to you using an abstract provided by Maria Segovia, the principal investigator, for Phytostress:

Under the global change scenario around 40-50% of the CO2 emitted by anthropogenic activities is accumulated in the oceans causing acidification and increasing the availability of dissolved CO2 to primary producers (phytoplankton, algae, etc.). To understand the regulation of the carbon cycle it is basic to determine the interaction of the main factors controlling primary production in the ocean. The increase of UV radiation due to ozone loss can reduce the oceanic phytoplankton CO2 sinking capacity up to 2%. Concomitantly, the scarcity of micronutrients, such as iron, can affect the composition, functioning and growth of phytoplankton. However, although up to date there are several studies about the effect of UV on iron ocean speciation, there is none about the interaction between CO2, Fe (iron) and UV in phytoplankton, and the underlying mechanisms has not been elucidated yet. Equally, there is evidence of massive cell death phenomena in phytoplankton communities that can account for a great loss of biomass amount, altering diversity and hence affecting the carbon cycle. The proposed experiments, will lead us to a better understanding about the functions of marine phytoplankton as well as to determine how changes in CO2, UV and Fe availability control the fate of primary production in the ocean, regarding biomass and diversity loss.

In an introductory email before the research in May, Maria wrote that this mesocosm project is a dream come true for her.

8:45 AM

Howard, we are now at the dock.  I know how much you love to ride in boats.  Even though the ride to the raft will be quick it could be chilly. The swans that graced the fjord in March are gone.  Truthfully they were noisy, mean and not very white, like their counterparts in fairy tales.

Scientists and Ph.D. students, who are scheduled to sample water today, gather at the dock with sixteen, 25-liter carboys. Clothed in Healy Hansen immersion suits or only a life jacket they board small motorboats for the mesocosms.

You are now at the mesocosm raft.  Be careful on exiting the boat as the concrete raft moves with the current making its surface slippery. There are twelve covered mesocosms that are tethered to this raft.  A decoy hawk is mounted on a pole to scare off birds. It does absolutely no good! Birds actually seem attracted to it. Water is sampled by pumping H2O though a plastic meticulously washed tube into carboys. Full carboys of 25 liters are then loaded onto the boats, delivered to land and hauled up a hill using a flat wagon and human strength.

The mesocosm raft

THE MESOCOSMS

We are about to enter the lab when I spy a single wild yellow rose in full bloom. Immediately I am reminded of Antoine de Saint-Euprey’s story, The Little Prince. In this children’s book the rose is essential to the novel’s drama. Carefully tended by the prince, she is his motivation for leaving and returning to his planet. The rose in this book represents love, an invisible but essential emotion. If no passion exists to nourish life then the question presented is: can life survive? My passion extends to the invisible life of phytoplankton. They are in fact the unseen art forms. Simple, yet complex their balance in the food web is essential for life.

Howard, you often sign your emails with the quote: “Only those who can see the INVISIBLE can accomplish the IMPOSSIBLE!” Patrick Snow, Author, Creating Your Own Destiny

Armed with those words, I will take you into the lab hoping to have a productive day.

Actually the lab rooms are right out of Dr. Seuss!  Wacky and wonderful the equipment is dormant waiting for creative direction.  Machines hum and filtering systems wait expectantly. Life in the lab is a clandestine life unto itself.

We will need to double glove for this next task.  An elaborate washing protocol is the first order of duty.  Each sampling bottle must be washed with Deacon water, then immersed and soaked in HCl and finally rinsed five times with Milliq. H2O. As this involves a Fe (Iron) limitation experiment it becomes imperative to remove all possible traces of containment iron. This is a very time consuming process.

 

Ph.D students Charo, Armandoand and Candlera

The Espegrend Lab

10:30 AM

Dr. Stella Berger and I are on the microzooplankton team.  Microzooplankton can be defined as greater that 0.2-20 micrometers in size, which includes ciliates, dinoflagellates and diatoms. She is also working on a dilution experiment that she designed.

Dr. Stella Berger in command of the motorboat

Stella Berger with her dilution experiment

We return to the boat with Dr. Jose Fernandez from Malaga, to sample mesocosms numbers 1-6 and the fjord. Our samples are brought to our cold room. Part of every sample is then labeled and stored in covered boxes. Some are viewed as live slides in the inverted microscope. This is my favorite part of the day. Seeing the phytoplankton move and interact is just amazing. When I was here in March, I had the rare opportunity to meet and work with Andrei Sazchin. Dr. Sazchin is a Russian phytoplankton taxonomist.

Stella begins running her samples through a Flow Cam. Every cell is photographed and organized into libraries for later study. Each mesocosm sample involves a thirty-minute run process.

Flow Cam display of samples cell by cell

1:20 PM

I have a brief SKYPE conversation with my mentor and close friend, Sandra Nierzwicki-Bauer, Director of the Darrin Fresh Water Institute at Bolton Landing, Lake George, New York.

It does fact take a village of mentors to maintain the privilege of representing Skidaway Institute as a citizen scientist. Dr. Marc Frischer and Dr. Stella Berger are also instrumental in guiding me on scientific path.

2:30 PM

Lunch.  I am the only American here.  The Spanish lunch have a late, protracted lunch experience.  This long, heavy lunch is followed by lengthy scientific discussions in Spanish.

3:00 PM

Hope you are ready for a quick refreshing walk. The path by the fjord is a perfect place to reflect and regenerate. Bergen is a dichotomy. Look beneath the perfect postcard landscape and you will discover an ugly history of Nazi infiltration, which happened during WWII.

On the hillside adjoining the field station is the “castle.”  A Nazi once owned and lived in this forbidding residence. Inside, according to the locals, are memorabilia including swastikas that cover the walls.  Just looking upon it reminds me that six million Jews died as a result of Hitler.

Turning back to the water we are accosted by the smell of wild roses and rhododendron.  Seagulls cry. The sound of the water is soothing as it covers rocks and sand on a small beach.  Tiny islands with houses dot the fjord.  You can feel the ancient pulse of the land.  It emanates from the soil. Life despite its brief encounter with chaos and death has moved forward in a beautiful, peaceful way.

3:45 PM

Back in the lab we are ready to take the sample water for chlorophyll a (Chl a) is filtering in duplicate.  The lights are turned off and sunlight blocked by a makeshift shade as it excites the chlorophyll. A reading skewed by light will not be accurate. Once the water is filtered, the filter is put in a falcon tube, extracted with 90% acetone and then put in a covered box in a refrigerator where they stored for 6-24 hours.  The next day samples are measured by a fluorometer. This device measures parameters of fluorescence determining the amount of Chl a in the sample.

Filtering for chlorophyll a

 

Fluorometer

5:00 PM

We are back at a hood with an exhaust fan. After we have double gloved, each bottle will be immersed in hydrochloric acid for two hours.

6:00 PM

At some point every day it is good protocol update a lab notebook with general thoughts and data for the day.

7:00 PM

Stella has just finished running the last sample in the Flow Cam.  Slides from the inverted microscope used during the day are carefully washed.

7:30 PM

Dr. Jose’ Fernandez, Armando Olmo and I are on cooking duty tonight for 16 hungry people. You can pour the wine Howard to keep us happy while we cook. Tonight we will prepare paella. a traditional Spanish dish. This is a secret recipe of Jose’s grandmother.  I am chopping vegetables and hoping to learn the recipe for this famous meal. What I did manage to get from Jose’ is that the rice must absorb the flavors of the meat and vegetables. Timing apparently is everything.  So thanks to Jose the paella was delicious and a great success.

10:00 PM

The scientist and students sit down for dinner at a long narrow wooden table which seats at least 25. Most of the conversation is in Spanish.  Some students go back to the lab after dinner to finish up.

11:30 PM

Howard, there is something about the Norwegian blue hour that is pure magic.

The blue hour, not quite at sunset, floods the landscape with a purplish blue hue.  Maria’s two children are still running around with abundant energy. Laughing, and singing they are so undeterred by the hour.  I on the other hand am jet lagged and exhausted.  From my room I hear Maria’s husband calling his son Rodrigo to come inside.

Midnight sun

 

Sunset at the mesocosm raft. Photo by Maria Segovia.

Thanks for sharing the day with me!

Good night from the land of the midnight sun.

With love,

Nancy Tenenbaum –Citizen Scientist, Skidaway Institute of Oceanography

Notes from the Arctic – The end is near. August 30th, 2010

August 31, 2010

Hi All,

For a brief moment this morning the sun graced us with its presence and it was glorious.

Arctic summer splendor.

Today was our last day of sampling at our standard station and we made the best of it. Captain Quuniq and Nelson again took us out to our standard station and we quickly sampled and came back in to process our samples in the lab.

Sampling complete!

Compared to conditions yesterday afternoon, the ocean was a bathtub today. And, with all the kinks worked out of our equipment and protocols, we made record time processing the samples. Victoria was even able to complete our RNA purifications by dinner time.

Molecular biology on the go.

All the samples are now safely stored in liquid nitrogen and in shipping containers ready to be shipped out in the morning.

Shipping containers ready to go.

With all the sampling complete and after a quick and not very satisfying dinner of Ramen noodles, it was time to think about starting the process of cleaning and packing-up. Since our stuff is scattered all over the campus its quite a daunting task gathering everything, cleaning all of our salty equipment and packing it so that it will be organized and ready for next January.

Its nearly 2 am now and I’ve been at it since 7 so I think I have to cut this one short. Tomorrow promises to be a busy day of cleaning and packing, but the end is near and we’re all looking forward to heading home.

Marc