Archive for the ‘Barrier Islands’ Category

UGA Skidaway Institute researchers study sand resources near the Georgia coast

January 7, 2016

If a hurricane hits the Georgia coast, a major priority for coastal communities will be finding sand to rebuild beaches destroyed by erosion. University of Georgia Skidaway Institute of Oceanography scientist Clark Alexander has received funding approval from Georgia Sea Grant for a two-year study to collect and analyze new, high-resolution data to identify the sand resources available near the Georgia coast.

In 2012, Hurricane Sandy caused billions of dollars in damages to communities along the east coast of the U.S. Coastal communities in Georgia are vulnerable to future storms, and some have begun to develop strategies to increase their resilience to such storms and to speed their recovery from one. When it comes to restoring storm-eroded beaches, those communities will require a detailed understanding of the locations and characteristics of the available sand resources they will need.

Beaches like Glory Beach on Jekyll Island may potentially benefit from the sand resource study.  Photo Credit: www.GoldenIsles.com

Beaches like Glory Beach on Jekyll Island may potentially benefit from the sand resource study.
Photo Credit: http://www.GoldenIsles.com

“Sand resources are needed to rebuild beach and dune systems to provide the same or better levels of protection to lives and property,” Alexander said. “These sand resources data are critically needed in Georgia, as the sand resources in our state waters are the most poorly known of all the states along the East Coast.”

The study will focus on three developed barrier islands that have not been renourished — Sea Island, St. Simons Island and Jekyll Island. The project will gather new samples and data on seabed sediment texture and composition from the beach out to the state-waters boundary, three nautical miles offshore. The researchers will merge that data with existing samples from the beaches and the sea bed and integrate all the samples to determine where sand deposits are located that would be suitable for beach renourishment.

“Typically, we find a wide range of sand, and not all of it is beach-quality,” Alexander said. “We need to locate sand deposits that have similar size and composition to the natural beach.”

The team will collect beach grain size samples during both the summer and winter to assess the differences in texture and composition in the beach in response to changing storm, tide and wave conditions.

The sea floor in the study region has not been comprehensively surveyed since the 1930s. Another part of the project will be to use an echosounder to collect data on the depth and morphology of the sea bed. This data will be used to create bathymetric maps of the ocean bottom. These maps will also identify regions of thicker sand deposits, which indicate greater volumes of sand.

The researchers will then combine the new information with existing data in a Geographic Information System tool to integrate the sand resource and bathymetry information and model the extent of beach-quality deposits in the Sea Island to Jekyll Island region.

The results of the project will be made available online to government officials, the management community and the general public on a number of Web sites, including the Georgia Coastal Hazards Portal (http://gchp.skio.usg.edu/) developed by Alexander.

Georgia Sea Grant is a unit of the UGA Office of Public Service and Outreach.

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An early morning TV story at UGA Skidaway Institute

September 22, 2015

WSAV TV and reporter Martin Staunton aired a story t his morning on Dr. Clark Alexander’s study on sea level rise on the Georgia coast.

http://wsav.com/2015/09/22/rising-sea-level-may-change-georgias-marshes/

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

August 27, 2015

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

UGA study finds high marine debris, need for standardized reporting along Georgia coast

February 3, 2015

Skidaway Island, Ga. – University of Georgia researchers are hoping to find a consistent way to record the marine debris—particularly pieces of plastic—crowding Georgia’s beaches as part of an effort to find a solution for the growing problem.

Marine debris has been washing up on Georgia beaches and uninhabited islands for years. Combatting the issue starts with figuring out how big it is, and a new two-part study from the UGA Skidaway Institute of Oceanography and Marine Extension published online in the Marine Pollution Bulletin finds that marine debris reporting can improve if it becomes standardized.

The problem right now is this: A volunteer group goes out and records the weight or volume of the marine debris collected. However, volunteers don’t often record the specific square feet measured or the contents of the debris. Due to a lack of report standardization, researchers often can’t compare the marine debris, especially plastic fragments, reported by different groups.

A sample of marine debris collected along the Georgia coast sits on a table at the UGA Skidaway Institute of Oceanography.

A sample of marine debris collected along the Georgia coast sits on a table at the UGA Skidaway Institute of Oceanography.

“We’ve seen plastic usage go up dramatically,” said study co-author Dodie Sanders, a marine educator and outreach coordinator for UGA Marine Extension, a unit of the Office of Public Service and Outreach. “It’s an important 21st century global issue. We need to learn more to better understand the issues of marine debris.”

The study’s lead author Richard F. Lee, professor emeritus with the UGA Skidaway Institute of Oceanography, agrees.

“Plastic debris is created on land and then it goes into rivers, flows into the ocean and washes up on land,” he said. “We’ve found that plastic debris ends up not only on populated beaches, but on inaccessible islands as well. We’ve found plastic everywhere on the coast.”

The first part of the study gathered debris from 20 sites along Georgia’s coast, including Tybee, Cumberland and Ossabaw islands. The debris was reported from volunteer organizations like Clean Coast, which hold monthly beach and marsh cleanups in Georgia.

Participants in a July 2014 teacher's workshop focusing on marine debris sift through the sands of Tybee Island in search of microplastic particles.

Participants in a July 2014 teacher’s workshop focusing on marine debris sift through the sands of Tybee Island in search of microplastic particles.

“The volunteer groups reported the weight of the debris, though we didn’t know the exact amount of plastic,” Lee said. “Based off the volunteer information we received, we did a follow-up study to more precisely measure the marine debris in a fixed location and period of time.”

The total collected debris ranged from 180 to 1,000 kilograms. The levels of plastic debris differed at each site over the course of the study, though plastic was consistently among the mix. Found plastic included plastic bottles, wrappers, food utensils and fragments of fishing gear.

Sanders spearheaded the second part of the study, where she and students collected plastic debris from Skidaway and Wassaw islands over a period of two years.

“While Dr. Lee did data analysis, I did some of the field work,” Sanders said. “We picked the two islands in the second part of the study because they were accessible sites where Marine Extension often takes students for marine education.”

For the fieldwork, Sanders and students visited the islands each month. They took inventory of what kinds of plastics were on specific areas of the coast.

“On about a monthly basis, I would take students to learn about debris and tally all the items on the islands,” Sanders said. “We took areas of 200 meters by 40 meters and recorded the items found. We also used GPS units to mark what areas we had done.”

The students, many of them in middle and high school, came from all over Georgia to assist. As part of Marine Extension, Sanders regularly teaches visiting students about marine life. When students volunteered to clean up, she tried to emphasize the issues surrounding debris.

“The bulk of the plastic comes from land,” Sanders said. “When people think of marine debris, they think of the ocean. I try to emphasize watershed concepts—what happens upstream ultimately gets downstream.”

“It can take years for plastic to degrade,” Lee said, adding, “80 percent of the plastic found at Wassaw turned out to be fragments. The fragments then spread and can have a number of environmental effects.”

Sanders says that since plastic debris is everywhere on the coast, it has to be addressed and reported efficiently to reduce its effects.

“There are proactive and reactive approaches to the issues of marine debris, and both are important,” she said. “We’ve been reactive so far by picking up debris. The proactive approach is our role in educating the public and researching the negative impacts of marine debris.”

The study was supported by the Georgia Department of Natural Resources Coastal Incentive Grant, NOAA Southeast Atlantic Marine Debris Initiative and the NOAA Marine Debris Program.

The full article on “The amount and accumulation rate of plastic debris on marshes and beaches on the Georgia coast” is available at www.sciencedirect.com/science/article/pii/S0025326X14008200#.

 

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.

Senator brings Climate Road Trip to Coastal Georgia

April 24, 2014

Clark Alexander joined with a team from UGA to help educate Rhode Island Senator Sheldon Whitehouse yesterday about coastal issues. Whitehouse visited Ft Pulaski here in Savannah and then traveled to the UGA Marine Institute on Sapelo Island as part of his Climate Road Trip through NC, SC, GA and FL. Whitehouse is immediately in front of the statue in the second row. Clark is second from the left in the blue shirt.

Senator Whitehouse on Sapelo Island with Clark Alexander and group from UGA.

Senator Whitehouse on Sapelo Island with Clark Alexander and group from UGA.

Nice newspaper article!

July 25, 2012

Mary Landers from the Savannah Morning News wrote a nice article on our marine plastics project.It appeared on the front page of Sunday’s issue. Thanks, Mary!

The reporters who went to Wassaw Island last week. Mary is wearing the straw hat on the far right.

News media trip to Wassaw Island

July 20, 2012

We took several reporters to Wassaw Island this week for a story on marine plastic debris. We’ve seen two TV stories thus far and expect a story in the Savannah Morning News, probably over the weekend.

Alice Massimi from WSAV-TV (NBC) in Savannah interviews UGA Marine Extension Service educator Dodie Sanders on the beach at Wassaw Island.

 

Plastics pollution a widespread problem on the Georgia Coast

July 5, 2012

No part of the Georgia coast is protected from pollution by plastics and other marine debris. That is one finding of a study conducted by Skidaway Institute of Oceanography scientists Jay Brandes and Dick Lee.

The scientists studied the collection totals from beach clean-up programs by environmental groups like Clean Coast and the Tybee Beautification Association and Rivers Alive. They found that while beach-sweep programs at populated spots like Tybee Island collect the most plastic, even sweeps in relatively remote locations like Cumberland and Ossabaw Islands collect a sizeable haul. A 2007 beach sweep on Tybee by the Tybee Beautification Association and Rivers Alive collected 5,400 pounds of plastic. In similar clean-ups by Clean Coast in 2009, volunteers collected 1,100 pounds on Cumberland Island and 750 pounds on Ossabaw Island.

The places with the largest amount of plastics accumulation were Tybee Island, Little Tybee Island, Turner’s Creek and Pigeon Island.

“It is interesting that some of the beaches receiving relatively low numbers of visitors, such as Blackbeard Island and Cumberland Island, still have relatively high amounts of plastic debris,” Brandes said. “This suggests that the source of plastics on remote beaches is the surrounding coastal waters that contain plastics from both inland and the coast.”

The Skidaway Institute researchers focused their attention on plastics for several reasons. Plastics tend to be very durable and persist in the environment for long periods of time.  Also, relatively small pieces of plastic can be a threat to marine animals. Fish sometime eat the plastics, which can block their digestive systems. Sometimes harmful contaminants tend to cling to plastic and can be ingested when the plastic is eaten.

“Plastics pollution has been getting a lot of attention recently, especially those large gyres, like the Great Pacific Garbage Patch,” said Brandes. “But most of those plastics are coming from land and that means that most of the plastic in our environment is going to remain near the shore.”

For this study, the scientists were restricted to analyzing data provided by the various beach clean-up groups. The problem is these groups are, understandably, usually more concerned about cleaning up the beach than sorting types of debris they collect. Based on earlier studies of marine debris and limited sorting that has been done during some cleanups, the research team worked under the assumption that one half of the total material collected was comprised of plastics.

The plastics problem is not limited to coolers and plastic cups. According to Brandes, many of the larger plastic objects eventually become broken down into smaller pieces, as tiny as a grain of sand. They may remain suspended in the water column. Brandes has found these micro-plastic particles while collecting samples for other projects.

“Right now, very little is known about what kind of impact these micro-plastics might be having on fish or other parts of the marine ecosystem,” said Brandes.

Students in the Marine Debris program weight some of the material they have collected on the north beach of Wassaw Island.

To help with the problem of understanding what kinds of plastics foul our beaches and marshes, Skidaway Institute scientists are collecting additional data on marine plastics and other debris though a cooperative educational program, “Marine Debris,” with the University of Georgia Marine Extension Service.

“Marine Debris” is a hands-on, interactive program that incorporates the topic of marine debris with an emphasis on plastic debris along the coast of Georgia. Students and their teachers are conducting shoreline marine debris surveys on Wassaw Island to determine types of marine debris, weight of plastics collected and accumulation rates for the designated site. The students are compiling the data using the National Oceanographic and Atmospheric Administration Accumulation Survey protocol. The data is being submitted to the Southeast Marine Debris Initiative data base.

Skidaway Institute researcher receives $377,000 grant to assess coastal vulnerability

February 3, 2012

Clark Alexander

Skidaway Institute of Oceanography scientist Clark Alexander has begun a multi-investigator project to assess the vulnerability of the Southeast Atlantic coast to future threats ranging from sea-level rise to shoreline erosion.

The project is funded by a $377,000 grant from the National Oceanographic and Atmospheric Administration. It is part of a larger, $1.06 million project awarded to the Governors’ South Atlantic Alliance (Alliance), to coordinate efforts in Georgia, Florida, South Carolina and North Carolina to develop a consistent method of assessing coastal threats in the four states.

“Our overall goal is to develop a process to evaluate our coast’s physical and economic vulnerability to hazards like sea level rise, flooding, storms, hurricanes and erosion, and do so in a uniform way throughout the region,” said Alexander.

A key component of the project is further development of a computer program called AMBUR. Originally created by Georgia Southern University’s Chester Jackson when he was a graduate student at Skidaway Institute, AMBUR is a powerful tool to evaluate erosion and accretion on a changing coastline.

“Dr. Jackson will enhance AMBUR’s capabilities so that it can be used to evaluate additional coastal characteristics,” Alexander said. “We want to include additional factors such as habitat, elevation, population density, economic valuation and different shoreline types.”

While Jackson is working on AMBUR, Alexander and his team will be collecting data on coastal physical, biological, demographic and economic parameters, while also meeting with coastal managers from the four states comprising the Alliance to determine which parts of the Southeast coast are most critically in need of assessment. Once identified, these areas will become the first coastal regions targeted for analysis with the new AMBUR tools.  When completed, the scientists will be able to present coastal managers with information and maps describing coastal vulnerability for at least a portion of each state. Future funding will be sought to expand the analysis to the whole southeastern coastal region.

“By its very nature, this project will identify the most vulnerable areas along the coast and will provide an unbiased analysis of the incentives and disincentives for development in those areas,” said Alexander.

The project is expected to run for 18 months.