GEORGIA
Georgia's coastline is among the least developed on the U.S. east coast. Acidification monitoring near Georgia's coast began in the late 1990s and has provided insights into changing carbon chemistry in this relatively undeveloped region. There have been recent efforts to legalize oyster aquaculture and grow the shellfish industry. How could acidification affect these efforts?
GEORGIA
CHEMISTRY
Federal, state and academic institutions have contributed to multiple ongoing acidification monitoring initiatives on Georgia's coast. The University of Georgia and University of Delaware have been measuring coastal carbonate chemistry since the late 1990's. In addition, the longest acidification time series on the U.S. East Coast is located in the Gray's Reef National Marine Sanctuary. Read about the monitoring efforts below or check out this primer on acidification first.
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IS CARBON DIOXIDE INCREASING? Coastal monitoring and the Gray's Reef mooring both point to an increasing trend for carbon dioxide in Georgia waters. The rate of increase is faster than what could be caused by atmospheric increases alone.
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WHY? Recent research has started to untangle the different causes of coastal acidification that could explain why CO2 is increasing in coastal Georgia waters at a rate faster than what can be explained by atmospheric increases. Scientists found enhanced break down of organic matter (like marsh grass) from warming can contribute significant amounts of CO2 to estuarine waters.
Monitoring Locations:
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GRAY'S REEF NATIONAL MARINE SANCTUARY: The Gray's Reef mooring is 40 nautical miles Southeast of Savannah and has operated since 2006 as a joint effort by NOAA's Pacific Marine Environmental Laboratory, NOAA's National Data Buoy Center, the University of Georgia and the University of Delaware. Check out the mooring data here.
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GEORGIA LONG TERM ECOLOGICAL RESEARCH SITE (GA-LTER): The GA-LTER has collected water chemistry data at select stations since 2002. View available data here (search metadata text for: "dissolved inorganic carbon").
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UNIVERSITY OF GEORGIA/UNIVERSITY OF DELAWARE: Dr. Wei-Jun Cai's laboratory has been engaged in carbonate chemistry sampling in coastal Georgia since the late 1990s. Access Dr. Cai's publications here.
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ECOA: The East Coast Ocean Acidification (ECOA) cruise (formerly the Gulf of Mexico and East Coast Carbon Cruise) passes by once every 3 years with a transect off the Georgia coast. The research cruise is supported by the National Oceanic and Atmospheric's Ocean Acidification Program. Learn more about their monitoring efforts here.
GEORGIA
BIOLOGY
Though chemistry data is relatively abundant in coastal Georgia, there has been no research evaluating the impacts of acidification on Georgia's shellfish. What can we learn from other areas and what about coral at Gray's Reef?
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OYSTERS: Studies in other regions have found significant vulnerabilities in larval and juvenile shell mineralogy as well as some effects on metabolic rates. Though oyster reproduction appeared to be resilient to open ocean projections of pH change, “severe” treatments (pH 7.1) showed significant effects to reproduction with female reproduction particularly vulnerable. These extreme conditions are not uncommon in coastal Georgia marshes and could result in bottlenecks for oyster populations.
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CLAMS: Like oysters, there has been no research on clams in Georgia but studies in other regions show larval declines in survivorship and delayed development in acidification experiments. Research in 2017 found that low pH (7.3) reduced survival of larval clams but that diurnal (every 12 hour) fluctuations of pH (about 7.2 to 7.9) did not impact survival or growth larval or juvenile clams. When scientists paired these fluctuations with changing oxygen, a condition similar to those experienced by clams in estuaries, they found survival was significantly reduced.
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CORAL: Most of the corals that occur in Gray's Reef National Marine Sanctuary are "soft corals," or sea fans, that will likely be less affected by acidification than their hard reef-building counterparts. There are small occurrences of the reef-building coral Oculina and research is currently being conducted at UGA to understand potential acidification impacts to these corals in the Sanctuary.
GEORGIA
SOCIOECONOMICS
Once among the largest in the nation, Georgia's shellfish industry collapsed in 1940s due to over harvesting. As the aquaculture industry expands, there are opportunities to include acidification in planning and mitigation efforts.
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OYSTER HARVESTING: All oysters commercially sold in Georgia are currently wild caught but recently proposed legislation would allow aquaculture. In efforts to revive the industry, the University of Georgia in partnership with Georgia Sea Grant, opened a hatchery in 2015. Learn more about Georgia's plans to expand oyster industry here. Existing carbonate chemistry data could help inform locations for leasing and potentially timing of operations.
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CLAM AQUACULTURE: There is a small, but profitable, clam aquaculture industry in Georgia that has tripled in value over the last decade. Clams are grown in mesh bags for up to 24 months on mud flats before being harvested; these mud flats are where we would typically see the highest levels of carbon dioxide because of respiration (or organisms breathing out CO2, just like we do). Above we explained acidification from enhanced respiration but we do yet know how this could affect clam aquaculture operations.
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SOCIAL VULNERABILITY: Georgia's current social vulnerability to acidification impacts is considered low because of the small shellfish aquaculture industry. As Georgia seeks to expand this industry, there are opportunities to consider acidification mitigation and adaptation to maintain a resilient community.
WHO ARE THE SCIENTISTS?
Scott Noakes
University of Georgia
Dr. Noakes is a Research Scientist at The University of Georgia’s Center for Applied Isotope Studies (CAIS). He has been involved with ocean acidification/CO2 monitoring, paleontological and surficial geologic studies at Gray’s Reef and surrounding areas for the past two decades. His home department at UGA is involved with marine environmental surveys in estuarine and coastal regions and utilizes isotopic, elemental and organic analytes. CAIS also houses an accelerator mass spectrometer used in carbon dating organic-based samples such as shells and bone fragments, many of which have come from the Gray’s Reef area. In addition to his work at CAIS-UGA, he is also the Director and Diving Safety Officer of the University System of Georgia Scientific Diving Program, an AAUS organizational member.
Wei-Jun Cai
University of Delaware
Dr. Cai is a Professor at University of Delaware's College of Earth, Ocean and Environment. He has worked on marine carbon cycling for more than 25 years. His research areas include CaCO3 dissolution and sediment diagenesis in deep sea using microelectrodes (oxygen, pH and pCO2) and air-sea exchange of CO2 and carbon cycling in coastal oceans. Most recently, his research focuses on the responses of coastal ocean carbon cycle and ecosystem to a changing terrestrial export of carbon and nutrients as well as bottom-water acidification in estuaries and coastal oceans.
Janet Reimer
University of Delaware
Dr. Reimer is a biogeochemist at the University of Delaware working for Dr. Wei-Jun Cai with a focus on the marine carbonate system, CO2 air-sea exchange, and ocean/coastal acidification. Her research focuses on the state of ocean acidification on South Atlantic Bight shelf, in the coastal region, and inland waters. Recently, her research has been devoted to long-term increases in surface CO2 and related increasing acidity across the region. She also has expertise in data acquisition and management as well as synthesis projects combining spatial and temporal data. Janet collaborates on the Georgia Coastal Ecosystems Long-Term Ecological Research project in Georgia coastal marshes and coastal zone.
Chris Hintz
Savannah State University
Dr. Hintz is a Professor at Savannah State University's Marine Sciences Program. As a carbonate chemist and aquaculturist, Dr. Hintz studies marine biomineralization, ocean acidification, and inorganic carbon cycling/transport from estuaries and tidal creeks to the deep sea. His laboratory research utilizes high-precision pCO2-controlled-culture systems growing a variety of biomineralizing organisms and phytoplankton to investigate impacts of ocean acidification. His field research focuses on elucidating temporal and spatial variability of estuarine DIC export to the coastal ocean. Further, his analytical research combines these two by developing laboratory techniques and field-deployable instruments to improve data collection.