UGA Skidaway Institute drones monitor Tybee Island dunes

In recent years, some coastal communities have begun building man-made sand dunes as an alternative to hard structures like sea walls to protect their beaches from natural erosion and the effects of storm surges. Now researchers at the University of Georgia Skidaway Institute of Oceanography are studying the man-made dunes on one Georgia island to determine if man-made dunes really are the best answer to the beach erosion problem.

Tybee Island dunes

Every five to seven years for the past few decades, the Army Corps of Engineers has pumped thousands of tons of sand onto the beaches of Tybee Island to renourish the beaches that became reduced by natural erosion and the influence of the Savannah River ship channel. In the last renourishment, completed in early 2020, the Corps included some additional sand. The City of Tybee Island used the sand to form dunes to supplement the existing dune system. What is not known is whether this is a good long-term solution compared with other remedies like sea walls and rock revetments.

“We know sand dunes are protective, and that building dunes is better and cheaper than building seawalls,” UGA Skidaway Institute researcher Clark Alexander said. “The goal of our project is to determine how they function after you build them, and how they change so we can better manage them in the future.”

Alexander and his team are using drones and high-tech mapping technology to monitor the dunes to see how well the dunes effectively stand up to the forces of nature.

A drone in flight

“We want to monitor the dunes and let Tybee know how they are changing, where they are changing most rapidly and where they might want to concentrate future deposits of sand,” Alexander said.

It takes four to five days for the drone to survey all the Tybee beaches. During each flight, the drone will take thousands of overlapping pictures. The drone team begins by placing markers on the ground. They pinpoint the markers’ positions and elevations using a global positioning system that is accurate to within a couple of centimeters (less than an inch). Using these markers as known reference points, geographical information software analyzes the drone pictures and creates a three-dimensional model of the beach and dunes. By comparing the results of the surveys over time, Skidaway researchers monitor the changes in the dune system.

Volunteer Kate Burns “catches” a drone as it returns from a flight.

Like many barrier islands, Tybee’s beaches do not erode uniformly from one part of the island to another. This project will help the city to better predict what sections are going to need attention before others. Alexander points to the center of the island which has multiple rows of dunes and actually developed additional dunes naturally with each renourishment project. On the other hand, the north and south ends of the island are subject to a greater rate of erosion and some sections had no dunes at all until the man-made dunes were built there.

Research technician Claudia Venherm flies a drone while volunteer Cathy Lewis looks on.

The results of this project will be felt far beyond the shores of Tybee Island. Alexander and his team plan to produce a “best practices” manual that can be used by other coastal communities. “So that other communities, if they do decide to build dunes, they will have a starting point for how to monitor them,”
Alexander said. “This may be applicable to Jekyll Island that is trying to figure out how to protect their upland while their beaches are eroding. And St. Simons Island has sections of their island that are at risk.”

Alexander said beach renourishment was the first step to move away from hardening a shoreline, and describes dune building as a more environmentally friendly and sustainable solution.

“Dunes are a good solution instead of having a pile of rocks that may or may not protect you over the long term, and are really ugly, if you want to be frank,” he said. “Building dunes, creating habitat, helping to recreate the natural environment and let it function for us as it has in the past. I think this is the next step down that path using natural solutions to the problems we generate by our desire to live right at the coast.”

The project is anticipated to run for three years at $70,000/year with support from the City of Tybee Island, through a grant from Georgia’s Department of Community Affairs, and from the US Army Corps of Engineers. Alexander hopes to identify and obtain additional funding to allow the project to continue throughout the typical seven-year span between beach renourishments.

Georgia’s living shore: UGA addresses coastal resilience from many fronts

By David Terraso

The coast has long been a place where the future happens first. Millennia before James Oglethorpe landed at Yamacraw Bluff on the Savannah River to found the Georgia colony, Native Americans, such as the Mokoma, Timucua and the Guale, had already introduced their civilizations to the area.

But on the coast, nothing is permanent—not the populations, not the vegetation. Not even the land.

Today, instead of vast marshes and uninterrupted coastal plains, there are neighborhoods, highways, commercial tracts and beach developments. There are shrimp boats and fish trawlers. There’s a shipping industry that boasts both the Port of Savannah—the fastest growing in the nation for the past 10 years—and the Port of Brunswick, the second busiest in the country for shipping motor vehicles.

Coastal Georgia is an ever-changing landscape that ebbs and flows in response to both natural and human-made forces. Scientists and researchers from an array of disciplines at the University of Georgia are dedicated to understanding how to balance those systems so the people of the state and visitors can enjoy them for years to come. UGA’s activities in pursuing coastal resilience run the gamut from educating the public to uncovering the latest science to helping communities withstand the physical and economic effects of the intruding sea.

Losing ground?

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Clark Alexander

For the majority of Georgia’s population, the coast is a place to come and have fun temporarily, to visit the sites and do a little fishing, shopping and beach-combing, before they go back home. But the people who live there depend on the coast’s resilience.

“The coastal ecosystems and coastal jobs are critically important for the economy of the state. That’s everything from seafood production to ecotourism to port activities,” said Clark Alexander, director of UGA’s Skidaway Institute of Oceanography.

The state’s seafood industry employs nearly 10,000 people, to the tune of $1.4 billion in sales, while the recreational fishing industry supports more than 1,400 jobs with another $140 million in sales.

Because many of the species in these two industries spend at least part of their life cycles in the marsh, Alexander said, it’s vital for business that coastal ecosystems stay healthy.

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Mark Risse

“Georgia has some of the best and most protected coastal ecosystems on the eastern seaboard. It has 14 barrier islands, and most are in long-term conservation,” said Mark Risse, director of Marine Extension and Georgia Sea Grantand Georgia Power Professor of Water Policy.

One of the biggest questions on the coast is how marshes will respond to the ongoing rise in sea level. Will they be able to withstand the ascending waterline, or will the Atlantic wash them away? According to photographic studies from the air, it looks like the marshes have been able to replenish themselves at the same rate the sea rises—so far. But models show the water’s pace is likely to increase.

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Sapelo Sea Farms employees sort and grade clams at the company’s dock in Townsend, Georgia. With support from Marine Extension and Georgia Sea Grant, owner Charlie Phillips began farming clams to diversify his business after the commercial shrimping and fishing industry began to decline. (Photo by Peter Frey)

“When we look forward, it’s a little scarier because we see the pace of sea-level rise increasing, and it means the marsh has to keep up. It’s going to have to sort of run faster to stay in place,” explained Merryl Alber, director of the UGA Marine Institute on Sapelo Island.


Merryl Alber, director of the UGA Marine Institute on Sapelo Island, is studying the impacts of sea-level rise that we can’t see. She and her colleagues are mapping what’s happening to coastal plant life underneath the soil. (Photo by Peter Frey)

Alber is working with research scientist Jessica O’Connell on a study mapping what’s going on under the soil in the marshes.

“There’s evidence that we might be losing ground that we’re not seeing when we look from above,” said Alber. “That could lead to the loss of that marsh, which would result in less carbon being stored by the plants.”

If plants aren’t able to store as much carbon, it will stay in the air where it could contribute to higher temperatures. What’s more, marshes are a nursery of nutrients for developing plant and animal life. Take away the marshes, and you wipe out a good portion of the base of the food web of the coast.

In the midst of mapping this loss, they’re trying to see if they can identify the most vulnerable spots and share it with the Department of Natural Resources to protect those areas.

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These drone images from the UGA Marine Institute show disturbances to sea wrack (seaweed) over time. Taken in three successive months in 2019, the photos show wrack disturbances in purple and provide information about the size, extent and amount of time that these disturbances last and what that means for the health of the salt marsh. (Image courtesy of UGA Marine Institute)

The resilience of a living shore

One way to help keep the coast resilient may be to convince developers to switch from using armored shorelines, made of steel, asphalt or concrete, to using natural materials like grasses, oyster shells, sand or rock in an array known as a “living shoreline.” Whereas armored shorelines simply keep the water at bay, sometimes just moving its destructive force down the coast, living shorelines can absorb the water.


Brian Bledsoe’s Institute for Resilient Infrastructure Systems works with state and local permitting agencies to help communities progress toward infrastructure systems that operate more in harmony with natural systems and are more tolerant to environmental disruptions. (Photo by Dorothy Kozlowski)

“Living shorelines can adjust and regenerate after a hurricane or a major storm. It may look a little beat up, but it’s going to patch itself back together using solar energy,” said Brian Bledsoe, director of UGA’s Institute for Resilient Infrastructure Systems (IRIS).“How many bulkheads that get hammered do you see building themselves back up?”

These shorelines work by trapping sediment in the water, which promotes plant growth. They also can absorb much more of the incoming waves, with a small portion of marsh absorbing a large portion of the wave energy, explained Bledsoe.

The living shorelines also protect those species that are a critical part of the costal ecosystem. Studies show an increase in fish, crabs and shrimp at living shorelines built by Marine Extension on Tybee, Sapelo and Little St Simons islands. Bagged oyster shells and native vegetation provided the base, with natural oyster reefs forming above. In addition to erosion control, the oyster shells improved water quality by naturally filtering pollutants from runoff.

“Living shorelines in Georgia are doing the job they were designed to do and have remained intact after storm events and continue to stabilize the shoreline,” said Tom Bliss, director of the Shellfish Research Lab at Marine Extension. “Continued monitoring will allow us to determine their longevity.”

Bledsoe is working on teaching permitting agencies up and down the coast about the benefits of living shorelines, which can work in concert with armored shorelines for a hybrid approach, making the system stronger overall.

“If you go down to your permitting agency and you want to get a permit for a bulkhead, they have a standard process and can issue those relatively quickly. It’s something they’re familiar with,” said Bledsoe. “But if you want to build a living shoreline, they’re not as accustomed to handling that. It’s often outside their comfort zone.”

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Living shorelines, like this one at Cannon’s Point Preserve on St. Simons Island, use natural materials like oyster shells, sand or rock to absorb some of the water and wave energy unleashed during a tropical storm or hurricane. (Photo by Courtney Balling and Tommy Jordan)

IRIS and the Marine Extension collaborate with state and federal agencies, as well as private partners, to raise awareness of living shorelines as a prudent investment. IRIS has proposed a resiliency plan to the National Fish and Wildlife Foundation for the backside of Tybee Island, which would create living shorelines along with natural pathways to move floodwaters in a way that reduces damage to infrastructure.

It’s a critical time, according to Risse. As shore communities like Tybee and St. Mary’s experience flooding during high tides, there’s a real concern that people’s homes and retirement nest eggs will be drowned. With the region expected to double in population over the next 40 years, helping communities understand the ongoing risk while creating sustainable development is one of its biggest challenges.

Marine Extension for years has been working with coastal communities to join the Consumer Ratings System (CRS), a Federal Emergency Management Agency program that reduces flood insurance premiums—sometimes by as much as 80 percent—for property owners in cities and counties that take action to exceed minimum floodplain management standards.

Tybee Island put $1 million into drainage improvements and began requiring new property owners to build at least one foot above the base flood elevation. As of 2017, Tybee Island property owners had saved more than $3 million in insurance premiums.

The troubles with floods

In addition to flooding from the sea, overworked stormwater systems can inundate the streets as well. Because these systems are designed to drain to rivers or the ocean, high tide can bring an intrusion of saltwater. When it rains, the basins are already partially full, giving the streets nowhere to drain.

Crumbling septic systems are one potential risk, said Alexander. As sea level rises, the coastal water table is pushed up, reducing the amount of dry soil the system uses to filter the waste and making it easier for disease-bearing materials to potentially contaminate drinking water.

An inventory of septic systems in an 11-county region along the Georgia Coast was completed by the Marine Extension last year. Risse and Scott Pippin, a faculty member with UGA’s Carl Vinson Institute of Government, are now working with the individual counties to determine which systems may be at risk and adding them to a public database.

In partnership with IRIS, Pippin has funding from the National Atmospheric and Oceanic Administration to use this septic inventory to assess present and future vulnerabilities in Bryan County, west of Savannah and home to the Fort Stewart Army Base. Bryan is also one of Georgia’s fastest-growing counties.

One way to create sustainable development is to use the marsh-front for parks and other public landscapes, so they are available for the entire community. This creates a more sustainable, living barrier than building housing right on the shore, said Jon Calabria, associate professor in the College of Environment and Design.

History is at stake as well. Calabria is working with the National Park Service, who, within a few years, will have to decide which historical seaside military forts it will try to save as the sea encroaches. “At some point, they may not be able to afford to maintain all of them just because the position they’re in is very vulnerable,” said Calabria. “If there’s an opportunity to redo some of the levees, that may buy them a few more years.”

Jill Gambill, coastal community resilience specialist at Marine Extension, helps communities and coastal residents plan for future incursions of the sea. Following Hurricane Matthew, Gambill led a series of focus groups in coastal communities to assess residents’ attitudes and behaviors related to evacuation. Using this information, Gambill produced materials to help better prepare coastal residents in the event of a storm, rolling out a YouTube video, social media and graphics to encourage residents to evacuate in advance of Hurricane Irma in 2017.

“One of the biggest take-homes is that storm surge is complex and there are lots of aspects to it,” Risse said. “We need to do a better job communicating what the risks are.”


Nik Heynen in geography is working with the Gullah Geechee community of Hog Hammock on Sapelo Island to reintroduce crops like sugar cane on the island. The project would help Hog Hammock residents become more self-sufficient and provide a boost to the community’s economy. (Photo courtesy of Nik Heynen

Environmental justice for all

Taking practical steps is very much influenced by one’s economic means, explained Alber. “One thing people are starting to key into is understanding the differences in people’s ability to respond to the challenges,” she said. “If you have more money and live in a flooded area, you can probably move. But if you don’t have a lot of money, it may be challenging. So there are some environmental justice questions.”

The identity and economic class of a community can have a significant effect on how much help and access they get to these solutions, said Nik Heynen, professor in the Department of Geography.

As part of UGA’s Cornelia Walker Bailey Program on Land and Agriculture, co-directed by Heynen and Sapelo Island business leader Maurice Bailey, Heynen spends a lot of time working with the island’s Gullah Geechee community of Hog Hammock. These direct descendants of people brought over as slaves from West Africa possess a unique culture. The community was once as large as 500 people but has dwindled to around 40. It’s a relationship that took a lot of time and care to build, Heynen said.

“Stripping assumptions about what people in the community want, opening lines of communications between people who respect each other and are willing to be honest, even when it’s difficult, [goes a long way],” he said.

Heynen works alongside residents as they reintroduce several crops, like sugar cane, that were once grown on the island. Currently, with five plots of land, one as large as 25 acres, they’re working it on a shoestring, using a lot more manual than mechanized labor.

“If we can get a tractor, it’ll really be a game-changer,” said Heynen.


The UGA Marine Education Center & Aquarium, located on Skidaway Island as part of the Marine Extension and Georgia Sea Grant, holds summer camps for elementary, middle and high schoolers, as well as internships and adult education programs for older students, to help the public learn about the flora and fauna of coastal ecosystems, in hopes of inspiring people to preserve and protect them. (Photo by Peter Frey)

Teaching the future

In Savannah, UGA’s Marine Education Center and Aquarium, part of Marine Extension, hosts kids aged 6 to 15 during the Summer Marine Science Camp and provides educational field trips to student during the school year, where they learn from scientists about the coastal ecosystem, sea life and local habitats. The aquarium also conducts adult education programs. Its offerings are designed around the concept that educating and familiarizing the public with the ecosystem will inspire people to preserve and protect their environment.

In addition, Marine Extension hosts internship programs for students, teachers and the public in topics such as aquarium science, water quality, shellfish, coastal septics and socioeconomic issues. College students take part in courses where they learn about and prepare for careers in the marine sciences and coastal management.

To help teach residents about the dangers of staying in place during an evacuation order, Sun Joo (Grace) Ahn, associate professor in the Grady College of Journalism and Mass Communication and director of the Games and Virtual Environments Lab, has created a virtual reality system that gives them a first-person experience of a hurricane.

“Virtual reality is particularly good at placing users in a situation that can be potentially fatal or even impossible in the physical world, in a way that’s very realistic to the senses,” said Ahn.

By experiencing a storm in a virtual world, Ahn is giving people a way to see just how dangerous a storm can be. Users can look in all directions and see the water entering a house and surrounding them with debris, mud and furniture, making it difficult for them to move, much less leave. At the end, the simulation shows what someone should do in such a situation.

“It’s a very visceral, frightening experience,” said Ahn.

The big picture

“One third of the salt marsh in the eastern United states is along our 100 mile coast and these marshes have a tremendous impact on the entire Atlantic ocean,” Risse said. “Key parts of our coastal food web including many fish and sea turtles originate in coastal Georgia and travel around the world.”

Add to that biodiversity, the cultural diversity of those who call the Georgia coast home, from the Gullah Geeche, the descendants of the European settlers, to the newcomers arriving from the four corners of the globe, and it’s clear that the coast is a lot more complex than previously understood. It takes patience, the ability to learn from what each other sees, and an openness to new ideas to fully comprehend how the natural world responds to the activities of humankind. One thing is sure: We’ll get a lot farther working the puzzle together than on our own.

That goes for scientists too.

“You have to learn your colleagues’ thought structures, their tools, models, how they view the world,” said Bledsoe. But it gives researchers a more holistic view of the region, so they can understand how everything works together. “It takes a lot of time, discussions and humility.”

New weather station goes online

UGA Skidaway Institute’s new weather station became operational in early May.

The weather station includes a 30-foot-tall tower on the pier at Priests Landing. It has a Gill Instruments GMX531 Weather Station, collecting wind direction and speed, air temperature, relative humidity, atmospheric pressure, solar radiation and precipitation at five minute intervals. The station is powered by a solar panel, and data is sent by a cellular link to a website for display. This installation is part of a National Weather Service-funded effort to improve regional weather forecasts.

The available current and historic data can be accessed HERE. Select “Skidaway 1,” which is the 14th station on the list.
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Connecting Georgia seafood producers to consumers during the coronavirus pandemic

by Emily Kenworthy

As farmers and food distributors struggle to get their products into the hands of consumers, UGA Marine Extension and Georgia Sea Grant has teamed up with UGA Cooperative Extension and the Georgia Department of Agriculture to generate business for the seafood industry.

Clams are cleaned before being sorted by size.

Photo credit: Pete Frey

The Ag Products Connection, a partnership between UGA Extension and the state agriculture department’s Georgia Grown program, is designed to connect farmers and seafood producers with customers around the state looking to source local food products. Businesses can sign up to have their companies promoted through the online platform, which lists local businesses by county.

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Photo Credit: Peter Frey

“The resource was developed for producers who had a glut of product. Some were selling to school systems or restaurants, but now they don’t have those avenues of customers,” said Tori Stivers, seafood and marketing specialist for Marine Extension and Georgia Sea Grant. “With this program, they can market directly to consumers who can serve as new source of revenue for them.”

Stivers is working with fisheries specialists in UGA Marine Extension and Georgia Sea Grant to promote the resource to seafood professionals, many based on the coast, who are dealing with a surplus of product during the pandemic. She recently shared the resource with a list of more than 150 seafood wholesalers in Georgia, encouraging them to sign up.

“My hope is that it provides some income to those who have seen their business drop during this time so they can keep as many employees on the payroll as possible,” Stivers said. “If they can supplement their business by going directly to consumers, it might help them stay open.”

Some seafood businesses, like Southside Shellfish in Savannah, have already signed up for the program.

“We’ve seen a decline in clientele, but we’re still here and we’re still operating,” said Hope Meeks, owner of Southside Shellfish. “That’s why I think this resource will be so good because people keep calling and asking if we’re open, which we are.”

Meeks’ business has been involved in commercial crabbing since 1991. The retail business began in 2007, with the opening of a market in south Savannah. In addition to local blue crabs, they sell black sea bass, snapper, flounder and other seafood native to the east coast.

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Photo Credit: Peter Frey

“I’m hoping that this will bring in our regular customers as maybe new customers that don’t already know we’re here,” she said. “We have raw and cooked seafood, so for those who are skeptical about eating out, this is great way for people to source shellfish and fish products you can catch in our area.”

Georgia’s seafood producers and wholesalers who are keeping regular hours, providing curbside pickup, home delivery or e-commerce sales during the COVID-19 crisis can join the program by visiting the Georgia Grown Ag-Products Industry Promotion  or Georgia Grown E-Commerce Promotion pages and filling out forms that will add their information to the statewide database of producers that is being shared with consumers and buyers.

Consumers can find seafood resources listed by county HERE.

Georgia Grown — a state membership program designed to help agribusinesses thrive by bringing producers, processors, suppliers, distributors, retailers, agritourism and consumers together — is waiving all membership fees for the service until July to help producers affected by the crisis.

UGA Skidaway Institute’s Edwards granted tenure

The University of Georgia has granted tenure to UGA Skidaway Institute of Oceanography / Department of Marine Sciences scientist Catherine Edwards. Edwards was also promoted from assistant professor to associate professor, effective Aug. 1.

OLYMPUS DIGITAL CAMERAEdwards is a physical oceanographer, with broad interdisciplinary interests in marine sciences and engineering. She earned a B.S. in physics with highest honors from the University of North Carolina at Chapel Hill, and worked as an ocean modeler at the U.S. Naval Research Laboratory before earning her Ph.D. in physical oceanography from the University of North Carolina at Chapel Hill. She joined Skidaway Institute in 2010.

Edwards’ research focuses on answering fundamental questions in coastal oceanography and fisheries sciences with autonomous underwater vehicles (AUVs). Using AUVs, also called gliders, she and her team are developing novel ways to optimize their use with engineering principles and real-time data streams from models and observations.

While at UGA Skidaway Institute, Edwards has been awarded more than $2 million dollars on 12 projects totaling more than $12 million from NOAA/Navy sources, the Gulf of Mexico Research Initiative and four different programs within the National Science Foundation. As the founder of a regional glider observatory, she serves as the lead scientist in a new project that places gliders in the paths of hurricanes to better predict their intensity at landfall. Edwards is a co-primary investigator in a large $5 million observational program studying exchange between the coastal and deep ocean at Cape Hatteras. In an effort funded by NSF’s Smart and Autonomous Systems program, Edwards is also working with researchers from Georgia Tech and Gray’s Reef National Marine Sanctuary to utilize gliders and acoustic tagging to track fish migrations.

Scientific serendipity: Researchers make surprising finding on ocean’s ‘thin layers’

Sometimes scientists start out researching one subject, but along the way, they come across something else even more interesting. This is what happened to University of Georgia Skidaway Institute of Oceanography researcher Adam Greer in the summer of 2016 when Greer was a post-doctoral associate at the University of Southern Mississippi. That fortuitous event resulted in a paper recently published in the journal Limnology and Oceanography with Greer as the lead author.

Adam Greer 1 650pGreer and his fellow researchers were on a cruise in the northern Gulf of Mexico to study the effects of river input on biological processes. They came across a natural phenomenon called a thin layer. These are oceanographic features found all over the world where biomass collects into a narrow portion of the water column–less than five meters thick vertically–and can extend for several kilometers horizontally. They tend to occur in stratified shelf systems.

“Surprisingly, there are few published studies on thin layers in the northern Gulf of Mexico, which is heavily influenced by rivers and highly stratified during the summer,” Greer said. “Thin layers are important because they are trophic hot spots, where life tends to congregate, and predators and prey interact.”

However, Greer said, thin layers are very difficult to analyze because they occur within a restricted portion of the water column, and most conventional ocean sampling equipment will not detect their influence on different organisms.

Greer and his colleagues were better equipped than most to study the thin layer. Rather than laying out a grid and taking a series of water samples, they were equipped with an In Situ Ichthyoplankton Imaging System (ISIIS). This imaging system was towed behind their research vessel and undulated through the water column, producing a live feed of plankton images and oceanographic data. By studying the video, they were able to map the distributions of many different types of organisms in great detail. The thin layer was composed of large chains of phytoplankton called diatoms and gelatinous zooplankton called doliolids.

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A crewman launches the ISIIS.

“Although we expected many different organisms to aggregate within the layer, this was not the case,” Greer said. “The only organisms that were concentrated within the layer were gelatinous organisms called doliolids. Other organisms that we expected to see, such as copepods, chaetognaths and shrimp, tended to congregate near the surface just south of the thin layer.”

The researchers determined that the area south of the thin layer was influenced by a surface convergence – two water masses colliding and pushing water downward at a slow rate. They believe that many organisms with active swimming ability, such as shrimps and copepods, could stay within the surface convergence, while more passive swimmers, such as doliolids would follow the trajectory of the thin layer and diatoms.

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An image from the In Situ Ichthyoplankton Imaging System passing through the thin layer. The long, slender filaments are chains of diatoms. The larger, oval plankton are doliolids

Greer and his colleagues discovered several other characteristics of the thin layer they had not anticipated. There was a higher concentration of live phytoplankton than expected. As a result, the thin layer also had a high concentration of dissolved oxygen due to the photosynthetic activity. The zooplankton were also aggregated into distinct microhabitats with different oceanographic properties — such as temperature, salinity and light. The microhabitats also contained different types and abundances of food.

“For a lot of these organisms, if you took the average abundance of food it wouldn’t be enough to survive,” Greer said. “So whatever mechanisms there are to create higher abundances of food, they are potentially really important for a number of different organisms.”

The other members of the research team were Adam Boyette, Valerie Cruz, Kemal Cambazoglu, Luciano Chiaverano and Jerry Wiggert, all from the University of Southern Mississippi; Brian Dzwonkowski and Steven Dykstra, from the University of South Alabama; and Christian Briseño‐Avena and Bob Cowen, from Oregon State University.
The paper can be viewed HERE.

UGA Skidaway Institute scientists participate in 2020 Ocean Sciences Meeting

The UGA Skidaway Institute of Oceanography was well represented at the 2020 Ocean Sciences Meeting in San Diego in February. The Ocean Sciences Meeting is the flagship conference for the ocean sciences and the larger ocean-connected community. The Ocean Sciences Meeting was co-sponsored by American Geophysical Union, the Association for the Sciences of Limnology and Oceanography, and The Oceanography Society.

Professor Marc Frischer said he was impressed by the efforts of the ocean science community to evolve the climate change dialog and narrative.

“As Margaret Leinen said in her closing plenary address, we started at ‘the ocean is too big to be affected’, to ‘the ocean is too big to fix,’ to where we are today, ‘the ocean is too important not to fix,’” Frischer said. “The call is for the ocean science community to become engaged in searching for solutions, and we have a lot to offer.” Leinen is the director of Scripps Institution of Oceanography.

Frischer presented some of his most recent work investigating the ecological significance of doliolids in continental shelf systems. In addition to that presentation, a student from Savannah State University, who worked in Frischer’s lab last summer, presented the results of work she conducted. Frischer mentored Ashly Rivera as part of Savannah State’s Research Experiences for Undergraduates program. At the end of each summer the REU students present their research and vote on who they think did the best job. The winner is awarded an all-expense paid trip to a science meeting of their choice. This past summer Rivera won that honor and chose to attend the Ocean Sciences Meeting. Ashly presented a poster titled “The Re-Acquisition of Shrimp Black Gill Infections by Penaeid Shrimp; Oceanic or Estuarine Sources?”

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Ashly Rivera (r) at her poster presentation.

Assistant professor Catherine Edwards co-chaired a session on western boundary current-shelf interaction. The session was inspired by her and fellow Skidaway Institute scientist Dana Savidge’s ongoing research into ocean currents around Cape Hatteras, “Processes driving Exchange at Cape Hatteras,” also known as PEACH. Edwards also presented a poster on the vertical structure of Hatteras and Gulf Stream fronts as part of a large group of PEACH researchers. She was a co-author on four other posters and two talks, including posters by Savidge and UGA Skidaway Institute research technician Ben Hefner. Hefner’s poster explored data from the multiple nested high frequency radars at PEACH, using different combinations of radials to get realistic data over Diamond Shoals at Cape Hatteras.

“With their high wave energy and treacherous conditions for sampling, the shallow waters of shoals are a very difficult places to get good data,” Edwards said.

Edwards’ poster looked at the vertical layering at the boundaries of Mid Atlantic Bight, South Atlantic Bight, and Gulf Stream water. “You see interleaving of up to five layers in just 20-30 meters water depth, which is important for exchange of heat and salt between the deep and shallow ocean,” Edwards said.

Assistant professor Adam Greer was the lead author and presented a poster titled “High-resolution sampling of a broad marine life size spectrum to examine shelf biophysical coupling.” He was also a co-author for three other posters and one oral presentation.

Associate professor Clifton Buck presented a poster titled “Aerosol trace element concentrations and fractional solubility in the North Pacific Ocean: US GEOTRACES GP-15 Pacific Meridional Transect.” He was also the co-author on an additional poster and two talks.

Professor Jay Brandes lead an oral presentation on “Variability of microplastics in estuarine systems and consequences for organism studies.”

“Studies of microplastic pollution have really taken off in the last couple of years,” Brandes said. “There were two solid days of talks and posters on the subject from around the world, from basic studies to community cleanup efforts. This level of interest would have been unheard of in past meetings.”

He was also a co-author for three poster presentations. Graduate student Kun Ma was the lead author on one of those poster presentations, “Constraining photochemical production rates of dissolved inorganic carbon in the open ocean using the moderate dissolved inorganic carbon (DI13C) isotope enrichment (MoDIE) method.”

Gray’s Reef explores sounds of the ocean with virtual learning

NOAA Gray’s Reef National Marine Sanctuary is working to continue to provide virtual learning opportunities while working from home. An ongoing collaboration between Exploring by the Seat of Your Pants and the Office of National Marine Sanctuaries hosted an hour-long webinar, Exploring the Sounds of Gray’s Reef, with Gray’s Reef scientists.

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Alison Soss and Kris Howard study the sounds of Gray’s Reef to track fish movements and species diversity. Monitoring sounds and movements of commercially important species like black sea bass helps guide management decisions in the region’s waters.

Kris Howard, Alison Soss, and Ben Prueitt provided an overview of the NOAA Sanctuary System and Gray’s Reef, including a virtual live aboard experience on the NOAA Ship Nancy Foster. Webinar participants could also hear audio from hydrophones listening for fish noises and acoustic receivers to track movement of black sea bass. The webinar concluded with a question and answer session from the at-home audience of students, teachers and the general public. The full webinar can be found at the YouTube channel for Exploring by the Seat of Your Pants

UGA Skidaway Institute scientists use high-tech tools to track fish migrations

UGA Skidaway Institute of Oceanography scientist Catherine Edwards is participating in a collaborative project that will track the migration patterns of important fish species using artificial intelligence and a fleet of underwater robots. The project is a joint effort among UGA Skidaway Institute, Georgia Tech, Michigan State University, Wright State University and Gray’s Reef National Marine Sanctuary.

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Technicians prepare to deploy a glider. Photo credit: Kim Donoghue

The researchers use a combination of two different types of autonomous underwater vehicles equipped with acoustic receivers. Edwards specializes in gliders — torpedo-shaped crafts that can be packed with sensors and sent on underwater missions lasting weeks. The gliders will join a group of six robotic fish designed by collaborators at Michigan State. Both types of robots will use their “underwater ears” to listen for the sound signals from fish that had previously been tagged with acoustic transmitters. The tags on each fish transmit a different sound signal, allowing the researchers identify fish movements over time and distance.

The gliders will monitor the density of the water which controls the speed of sound through it. Using that data, Edwards and her colleagues will be able to better locate the tagged animals as well as to identify the location of the gliders themselves — a problem that has been a significant challenge in underwater navigation.

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A Skidaway Institute glider named “Angus” begins a mission. Photo credit: Kim Donoghue

“Marine robots can be used to accurately map and track marine animals, which will lead to a better interpretation of their migration patterns,” Edwards said. “But because fisheries managers, oceanographers and roboticists have different perspectives and knowledge bases, it can be difficult to take advantage of cutting edge research in each field without a significant effort to translate among the groups.”

The overall goal of the project is to develop an interface that will translate the missions and needs of fisheries managers into multi-level planning for a fleet of marine robots to monitor fish populations in a dynamic coastal ocean environment. While preparing for the first field season, the team is developing an interface that uses artificial intelligence as a powerful tool to plan out the actions of the robots to identify hotspots based on these insights, helping their human pilots, and ultimately fulfilling the goals of fisheries managers.

“An important component of our work at NOAA’s Gray’s Reef National Marine Sanctuary is to study marine organisms’ use of the sanctuary, whether as a migration route, foraging location or other function,” said Stan Rogers, superintendent of the sanctuary. “The glider and robotic technology Dr. Edwards and her team will deploy in Gray’s Reef can help us track the movement patterns of animals that use the sanctuary and identify specific features of Gray’s Reef that are highly attractive to fish.”

The researchers hope to begin preliminary field testing this summer, depending on COVID-19-related restrictions.

The other members of the research team are Fumin Zhang from Georgia Tech, Xiaobo Tan from Michigan State University and Mike Cox from Wright State University.

The project is funded by a three year, $1 million National Science Foundation grant.

Marine scientists map fish habitats

by Alan Flurry

Beyond the barrier islands of coastal Georgia, the continental shelf extends gradually eastward for almost 80 miles to the Gulf Stream. This broad, sandy shelf largely does not provide the firm foundation needed for the development of reef communities to support recreational and commercial fish species including grouper, snapper, black sea bass and amberjack.

“Natural and artificial reef habitats are important to Georgia fisheries because they provide hard, permanent structure on the Georgia shelf, which is dominantly a vast underwater desert of shifting sands,” said Clark Alexander, professor and director of the University of Georgia Skidaway Institute of Oceanography. “The Georgia Department of Natural Resources has invested significantly over the past several years in developing the capacity to map these areas to enhance the management of these reef communities.“

To increase the availability of high-quality hard bottom areas off Georgia, the DNR began an artificial reef-building program in 1971 to deploy materials at various locations across the continental shelf, from 2 to 30 miles offshore. Reef materials include concrete slabs and culverts from road, bridge and building demolition, subway cars, ships, barges, and U.S. Army tanks. Because some of these reefs are far offshore and DNR resources are limited, the status of some of that material has not been examined for decades.

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A bathymetric survey of Ossabaw Sound.

For the past five years, Alexander has been leading an effort to improve understanding of marine, coastal and estuarine habitats and functions using high-resolution sonar to map state water bottoms, with funding from the DNR Coastal Incentive Grant program. Alexander’s team has amassed critical depth and habitat information for five of Georgia’s sounds (Wassaw, Ossabaw, St. Catherine’s, Doboy and Sapelo), revealing deeply scoured areas where underwater cliffs have formed to create hard substrate where complex ecosystems and biological communities have developed.

“These inshore, hardbottom habitats should enhance biodiversity in the areas near these structures and enhance ecosystems supporting both commercial and recreational species across the continental shelf,” Alexander said.

Alexander is currently leading a new, three-year project mapping important fish habitats in state waters — the newly discovered estuarine habitats, and artificial reef structures within 10 nautical miles of shore – those areas most accessible to recreational anglers, boaters and divers. In addition, his research group is mapping previously unmapped portions of the sounds and tidal rivers deeper than 15 meters to discover the extent of these newly identified estuarine hardbottom habitats.

Skidaway Institute researchers will work with DNR to update the online “Boater’s Guide to Artificial Reefs” with accurate locations and imagery of deployed materials for these reefs. These new, more accurate artificial reef surveys will also document recent changes in the locations and integrity of placed materials and verify the low-tide water depths over all features in the artificial reefs to enhance navigational safety.