Archive for the ‘Algae’ Category

UGA Skidaway Institute scientists study microbial chemical warfare

April 18, 2017

In the battlefield of the microbial ocean, scientists have known for some time that certain bacteria can exude chemicals that kill single-cell marine plants, known as phytoplankton. However, the identification of these chemical compounds and the reason why bacteria are producing these lethal compounds has been challenging.

Now, University of Georgia Skidaway Institute of Oceanography scientist Elizabeth Harvey is leading a team of researchers that has received a $904,200 grant from the National Science Foundation to fund a three-year study into the mechanisms that drive bacteria-phytoplankton dynamics.

Researcher Elizabeth Harvey examines a part of her phytoplankton collection.

Understanding these dynamics is important, as phytoplankton are essential contributors to all marine life. Phytoplankton form the base of the marine food chain, and, as plants, produce approximately half of the world’s oxygen.

“Bacteria that interact with phytoplankton and cause their mortality could potentially play a large role in influencing the abundance and distribution of phytoplankton in the world ocean,” Harvey said. “We are interested in understanding this process so we can better predict fisheries health and the general health of the ocean.”

This project is a continuation of research conducted by Harvey and co-team leader Kristen Whalen of Haverford College when they were post-doctoral fellows at Woods Hole Oceanographic Institution. They wanted to understand how one particular bacteria species impacted phytoplankton.

A microscopic view of a population of phytoplankton

“We added the bacteria to the phytoplankton and the phytoplankton died,” Harvey said. “So we became very interested in finding the mechanism that caused that mortality.”

They identified a particular compound, 2-heptyl-4-quinlone or HHQ, that was killing the phytoplankton. HHQ is well known in the medical field where it is associated with a bacterium that can cause lung infections, but it had not been seen before in the ocean. The team will conduct laboratory experiments to determine the environmental factors driving HHQ production in marine bacteria; establish a mechanism of how the chemical kills phytoplankton; and use field-based experiments to understand how HHQ influences the population dynamics of bacteria and phytoplankton.

“This project has the potential to significantly change our understanding of how bacteria and phytoplankton chemically communicate in the ocean.” Harvey said.
The project will also include a strong education component. The researchers will recruit undergraduate students, with an effort to target recruitment of traditionally under-represented groups, to participate in an intense summer learning experience with research, field-based exercises and some classroom work.

“The idea is for the students to return to their home institutions at the end of the summer, but to continue to work with us on this project,” Harvey said. “This will be a unique opportunity to offer students cross disciplinary training in ecology, chemistry, microbiology, physiology and oceanography.”

In addition to Harvey and Whalen, the research team includes David Rowley of the University of Rhode Island.

NOTE:  A complementary video with an interview with Dr. Harvey is available at http://www.skio.uga.edu/news/videos/

 

Tiny but all-consuming marine organism focus of UGA Skidaway Institute study

February 8, 2017
Marc Frischer

Marc Frischer

Doliolids are tiny marine animals rarely seen by humans outside a research setting, yet they are key players in the marine ecosystem, particularly in the ocean’s highly productive tropical and subtropical continental margins, such as Georgia’s continental shelf. University of Georgia Skidaway Institute of Oceanography scientist Marc Frischer is leading a team of researchers investigating doliolids’ role as a predator in the marine food web.

Doliolids are small, barrel-shaped gelatinous organisms that can grow as large as ten millimeters, or about four tenths of an inch. They are not always present in large numbers, but when they bloom they can restructure the marine food web, consuming virtually all the algae and much of the smaller zooplankton.

A doliolid with a cluster of juvenile doliolids on its tail. Actual size is approximately three millimeters, or one eighth inch.

A doliolid with a cluster of juvenile doliolids on its tail. Actual size is approximately three millimeters, or one eighth inch.

“The goal of this particular study is to find out what the doliolids are eating quantitatively,” Frischer said. “This is so we can understand where they fit in the food web.”

Scientists know from laboratory experiments what doliolids are capable of eating, but they don’t know what they actually do eat in the wild. They are capable of eating organisms as small as bacteria all the way up to much larger organisms.

“What they are eating and how much are they eating from the smorgasbord that is available to them, that is the question,” Frischer said. “We are investigating how much of those different prey types they are really eating out there across the seasons.”

The project involves intensive field work, including 54 days of ship time on board UGA Skidaway Institute’s Research Vessel Savannah. During the cruises they conduct trawls using special plankton nets to collect the doliolids. They also collect water samples to understand the conditions where the doliolids thrive.

Graduate students Lauren Lamboley and Nick Castellane deploy a plankton net from the Research Vessel Savannah.

Graduate students Lauren Lamboley and Nick Castellane deploy a plankton net from the Research Vessel Savannah.

“We take the doliolids and the water samples back to the laboratory, and that is where the magic begins,” Tina Walters, Frischer’s laboratory manager said.

Because the animals are gelatinous and very delicate, the researchers cannot use classical microscopic techniques to dissect the animals and analyze their gut content. Instead they extract DNA from the animals’ gut and use sequence-based information to determine what the doliolid ate.

“We go through a process called quantitative PCR,” Walters said. “So even though we can’t see the prey in a doliolid’s gut, because the prey have unique DNA sequences, we can identify and quantify them using a molecular approach.”

The three-year project is funded by a $725,000 grant from the National Science Foundation and will run until February 2018. Frischer’s collaborator on the project is Deidre Gibson from Hampton University. Gibson received her Ph.D. from the University of Georgia in 2000, and did much of her graduate research at Skidaway Institute with Professor Gustav Paffenhöfer.  In addition to Walters, Savannah State University graduate student Lauren Lamboley is part of the team, along with a number of students at Hampton University. Several undergraduate research interns have also participated in the project, gaining hands-on research experience. Frischer is also working with the Institute for Interdisciplinary STEM Education at Georgia Southern University to engage K-12 teachers by inviting them to participate in the research cruises.

UGA Skidaway Institute develops cutting-edge microbial imaging laboratory

December 7, 2016

A team of researchers from the University of Georgia Skidaway Institute of Oceanography has received a $226,557 grant from the National Science Foundation to acquire state-of-the-art imaging equipment to investigate microorganisms from the tiniest viruses to larger zooplankton. The equipment will be housed in UGA Skidaway Institute’s new Laboratory for Imaging Microbial Ecology, or LIME.

Researcher Elizabeth Harvey leads the research team that also includes UGA Skidaway Institute scientists Julia Diaz, Marc Frischer, James Nelson and James Sanders.

The equipment will improve Skidaway Institute’s capability to conduct field and laboratory experiments by automating many viewing methods.

“Anyone who uses a microscope will tell you that it is both tedious and time consuming,” Harvey said. “This equipment will allow us to enumerate and analyze microbes and other planktonic organisms much faster, and will allow us to do more large-scale projects than we could in the past.”

UGA Skidaway Institute researchers Tina Walters, Marc Frischer and Karrie Bulski practice running zooplankton samples on the FlowCam, a new instrument that is part of LIME.

UGA Skidaway Institute researchers Tina Walters, Marc Frischer and Karrie Bulski practice running zooplankton samples on the FlowCam, a new instrument that is part of LIME.

Much of the equipment will also have imaging capability so researchers will be able to do more detailed measurements on the size and shape of the tiny organisms and how that might relate to the health of an ecosystem.

Marine microbes are an essential component of all marine ecosystems and they play central roles in mediating biogeochemical cycling and food web structure.

“They are the things that drive all other processes in the ocean,” Harvey said. “They play a really important role in the way nutrients, oxygen and carbon are cycled through the ocean. We care a lot about those processes because they impact our climate, fisheries and the ocean’s overall health.”

A sampling of phytoplankton   imaged by the LIME's FlowCam.

A sampling of phytoplankton imaged by the LIME’s FlowCam.

The benefits of LIME will be shared beyond Skidaway Institute’s science team. Harvey envisions it as a regional center for microbial imaging, available to any other researchers who need the capability.

“Anyone is welcome to come here and get trained to use them,” she said. “They just need to contact me and we can make arrangements.”

Some of the equipment is already in place, while other pieces have not been delivered. Harvey anticipates all the equipment being functional by mid-2017.

UGA Skidaway Institute team studies nutrient levels in Georgia’s coastal estuaries

June 6, 2016

How much of a nutrient load is too much for Georgia’s coastal rivers and estuaries? A research team from University of Georgia Skidaway Institute of Oceanography is helping Georgia’s Environmental Protection Division answer that question. Their primary focus is on the estuary at the mouth of the Ogeechee River, where the researchers are measuring nutrient concentrations and other water properties to determine how they change as they flow through the estuary.

The nutrients are chemicals like nitrates and phosphates typically introduced into the rivers by agricultural runoff, storm water or sewage effluents, and the natural decay of organic matter in the river. When present in high concentrations, the nutrients act as fertilizer, promoting excessive growth of marine plants, especially microscopic marine plants called phytoplankton.

Researcher Kate Doyle lowers a sensor package into the water to measure salinity, temperature and depth.

Researcher Kate Doyle lowers a sensor package into the water to measure salinity, temperature and depth.

Elsewhere on the East Coast, excessive nutrients in estuaries have been linked to toxic algal blooms that can cause fish kills or shellfish closures. Death and decay of algal blooms by bacteria can drive oxygen concentrations down to levels that are unhealthy for other marine life. These are not presently known to be significant problems in Georgia’s waters, but scientists and regulators do not know what the thresholds are for developing water quality problems.

“The Georgia EPD wants to know how much nitrogen is coming down the river and whether it has any consequences when it gets to the estuary,” said UGA Skidaway Institute scientist William Savidge. “It doesn’t really matter if you have high nutrient concentrations if it is not having a harmful effect.”

The EPD is interested in these issues because they are mandated by the Environmental Protection Agency to set limits on nutrient levels for Georgia’s estuaries. Savidge describes the mandate as a difficult problem for several reasons.

“There is not any current and systematic information on nutrient conditions in most of the estuaries,” he said, “nor is there much information on the consequences of nutrient availability in the estuaries, and it’s those consequences that are the most important.”

They are currently mapping the biological and chemical properties of the Ogeechee River estuary each season to assess the nutrient changes throughout the year and to see what effects can be seen in the river and the estuary. Twice every quarter for the last year, the researchers have followed the incoming tide and sampled the river continuously as they moved upstream from the mouth of the estuary to fresh water. They used an onboard set of sensors to obtain continuous surface measurements of temperature, salinity, dissolved oxygen, chlorophyll (indicative of phytoplankton), turbidity and colored dissolved organic matter. In addition to the continuous surface measurements, the team stopped periodically and collected water samples from the bottom and throughout the water column. The product of each of these expeditions was a detailed map of conditions on the river, and when and where they are changing.

Researcher Lixin Zhu filters larger-volume surface water samples collected from the flow-through system to analyze for dissolved organic carbon.

Researcher Lixin Zhu filters larger-volume surface water samples collected from the flow-through system to analyze for dissolved organic carbon.

As they expected, Savidge and his team observed a wide range of conditions depending on the season. Nutrient inputs tend to be highest in the spring when agricultural fields are fertilized.

“Nutrient delivery is high in the spring, but we don’t have a high chlorophyll concentration in the Ogeechee River because, presumably, the nutrients are being washed off into the coastal ocean before any effect is noticed,” Savidge said

On the other hand, chlorophyll levels — which indicate phytoplankton population — are highest in the summer. Low summer river flow means water remains in the system longer. When combined with more sunlight and warmer temperatures, this slow flow this allows more time for the microscopic plants to grow.

In addition to sampling the Ogeechee River, the team is also conducting a smaller sampling project in the Altamaha River for comparison purposes.

Field work on the project will end in June, and Savidge expects to report the team’s findings to Georgia EPD by mid-summer.

“The Georgia EPD is going to have to balance the potential negative risks of nutrient loading versus the economic consequences of restricting nutrient additions,” Savidge said. “If, for example, most of the nutrient additions are agricultural, and that is creating problems downstream, the Georgia EPD may be forced by EPA to regulate nutrient additions, either by restricting how much fertilizer is placed on fields or mandating larger buffer zones around rivers and creeks.”

In addition to Savidge, the research team includes UGA Skidaway Institute scientists Jay Brandes and Aron Stubbins, research associate Kate Doyle and graduate student Lixin Zhu. UGA researchers Brock Woodson and Mandy Joye are also contributing.

26 Hours on the Marsh — November edition

November 6, 2014

Associate Professor Aron Stubbins led a 26 hour sampling program on the marsh. The team, including Thais Bittar, Robert Spencer, Zachary Tait, Megan Thompson, Alison Buchan, and Drew Steen, spent the day and night monitoring a day in the life of the microbes, gases and organic carbon molecules that form the biogeochemical milieu of the marsh. This work is part of two National Science Foundation projects involving professors and students from Skidaway Institute of Oceanography, University of Tennessee – Knoxville, and Florida State University.

Cutting edge techniques are being employed to watch the marsh creek in real time over 18 months. The sampling event shown in the time lapse video is the fall rendition of four seasonal sampling events that are recording the daily life of the creek. Manual sampling is required so that we can collect live bacteria and gas (such as carbon dioxide) samples that need to be processed by hand, immediately upon collection. The bacteria collected are being genetically characterized, so we know who was in the creek at different times of day (DNA). Then we will also determine which genes were active (RNA). This tells us what the bacteria present in the marsh were doing throughout the day.

We also record the changes in dissolved organic carbon throughout the day. Dissolved organic carbon is a major part of the global carbon cycle and so understanding its cycling is important with respect to understanding how natural carbon cycling responds to and plays a role in climate change. For the microbes in the creek, the dissolved organic carbon (DOC) is food. So by looking at which bacteria are there (DNA), what they are doing (RNA), and what types of food is present (DOC), we hope to gain a more complete understanding of the miniature world within every drop of creek water. The daily routines of these tiny bacteria and dissolved organic molecules shape the marsh ecosystem and play important roles in determining the current and future climate of our planet.

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

Skidaway scientist working on international research team

June 8, 2012

Skidaway Institute scientist Stella Berger is spending time in Norway, as part of an interesting project involving an international team of researchers. They are looking at the relationship among carbon dioxide, iron and ultra violet radiation as they relate to the production of phytoplankton in the ocean.  You can read more about it at the team’s blog http://phytostress.wordpress.com/.

Global warming may mean big changes to marine ecosystems

July 20, 2011

As the Earth’s climate continues to warm, what kind of effects will we see in the ocean and the world in general? Seeking the answer to that broad question is one of the reasons scientists from the Skidaway Institute of Oceanography are working with an international team of scientists on an experiment in Bergen, Norway.

“There is really no doubt that our planet is changing,” said Skidaway Institute scientist Marc Frischer. “Levels of carbon dioxide are increasing, and we are seeing changes in climate. There is very little controversy about that anymore.”

According to Frischer, scientists need to investigate what those changes will mean to life in the ocean — from the tiniest bacteria up to fish and larger organisms.

“Those are the kinds of questions that are important to us humans, because we are dependent on the life in the oceans for our existence here on Earth,” added fellow Skidaway Institute scientist Jens Nejstgaard.

Frischer, Nejstgaard, Skidaway Institute research coordinator Stella Berger, and graduate student Zachary Tait are part of a team of 37 scientists who have come together from 13 countries to join their individual expertise in an effort to solve some of these very complicated questions.

Skidaway Institute mesocosm research team (l-r) Zac Tait, Jens Nejstgaard, Marc Frischer and Stella Berger

“What’s happening with climate warming is not only are we increasing temperature, we are also increasing the carbon dioxide (CO2)which has the effect of acidifying the ocean – just like a can of cola,” said Frischer. “In this experiment we are studying not just temperature or acidity individually, but their combined synergistic effects”.

What makes it so complicated to study is that there are many different organisms interacting with each other, and at the same time reacting differently to the climate change.

“So instead of just picking out a few organisms to look at in the laboratory, we have to investigate large representative pieces of the ecosystems to tell what effect the climate changes will have on the environment,” said Nejstgaard.

The experiment was conducted at a mesocosm facility of the University of Bergen. There, the scientists could enclose two and a half cubic meters of natural seawater in each of 14 tanks, recreating an ecosystem with all the biological and chemical components that exist in the natural water column. They are called mesocosms because they represent intermediate systems that are bigger than a laboratory test tube but smaller than the ocean. The researchers changed the temperature and CO2concentrations in the mesocosms, and then observed how the various parts of the ecosystem reacted.

The Bergen mesocosm facility

“Mesocosms provide the opportunity to conduct controlled experiments that are impossible to do either directly in the ocean or in the laboratory,” said Nejstgaard.

The team also added a third factor to the experiment. Gelatinous organisms are an important part of the oceanic ecosystem, but typically they are fragile and do not survive the process of pumping seawater into the mesocosm tanks. In order to more closely mimic the natural marine environment, the researchers added tiny gelatinous organisms called appendicularians as representative “jellyfish” to the tanks after they were filled.

The Bergen mesocosm facility is the longest continuously operating mesocosm facility in the world. It has run for 33 years and Nejstgaard has led international experiments there for the two last decades.

Since 2009, Nejstgaard has directed the first European coordination of mesocosm facilities, MESOAQUA (http://mesoaqua.eu/), together with Berger as a scientific coordinator. Although Nejstgaard relinquished his position in Bergen in order to join the faculty of the Skidaway Institute of Oceanography in January 2011, Berger maintains a part time position in the MESOAQUA program. Frischer and other Skidaway Institute scientists have been collaborating with the Bergen facility for more than a decade. This was their fifth experiment there.

The funding for this experiment was complicated. Both American and European scientists applied for research grants. The Europeans got their funding; the Americans did not. The funding came from the Norwegian Research Council, the Nordic Council of Ministers (NordForsk) and MESOAQUA. Luckily two of the three European grants provided some travel support for non-Europeans, making it possible for the Skidaway team to participate.

Although the team was international, the original design for the project came from a small group including Frischer, Nejstgaard and Norwegian colleagues. Their primary focus was on the effect ongoing changes would have on oceanic bacteria. Very preliminary results look good for bacteria, but not so much for the rest of the marine ecosystem.

“Our preliminary data suggests that rising acidity increases bacterial activity, which has some profound implications on how the ocean is going to change,” Frischer said. “If conditions favor the growth of more bacteria, they will benefit at the expense of other types of microscopic marine life, particularly marine algae like phytoplankton.”

Phytoplankton are a major part of the bottom of the food web. Their productivity has a direct effect on the food supply for microscopic animals (zooplankton) and all larger marine animals. On the other hand, energy that goes into the bacteria is believed to just cycle among very small organisms that are hard for the larger organisms to eat. If that is so, the global warming spell even more problems for the ocean’s already troubled fisheries.

“When you start looking at how all the little pieces are connected, those insights we gain will help us understand how our planet will change and what that will mean,” Frischer concluded. “That is what we are trying to learn and it is important to every aspect of our society.”

Since it is important to investigate the effect of environmental changes on different natural communities, the Skidaway Institute team hopes to be able to obtain funding to continue experiments in Bergen, and elsewhere, including in our own backyard.

“We hope to develop a world-class mesocosm research center at the Skidaway Institute of Oceanography where we believe the potential exists for the Institute to become a leading facility for the region,” said Nejstgaard. “Such a center would contribute to future studies of the many environmental challenges that face our region.”

Skidaway Institute scientists use microscopic algae to track coastal water quality

January 12, 2009

As burgeoning growth on the Georgia Coast puts additional pressure on the fragile coastal environment, scientists at the Skidaway Institute of Oceanography are researching new techniques to monitor coastal water quality.liz-mann-lab-1

Scientists can measure water quality several ways. One method is to measure the water’s chemical characteristics, such as oxygen and nutrient concentrations. Skidaway Institute researcher Elizabeth Mann is investigating another technique – using a group of microscopic organisms as a bioindicator of water quality.

“When you measure the chemical composition of the water, you essentially get a snap shot of all the individual components in the water at the time you take your sample,” Mann said. “We are trying to determine if the micro-organisms in the water will give us a better picture of water quality because living cells must adapt to all of the stresses in an environment over a longer time span.”

Mann’s research focuses on one of the smallest of microscopic algae or phytoplankton called cyanobacteria. These organisms are less than 2 microns in size and form the base of the food web. Like plants, cyanobacteria such as Synechococcus contain chlorophyll and manufacture their own food through photosynthesis.

Cyanobacteria have many characteristics that make them potentially good indicators of water quality. Synechococcus are abundant in Georgia’s coastal waters and are relatively easily isolated and grown in the laboratory. They can also be identified and counted using flow cytometry, a technique that can accurately count up to 500 cells a second.

“Cyanobacteria can serve like a canary in a coal mine,” said Mann. “Changes in Synechococcus populations may help monitor the condition of the environment in which they live because these small phytoplankton are more sensitive to toxic metals such as copper and cadmium than larger marine algae.”

Mann is examining the water quality in the Savannah River by comparing conditions in that heavily industrialized estuary to the more pristine Altamaha River.

The abundance of cyanobacteria, including Synechococcus, is much lower in the Savannah River than in the relatively pristine Altamaha,” Mann said. “Not only is the total number of cyanobacteria lower in the Savannah River, but certain types of microbes abundant in the Altamaha River are essentially absent from the more heavily impacted Savannah River.

In addition, Mann said, adding water from the Savannah River to populations of estuarine phytoplankton from more pristine locations leads to a decrease in the abundance of cyanobacteria and other small phytoplankton.

Mann’s work is just beginning. A next step will be to identify the types of contaminants responsible for low Synechococcus numbers in the Savannah River and to determine what effect stunted cyanobacteria populations have on the larger organisms in the food web that prey on these small plants.

Hot summer internships

July 24, 2008

We have a group of five interns from Clark-Atlanta University and Spelman College just finishing up a two-month internship with Dick Lee’s aquaculture project.

Here you can see research tech Karrie Brinkley (3 from right) working with (l-r) Diamond Carr (Clark Atlanta), Matilda Young (Clark Atlanta), Chanelle West (Spelman) , Jolill Ross (Spelman) and Ashley Shannon (Clark Atlanta.)

Apparently the hot summer on a Georgia coastal island was quite a suprise to several of them. I think a couple of the chemistry majors thought they would be spending the internship in a lab coat in an air conditioned building. Actually, they did a lot of work outside in our raceways (ponds) and greenhouses.

Two of the students worked on a project to grow edible seaweed as a secondary crop. The wastewater on the salt water side of the system contains plenty of nutrients. Above, see Chanelle West harvesting some.

Here (you can see everyone, except for Ashley Shannon, who is picking a pepper (below) at this moment. (l-r) Channelle West, Matilda Young, Jolill Ross and Diamond Carr.

The will finish up by presenting as seminar to the campus community next Wedndsday at 10 am. Chanelle and Diamond will report on their seaweed project. Matilda will present a business plan for some future aquaculturist who may want to start a commercial operation. Jolill and Ashley will report on their effort to obtain ethanol from the pond scum that floats on top of the outdoor raceways and the algae that is suspended in the water.