Posts Tagged ‘dnr’

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 scientists map Wassaw Sound

December 18, 2014

A research team from the University of Georgia Skidaway Institute of Oceanography has completed the first high-resolution, bathymetric (bottom-depth) survey of Wassaw Sound in Chatham County.

Led by Skidaway Institute scientist Clark Alexander, the team produced a detailed picture of the bottom of Wassaw Sound, the Wilmington River and other connected waterways. The yearlong project was developed in conjunction with the Georgia Department of Natural Resources.

This shows a wide view of the Wassaw Sound survey map. Shallow areas are shown in orange and yellow, deeper areas in green and blue.

This shows a wide view of the Wassaw Sound survey map. Shallow areas are shown in orange and yellow, deeper areas in green and blue.

The survey provides detailed information about the depth and character of the sound’s bottom. This information will be useful to boaters, but boating safety was not the primary aim of the project. The primary objective was to map bottom habitats for fisheries managers. DNR conducts fish surveys in Georgia sounds, but, according to Alexander, they have limited knowledge of what the bottom is like. “One of the products we developed is an extrapolated bottom character map,” Alexander said. “This describes what the bottom grain size is like throughout the sound. Is it coarse, or shelly or muddy? This is very important in terms of what kind of habitat there is for marine life.”

A second goal was to provide detailed bathymetric data to incorporate into computer models that predict storm surge flooding caused by hurricanes and other major storms. Agencies like the United States Army Corps of Engineers, the Federal Emergency Management Agency and the National Oceanographic and Atmospheric Administration use mathematical models to predict anticipated storm inundation and flooding for specific coastal areas. A key factor in an accurate modeling exercise is the bathymetry of the coastal waters.

“You need to know how the water will pile up, how it will be diverted and how it will be affected by the bottom morphology,” Alexander said. “Since we have a gently dipping coastal plain, storm inundation can reach far inland. It is important to get it as right as we can so the models will provide us with a better estimate of where storm inundation and flooding will occur.”

Funded by an $80,000 Coastal Incentive Grant from DNR, Alexander and his research team, consisting of Mike Robinson and Claudia Venherm, used a cutting-edge interferometric side-scan sonar system to collect bathymetry data. The sonar transmitter/receiver was attached to a pole and lowered into the water from Skidaway Institute’s 28-foot Research Vessel Jack Blanton. Unlike a conventional fishfinder, which uses a single pinger to measure depth under a boat, the Edgetech 4600 sonar array uses fan-shaped sonar beams to both determine water depth and bottom reflectivity, which identifies sediment type, rocky outcroppings and bedforms, in a swath across the boat’s direction of travel.

Skidaway Institute of Oceanography research coordinator Claudia Venherm logs survey activity on board the R/V Jack Blanton

Skidaway Institute of Oceanography research coordinator Claudia Venherm logs survey activity on board the R/V Jack Blanton

The actual process of surveying the sound involved long hours of slowly driving the boat back and forth on long parallel tracks. On each leg, the sonar produced a long, narrow strip indicating the depth and character of the sound bottom. Using high-resolution Global Positioning System data that pinpointed the boat’s exact location, the system assembled the digital strips of data into a complete picture of the survey area.

All the other sounds on the Georgia coast were mapped in 1933, but for some reason data from that time period for Wassaw Sound was unavailable. When the team began this project, they believed they were conducting the first survey of the sound. However, just as the researchers were finishing the project, NOAA released data from a 1994 single-beam survey that had been conducted in advance of the 1996 Olympic yachting races that were held in and near Wassaw Sound.

“This worked out very well for our project, because we are able to compare the differences between the two surveys conducted 20 years apart,” Alexander said. “We see areas that have accumulated sediment by more than 2 meters, and we also see areas that have eroded more than 2 meters since 1994. Channels have shifted and bars have grown or been destroyed.”

Because of advances in technology, the current survey is significantly richer in detail than the one conducted in 1994. “We can zoom down to a square 25 centimeters (less than a foot) on a side and know the bottom depth,” Alexander said.

The survey produced a number of findings that were surprising. The intersection of Turner Creek and the Wilmington River is a deep, busy waterway. Although most of the area is deep, the survey revealed several pinnacles sticking up 20 feet off the bottom. “They are round and somewhat flat, almost like underwater mesas,” Alexander said.

The researchers determined that the deepest place mapped in the study area was a very steep-sided hole, 23 meters deep, in the Half Moon River where it is joined by a smaller tidal creek. They also found several sunken barges and other vessels.

The survey data set is available to the public on the Georgia Coastal Hazards Portal at http://gchp.skio.usg.edu/. Alexander warns that while boaters should find the survey interesting, the information is intended for habitat research and storm surge modeling, not for navigation. “Because the bottom of Wassaw Sound is always shifting and changing, as our survey showed, don’t rely on the data for safe navigation,” he cautioned.

Alexander has already received a grant for an additional survey, this time of Ossabaw Sound, the next sound south of Wassaw Sound. He expects work to begin on that survey in early 2015.

The Skidaway Institute of Oceanography is a research unit of the University of Georgia located on Skidaway Island near Savannah. The mission of the institute is to provide the state of Georgia with a nationally and internationally recognized center of excellence in marine science through research and education.

UGA Skidaway Institute to study offshore sand resources to increase coastal resiliency

August 11, 2014

Severe beach erosion can be a significant problem for coastal communities affected by hurricanes and tropical storms like Hurricane Sandy. To assist Georgia communities in future recovery efforts, the University of Georgia Skidaway Institute of Oceanography entered into a cooperative agreement with the Bureau of Ocean Energy Management to evaluate existing data on Georgia’s offshore sand resources and identify where more data are needed. This consolidated information will increase knowledge of Georgia’s offshore sand resources and contribute to long-term coastal resilience planning.

“Georgia’s sand resources are arguably the least well-known of those along the East Coast, and this project will provide critical data and insights to enhance coastal resilience,” said UGA Skidaway Institute professor Clark Alexander. “The work is being coordinated closely with the Georgia Department of Natural Resources and the state geologist to assure that our findings are disseminated rapidly and broadly.”

Beach communities like Tybee Island  can be affected by hurricanes and tropical storms.

Beach communities like Tybee Island can be affected by hurricanes and tropical storms.

Under the $200,000 agreement, UGA Skidaway Institute will gather, evaluate and analyze existing geological, geophysical and benthic habitat data off Georgia’s coast and identify gaps in the information. Based on the data gaps, project scientists will suggest areas for future geologic studies to confirm previously identified sand resources and locate new ones.

“A reliable inventory of offshore sand resources will help the Department of Natural Resources be effective at representing the state’s interest in discussions with BOEM and other federal agencies. We appreciate the initiative of Dr. Alexander and the UGA Skidaway Institute and look forward to the results of this project,” explained Spud Woodward, director of the Georgia DNR Coastal Resources Division.

The current project will be limited in scope – primarily evaluating and consolidating existing data regarding Georgia’s offshore resources.

“Since the 1960s, there have been quite a number of small studies, but the information is scattered,” Alexander said. “This project contributes significantly toward the goal of more fully understanding available sand resources by synthesizing existing information into a single, digital resource.”

Much of the older information is only available in printed form, and needs to be converted to a digital format to be useful in the software that managers and scientists use for viewing and analyzing data. The goal of the project is to have all the compiled information readily accessible to coastal managers and municipal planners.

“This agreement demonstrates BOEM’s commitment to work with Georgia to help coastal communities recover from the effects of Hurricane Sandy and enhance resilience efforts for the future,” said BOEM Acting Director Walter Cruickshank. “We are committed to continuing to work in a collaborative manner to help local communities withstand damage from future storms.”

This agreement is one in a series of partnerships with 14 coastal Atlantic states, using part of the $13.6 million allocated to BOEM through the Disaster Relief Appropriations Act of 2013. The combined agreements support research that will help to identify sand and gravel resources appropriate for coastal protection and restoration along the entire Atlantic Outer Continental Shelf.

Skidaway Marine Science Day Schedule of Events

October 23, 2013

SKIDAWAY MARINE SCIENCE DAY

SATURDAY, OCTOBER 26, 2013 11AM-3 PM

CONTINUOUS ACTIVITIES (11AM-3 PM)

Jay Wolf Nature Trail, Interpretive Cabin, Learning Gardens (Open at 10 a.m.)

University of Georgia Aquarium Open – Free Admission

Behind the Scenes peeks at the UGA Aquarium. Every 20 minutes (11am-3pm) – pick up your ticket in the aquarium lobby and meet at the back door of the aquarium at your specified time! (Children under 18 must be accompanied by an adult. No strollers, please.)

Touch Tanks (Aquarium)

Touch Tanks (Aquarium Day Group Room)

Phytoplankton Lab Demo (Aquarium Plankton Lab)

Invertebrate Explorations: A Floating Dock Study (Aquarium Invertebrate Lab)

Crabbing on the Dock 12-3 p.m. (UGA Marine Extension Service Dock)

Environmental Group Exhibits (Skidaway Institute Quad)

Introduction to the online Georgia Coastal Hazards Portal (Skidaway Institute quad)

Studying ocean currents with radar (Skidaway Institute Quad)

Tours of Research Vessel Savannah (Skidaway Institute Dock)

Plankton World (McGowan Library overhang)

Build a Plankton (Tent outside the McGowan Library)

Plankton Sink-Off (Tent outside the McGowan Library) A Sink-Off round every 20 minutes

Science Exhibits (Skidaway Institute Quad & R/V Savannah)

Microbe Hunt – Grab a swab and find the microbes in the world around you. (Skidaway Institute Quad)

Gray’s Reef ROV Activity (Skidaway Institute Quad)

Oyster Reef Restoration Displays and Activities (Shellfish Lab Patio)

 SCHEDULED EVENTS

11:15am — Fish Feeding (Aquarium)

11:30am — Reptile Show with John “Crawfish” Crawford, Marine Educator (Screened porch)

11:45am – Fish Feeding (Aquarium)

12:15pm – Fish Feeding (Aquarium)

12:30 PM – “Bridges and Bulls: A history of Skidaway Island” A talk and walking tour by Dr. Bill Savidge (McGowan Library)

12:45pm – Fish Feeding (Aquarium)

1:15pm – Fish Feeding (Aquarium)

1:30pm – Reptile Show with John “Crawfish” Crawford, Marine Educator (Screened porch)

1:45pm – Fish Feeding (Aquarium)

Participating Environmental and Educational Groups

Georgia DNR-CRD

Gray’s Reef National Marine Sanctuary

The Dolphin Project

Savannah National Wildlife Refuge

Georgia Sea Turtle Center

Tybee Marine Science Center

Skidaway Island State Park

Georgia DNR – Law Enforcement

Savannah State University Marine Sciences Department

Armstrong Atlantic State University Diamondback Terrepin Project

Youth for a Cleaner Environment

LTER Research Project

Friends of the Wildlife Refuge

CCA

Hatchling sea turtle Rider to be on view at Skidaway Marine Science Day

October 21, 2013

Visitors to the Skidaway Marine Science Day will be able to catch a rare glimpse of Rider, the University of Georgia Aquarium’s new hatchling loggerhead sea turtle, on Oct. 26 from 11 a.m. to 3 p.m. Held on the north end of Skidaway Island, the free event will include behind-the-scenes tours of the aquarium, opportunities to explore research vessels and hands-on science activities. All activities at Skidaway Marine Science Day will be free of charge.

Rider the Loggerhead Sea Turtle

Rider the Loggerhead Sea Turtle

 The event is jointly presented by the UGA Aquarium and UGA Shellfish Laboratory, which are both part of Marine Extension, a public service and outreach unit of UGA, and by the UGA Skidaway Institute of Oceanography, Gray’s Reef National Marine Sanctuary and the Nature Conservancy.

 Only seven weeks old, Rider occupies a holding tank behind the scenes at the aquarium. Attendees can sign up at the aquarium welcome table for a tour of the space during Skidaway Marine Science Day. Only a limited number of openings will be available.

 Rider hatched on Aug. 29 in the Wassaw Island National Wildlife Refuge but never made it out of the nest to begin ocean life. Rider was discovered by Kris Williams of the Caretta Research Project, a long-term monitoring study of loggerhead reproduction and population trends that began in 1973. In collaboration with the U.S. Fish and Wildlife Service, Rider was rescued and transferred to the UGA Aquarium to help inspire and educate people about sea turtle conservation along the Georgia coast.

 Loggerheads are one of five sea turtle species that nest along the Georgia coast. While they are the most common, they are listed as threatened by the U.S. Fish and Wildlife Service and the Georgia Department of Natural Resources. Only one in 100 loggerheads survive to adulthood. DNR reports indicate that, after about 35 years of conservation efforts at the federal and state level, nesting numbers on the Georgia coast have been increasing dramatically over the last several years.

 Rider’s name refers to the early stage in the loggerhead life cycle, during which turtles off the eastern coast of the U.S. ride ocean currents far out in the Sargasso Sea and North Atlantic Gyre.  

 Ossabaw, Rider’s predecessor at the UGA Aquarium, is now two years old and currently on display in one of the main tanks. Loggerheads are kept at the UGA Aquarium for three to four years before being released into the wild or transferred to larger aquariums like the Georgia Aquarium in Atlanta.   

 Loggerhead sea turtles can reach sizes of approximately 48 inches in shell length and weigh up to 350 lbs. They reach sexual maturity between 20-30 years of age and nest on the Georgia coast generally during the months of April to September. Adult females can lay 50-120 golf-ball-sized eggs during a single nesting event, and egg temperature determines the gender of the offspring. Hatchlings feed on small invertebrates while juveniles and adults feed mainly on crabs and mollusks as well as sea jellies, salps and barnacles. 

Skidaway Institute scientist presents public program on coastal hazards

September 21, 2012

Coastal residents are exposed to a number of unique hazards associated with living near the ocean. These hazards range from hurricane storm surge to rapid erosion.  They occur both from natural processes and human activities.

Skidaway Institute of Oceanography professor Clark Alexander and Georgia Southern University professor Chester Jackson will present a program entitled “Living on the Edge – Coastal Hazards in Georgia” on Monday, October 22, at 7 p.m. in the Library Auditorium on the campus of the Skidaway Institute of Oceanography at the north end of Skidaway Island.

The talk is open to the public and admission is free.

The program is sponsored by the University of Georgia Marine Extension Service, the Skidaway Institute of Oceanography and the Georgia Department of Natural Resources.

If interested, please RSVP to (912) 598-2496.

Barrow — Jan 16

January 19, 2012

16 Jan 2012

Ice conditions are still unstable.  Our UMIAQ support team spent the morning doing reconnaissance of our intended sampling sites. After yesterday’s efforts they suggested that since it might be dangerous, it wasn’t a good idea for anyone on the science team to accompany them. Because the ice is still forming and the ocean is a powerful force, the ice can break-up pretty quickly. The team first scouted out our near shore site, but it was inaccessible due to a major crack between it and our ice trail. We use a trail cut through the ice to guide us on a safe snow machine run over it. They continued on to our second site located further out into the ocean and to the north. The ice in that area seems to be more stable. They liked what they saw and decided that it would be safe for us to set up camp there.

Brower Frantz, UMIAQ logistics leader proudly stands by the ice camp.

After making this decision the team came back, loaded up the camp gear (tents, generators, heaters, ice augers, etc) and went back out. This time Steven Baer from the Bronk group went with them to help orient the tents and make some basic measurements. Before starting we need to know the ice thickness, water depth, and usually how far light penetrates. In this case there basically isn’t any light but hey, we’re scientists. Measuring zero’s (or close to zero) can be just as important. Its data!

Meanwhile, back on the NARL campus where our labs are, there was a flurry of activity as we all checked and prepped our gear. Finally, around 3pm the camp was set-up and we were ready to go. I was pretty worried about how late it was getting, but because we have such a short time up here and the ice was deemed safe now we needed to push a little bit. Who knows if we’ll even get another chance given the dynamic condition of the ice.

The ride out was relatively uneventful. The ice was remarkably smooth compared to our previous trips.  As was explained to me, when the ice first forms it is relatively flat and it only gets jumbled up later as storms, wind, currents, and tides push it around. Flat ice generally means that it is new ice.  That is what was worrying everybody. We know the ice is still forming and moving a lot. Hopefully it won’t move while we’re on it! After about 30 min of driving we made it to our camp. Having well established sampling routines by now, this is our 6th expedition, we all got to work unloading our gear and starting to sample. The Yager group occupies their own tent (the smaller one) while the Frischer and Bronk group occupy the larger one.

Ice Camp 16 January 2012

In the Frischer tent I got started right away making measurements of the water column. We are using a new instrument that lets us measure depth, temperature, salinity, oxygen, chlorophyll, pH, and turbidity. It’s a pretty nice instrument but a bit delicate and the computer software is not straightforward. We transported it as if it was a delicate infant wrapped in blankets with warm water bottles and hand warmers to make sure it didn’t freeze on the way out. I think we overdid it! When I unwrapped it in the tent it was positively hot. The instrument worked well and we got a good look at the water conditions. As expected the water temperatures was -1.8 deg C, salinity was around 33 PSU (normal for the Arctic coastal ocean), there was almost no chlorophyll in the water (no light no algae in the water). Most importantly the water column was well mixed which means that we could sample at one depth and be reasonably assured that it would be representative of the whole water column. We decided to sample at 2 meters below the bottom of the ice.

Graph of water data from the MANTA, Eureka Environmental

After I was finished measuring the water the Bronk group got rolling. They rinse and fill what seem like a million small bottles to which they add a very small amount of nutrients enriched in their stable isotope concentrations. Stable isotopes are non-radioactive form of elements (atoms) that are slightly heavier than the normal form. For example, the normal atomic weight of Carbon is 12 (meaning it has 12 protons) while the stable isotopic form has a weight of 13. We refer to it as 13C.  Because 13C  is slightly heavier than 12C, it can be measured on a mass spectrometer. By measuring how much of it goes into cells during an incubation, the rate of uptake can be calculated. The Bronk group is making some of the first ever measurements of nutrient uptake rates by microbes in this region of the Arctic coastal ocean.

The process went pretty smoothly but since it was so cold, even in the tent, the pipettes which they were using to inject the stable isotope into the samples were freezing and slowing the process.

Dr. Debbie Bronk injects stable isotope labeled nutrients into seawater.

Meanwhile in the other tent the Yager group were having even more problems with freezing. They are collecting water samples to make measurements of the carbon chemistry and general activity of the microbes, so it is especially important that their samples do not freeze and are not exposed to the atmosphere which can contaminate the dissolved gas content of the seawater. Unfortunately, their samples were freezing.  However, after getting them off the ice floor of the tent and placing them into a seawater bath (a cooler filled with seawater) they seem to have solved the problem and were able to collect most of the samples they needed.

Dr Tish Yager and Colin Willams collecting water.

When the Bronk group was finished it was our turn.  Our sampling is probably the most straightforward, but we need to collect a lot of water.  We’re collecting enough water so that we can extract DNA and RNA from the bacteria in it.  We collect about 140 liters (about 40 gal or 310 lbs). Using a specially designed submersible pump we collected water in seven 20 liter carboys wrapped in neoprene and then place them in a cooler of snow. Believe it or not, the snow actually keeps the water from freezing. But, as simple as it sounds, we had our problems too. The generator that was running our pump ran out of gas.  Actually, the generator had a gas leak so it’s lucky it just ran out of gas and didn’t explode. But, because of excellent planning on the part of the UMIAQ team we had two generators on site. However, that meant the Yager group was without lights in their tent. We solved that problem by moving two snow machines so they pointed at the tent and the headlights provided enough light.

Finally we were all done and got all our gear and samples loaded back onto the sleds.  It was unbelievably cold and windy and we were all tired and ready to get back. The trip started off smoothly until I managed to get my sled stuck. It’s really tricky pulling a very heavily loaded sled. I had to slow down over a series of small ridges because the person in front of me slowed, and that was all it took for the snow machine to sink a little too much into some soft snow and lose traction. With all of us helping we disconnected the sled and managed to lift the back end of the snow machine out of snow, enough to get it moving. Then we were able to push the sled back to some more level ice and reconnect it to the snow machine. It was exhausting! But the fun wasn’t quite over. As we started moving again Debbie, in an effort to make it over the hole I had dug with the snow machine, went a little too fast over the area and bumped into Rachel and Jenna who were on the snow machine in front of them. No real harm though. Jenna fell off the snow machine but it was into soft snow and she wasn’t hurt. The brand new snow machine Deb was driving suffered a cosmetic crack in its fairing. Without further incident we all made it back safely to campus and quickly rushed our samples to our respective labs for processing.

Victoria and I spent the next 5 hours in our cold room filtering all that water we had collected. We had hoped to start another humic addition bioassay that is a component of Zac Tait’s thesis research, but it was just too late so we decided we’d do that first thing in the morning. After all the filtering was done, our samples put away safely, and all our gear cleaned-up it was time for some well deserved rest. I felt weary and frozen to the bone but pleased with the progress we had made.

Even though the sun won’t shine, tomorrow is a new day.

Erosion threatens Coastal Georgia archaeological sites

August 1, 2011

Along the Savannah River in Chatham County are the remains of a large, complex, former rice plantation. Archaeologists may be able to learn much about the life of Georgia’s early inhabitants by studying this site, but only if they hurry. Site 9CH685, as it is known, is threatened by shoreline and tidal creek erosion – the result of the nearby river moving closer to the site every day.

Site 9CH685 is just one of 42 archaeological sites on Georgia’s back barrier islands recently studied by a team from the Skidaway Institute of Oceanography and the Georgia Department of Natural Resources (DNR) Historic Preservation Division. The sites include a range of types, from Native American shell middens to colonial cemeteries and Civil War artillery batteries. The team spent two years studying the erosion and accretion patterns near each site to assist DNR in prioritizing the sites that require the most immediate attention. Funding for the project came from the Georgia Coastal Zone Management Program.

“The Georgia coast is constantly evolving,” said Clark Alexander, the Skidaway Institute scientist who directed the project. “During the past 150 years, the shoreline has moved more than a hundred meters along many parts of the Georgia coast.  The natural forces of wind and water have formed and changed the shape of our coastline over the centuries and continue to do so.”

Typically it is not feasible to preserve sites against these forces, so it is critical to document the sites before they are lost if there is any hope to record the history contained within them.

“Once an archaeological site has been eroded away, it cannot be replaced and the information it contained is lost forever, said Chris McCabe,  deputy state archaeologist for the Georgia Department of Natural Resources (DNR). “The loss of archaeological information to natural processes in our dynamic coastal setting is an ongoing issue for us.”

The team used a combination of current shoreline measurements near the known sites, combined with historical shoreline information from aerial photographs, charts and maps, some dating back to the mid-19th century.

Skidaway Institute's Claudia Venhern uses a highly accurate GPS instrument to record the shoreline of a Georgia coastal island.

It was Skidaway Institute researcher Claudia Venherm’s job to survey the current shoreline. Using an extremely precise GPS receiver, she walked the shorelines measuring the exact location of the high water mark within a few inches. Later, she mapped the shoreline and compared it with the historic data for the same location to determine how fast the shoreline is changing.

“We can use Geographic Information System (GIS) technology to overlay the location of the current shoreline with the shorelines from older photos and maps and obtain a very good picture of what is happening to any piece of coast,” Venherm said.

All the sites were examined to determine which were in the most danger of loss to erosion. The projected life of each site was calculated as the number of years until erosion would destroy the entire site.

Six sites had already been lost to erosion by the time the team visited the coordinates for these sites. Four more sites were still present, but are completely or almost completely submerged at all stages of the tide. The team determined 21 of the sites were eroding, and three of those have a projected life of less than 50 years.

“This study will be a big help to us,” said McCabe. “We can’t stop the erosion, but we can prioritize our work, and maximize the amount of cultural information we obtain before a site is lost.”

That rice plantation site has already yielded clues about the early Georgia economy. The tidal creek threatening the main site has produced several surface artifacts from the late 19th and early 20th centuries. A section of whiteware dinner plate etched with the name “Greenwood China Company”, which designed dinnerware specifically for use aboard coastal steamboats, was found in the creek bed.

“This artifact suggests that materials from maritime vessels had found their way to a group of individuals living at the plantation,” said McCabe. “In addition, an aqua colored bottle embossed with the name ‘Packard & James New York’ was found.”

This merchant firm distributed spices and coffee at the end of the 19th century, and its discovery at a Savannah River site hints at important turn-of-the-century maritime sail and steam trading networks.

These glimpses into the past are fleeting however, as time and tide erase these ephemeral fragments of history.  This study provides the data that the DNR needs to save as much of Georgia’s rich coastal history as possible.

Skidaway Institute introduces new coastal management tools

November 23, 2010

Scientists from the Skidaway Institute of Oceanography have introduced a powerful new tool to monitor coastal erosion to coastal planners and managers.

The digital tool, AMBUR (Analyzing Moving Boundaries Using R), was developed to analyze shoreline change along barrier islands with complex shapes and highly curved shorelines.

“One of the issues in dealing with a constantly changing coastline, like ours here in Georgia, is just getting a good picture of the changes over time,” said Clark Alexander, a Skidaway Institute scientist. “AMBUR was developed to do just that.”

An analyst using AMBUR can take data from maps, aerial photographs or raw GPS data and use it to compute erosion and accretion rates in complex situations.

AMBUR was developed by Chester Jackson as his doctoral project at the University of Georgia. Jackson is currently on the faculty of Georgia Southern University and is a partner in this series of workshops. David Bush of the University of West Georgia is also working with Alexander and Jackson.

The three scientists introduced AMBUR to Georgia coastal managers and planners in a workshop in mid-November. Attendance included 8 GIS professionals representing Camden, Glynn, Chatham and McIntosh Counties, the City of Kingsland, the Sapelo Island National Estuarine Research Reserve and the Coastal Regional Council.

Workshop participants learn the art of beach profiling on Tybee Island beach.

Two additional workshops were held to present the program to non-governmental groups who are interested in monitoring shoreline changes. The two programs were held on Tybee Island and Jekyll Island, and attracted 16 interested observers representing Friends of Sapelo, the Jekyll 4-H Center, the King and Prince Hotel, the Sapelo Island National Estuarine Research Reserve, the Tybee Island Beach Task force, the City of Tybee and the Burton 4-H Center

The AMBUR project is funded by a Coastal Hazards grant from the Georgia Sea Grant Program. Georgia’s Department of Natural Resources, Coastal Resources Division also partnered on the project.

Nice newspaper article

November 24, 2009

Mike Sullivan writes:

Several of us spent most of last Friday taking a boat trip to one of Georgia’s undeveloped coastal islands

Capt. Jay Fripp and Claudia Venherm

and stomping around looking for archaeological sites that may be threatened by erosion.

Claudia Venherm using a precise GPS to map the shoreline.

It is a joint project with Chris McCabe, the Georgia DNR archaeologist who is stationed on our campus.

Chris and Mary

Mary Landers from the Savannah Morning News came along and wrote a very nice story on the excursion, which can be seen here.