Georgia's coastline is among the least developed on the U.S. east coast. Acidification monitoring within Georgia's coastal marshes began in the late 1990's and has provided insights into changing carbon chemistry in this relatively undeveloped region. There have been recent efforts to legalize aquaculture within the marshes and grow the shellfish industry. With a limited number of subtidal and intertidal lease sites becoming available in Fall of 2022. How could acidification affect these efforts and what impact will acidification have on the local economy?
Research and Partnerships Around Georgia
Impacts to Organisms
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.
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.
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. Recent research has shown that this species is likely resilient to "moderate" acidification.
GEORGIA COASTAL ECOSYSTEMS LONG TERM ECOLOGICAL RESEARCH SITE (GCE-LTER): The GCE project has collected water chemistry data at select stations since 2002. View available data here (search metadata text for: "dissolved inorganic carbon").
ECOA: The East Coast Ocean Acidification (ECOA) cruise (formerly the Gulf of Mexico and East Coast Carbon Cruise) passes by once every 3-4 years with a transect off the Georgia coast. The research cruise is supported by the National Oceanic and Atmospheric Ocean Acidification Program. Learn more about their monitoring efforts here.
GRAY'S REEF MAPCO2: In July of 2006, a Moored Autonomous pCO2 system consisting of CO2, pH, temperature, and salinity sensors was installed on a National Data Buoy Center mooring within the National Marine Sanctuary. These sensors take measurements every three hours. To learn more about this project visit the Gray's Reef Affiliated Research page.
OYSTER HARVESTING: In efforts to revive the industry, the University of Georgia in partnership with Georgia Sea Grant, opened a hatchery in 2015. More recently, the Department of Natural Resources implemented a commercial shellfish leasing program within the Georgia marshes. Existing carbonate chemistry data could help inform locations for leasing and potentially timing of operations.
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. Mudflats are where we would typically see the highest levels of carbon dioxide because the large quantity of organic material in the sediments are broken down by bacteria that naturally release CO2 through biological processes.
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.
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.
Research has shown that CO2 is increasing at this site and that pH is decreasing. It is not clear yet if organisms off the coast in the South Atlantic Bight off Georgia are experiencing negative impacts due to pH. However, studies from other regions indicate that in organisms will eventually show signs of stress due to low pH. Further studies of organisms in this ecosystem are needed.
Other research being conducted within the sanctuary can also support acidification research since many species are affected by pH declines.