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Omnibus FY04-06 Research Projects
Omnibus FY02-04 Research Projects

Omnibus FY04-06 Research Projects

Title: Succession of Tidal Freshwater Wetlands on the Cooper River, SC: Ecological Functions and Management Alternatives.

Investigator(s): Dr. James Morris, University of South Carolina
Morris@sc.edu

Description: Management of coastal wetland impoundments is a major program area for the Consortium. They have economic importance at the state and local level and are of intense interest to resource management agencies and private stakeholders (e.g., owners of former rice plantations). Investigators will test a number of hypotheses as well as a mechanistic spatial simulation model of wetland succession based on six years of previous research supported by Sea Grant in South Carolina. Project objectives are to: (1) test the hypothesis that impoundments are a significant component of dissolved oxygen dynamics of the Cooper River System; (2) test if sediment accumulation rates differ by community and standing crop biomass; (3) test the hypothesis that optimum depth and growth ranges will differ by dominant plant species; (4) further develop the mechanistic spatial simulation model; and (5) characterize the ecological consequences of management alternatives that are of interest to resource managers and stakeholder groups along the Cooper River, South Carolina. The study area is of high interest because rapid succession of plant communities is occurring in more than 2500 ha of impoundments due to a reduction in freshwater discharge that was engineered in 1985. Their model, using Matlab and ArcView GIS technologies, will be used to forecast the effects of impoundment management activities under a variety of scenarios. Information and feedback gathered from workshops and briefings with state and federal natural resource agencies have shaped the nature of this final phase of the Cooper River Impoundment Project.

Investigator(s): Dr. Alan Lewitus, SCDNR, and Marianne Burke, USDA & College of Charleston
lewitusa@belle.baruch.sc.edu; burkem@cofc.edu

Description: The investigators will investigate the effectiveness of vegetated buffers in reducing nonpoint source pollution in stormwater detention ponds. The issue of stormwater detention ponds is of growing concern as explosive growth has put greater pressures on coastal ecosystems, and as many existing South Carolina stormwater detention ponds may not be environmentally friendly, sustainable, or cost-effective. The proposal will test the use of riparian vegetative zones as a mitigation or prevention strategy to improve pond water quality and consequently extend stormwater detention pond “life.” Specific objectives of the project are to: (1) design and install a riparian wetland peripheral system and ecotonal marsh for stormwater processing, and retrofit subterranean stormwater drains to channel water to upslope locations; (2) determine pre- and post-manipulation water and nutrient budgets of the watershed and ponds; and (3) quantify the effects of the vegetative buffer system on wetland nutrient flux and pond water sediment quality indicators. Anticipated benefits include a reduction in dredging frequency or other mitigation needs warranted by sediment contamination or accumulation. This effort should result in dividends to homeowners, property managers, homebuilders and other taxpayers.

Investigator(s): Dr. Robert Feller, University of South Carolina
feller@biol.sc.edu

Description: The project will examine the effects of blue crab (Calinectes sapidus) predation of periwinkle snails (Littoraria irrorata) on the health of the salt marsh cordgrass, Spartina alterniflora. Recent drought in the southeastern United States has prompted increased public attention to the ecological role and management of freshwater input to estuaries, and the questions raised regarding the potential relationship between the declines in blue crab populations and cordgrass die-off in southeastern estuarine systems. This research will challenge current dogma which states that Spartina is nutrient-limited. The investigator notes that recent caging studies suggest that snails are capable of grazing Spartina to the bare sediment if left unchecked by blue crab predation. The objectives of this study are to: (1) revalidate antiserum specificity and sensitivity; (2) measure prey detection time in controlled feeding experiments; (3) perform cage inclusion experiments; (4) census periwinkle population; and (5) conduct field collections of blue crabs and periwinkles for immunoassay of gut contents. Antiserum testing and gut contents immunoassays based on micro-Ouchterlony double immunodiffusion techniques will be used to test the alternative hypothesis that a trophic cascade regulates Spartina growth. Data will establish whether the trophic cascade from top-down control is sufficiently strong to regulate cordgrass.

Investigator(s): Dr. Richard Zingmark, USC, and Dr. Alan Lewitus, SCDNR
zingmark@biol.sc.edu; lewitusa@belle.baruch.sc.edu

Description: The investigators will study the functional relationships – called “coupling” – between epiphytic microalgae and foodwebs in a saltmarsh estuarine system. Their objectives are to: (1) quantify the grazing rates of microzooplankton, mesozooplankton, and benthic suspension feeders on phytoplankton, and qualitatively determine the types of phytoplankton being grazed; (2) demonstrate and quantify trophic coupling between the phytoplankton and epiphytic communities to determine important intermediate trophic links, and identify fish and shellfish species of economic and recreational importance; and (3) strengthen the scientific basis of the management strategy of protecting Spartina alterniflora marshes based on the hypothesis that they play a key functional role by harboring a productive epiphytic algal community that is trophically coupled to the production of important fisheries. The research will fill in gaps of our knowledge of estuarine secondary production. This project has a Year 2 (March 1, 2005) start date.

Investigator(s): Dr. David Owens, College of Charleston
owensd@cofc.edu

Description: Diamondback terrapins (Malaclemys terrapin) are the subject of a project of this study. The P.I. will test the hypothesis that the diamondback can prove to be a powerful sentinel species to help track the accumulation and degradation of contaminants in estuarine and coastal environments. Objectives of this study are to: (1) determine relationship of mercury contamination to the terrapin’s food supply (Litttorina); (2) compare mercury levels in the blood and keratin of terrapins to known coastal distributions of high mercury input, low DO, and high fish mercury concentrations; (3) determine if non-lethal sampling of blood can lead to developing an Index or Recent Exposure (IRE); (4) test laser ablation technique for chronological mercury determinations; (5) determine if bioaccumulation occurs; (6) test validity of non-lethal techniques; and ultimately (7) determine if terrapins are suitable for use as sentinel species for environmental monitoring purposes. Mercury levels will be measured at the NIST laboratory at the Hollings Marine Lab using the isotope dilution cold vapor inductively coupled mass spectrometry method.

Omnibus FY02-04 Research Projects

Title: Linkages Between Cellular Biomarker Responses and Reproductive Success in Oysters (Crassostrea virginica) and Mussels (Geukensia demissa)

Investigator(s): Dr. Amy Ringwood, S.C. Department of Natural Resources
RingwoodA@xiphias.MRD.DNR.State.SC.US

Description: This project addresses the serious concerns regarding the long-term chronic effects of inputs associated with anthropogenic activities on marine ecosystems and biological resources. It focuses on studying methods of testing and validating promising cellular biomarkers. The study has the potential to yield tools that will identify individuals and populations of two common estuarine bivalve species, the oyster Crassostrea virginica and marsh mussel Geukensia demissa, which are experiencing chronic stress. Also being addressed are the reproductive and recruitment effects of pollutants.

Investigator(s): Dr. James T. Morris and Dr. Henry McKellar, University of South Carolina; Dr. Joe Kelley, The Citadel
morris@sc.edu; hmckellar@sph.sc.edu; KelleyJ@Citadel.edu

Description: In this ongoing study, researchers will refine a model of plant succession of tidal freshwater wetlands on the Cooper River, South Carolina. The researchers will continue examining former rice fields, which are changing rapidly due to human intervention. Information from this project will be provided to state and federal natural resource agencies as they address management of impoundments. Rates of succession change from shallow habitats dominated by submergent aquatics to intertidal systems dominated by emergent marshes have been documented. The study has also determined that emergent marshes are sinks for N and P nutrients compared with earlier successional stages. Indications are that water quality function of the fields changes greatly with succession.

Investigator(s): Dr. Joseph Staton, Dr. G.T. Chandler, Dr. J.M. Quattro and Dr. B.C. Coull, University of South Carolina – Belle W. Baruch Institute
jstaton@sc.edu; chandler@sph.sc.edu; quattro@mail.biol.sc.edu; bccoull@sc.edu

Description: This research team will use the copepod Amphiascus tenuiremis as an estuarine model, aiming to understand the potential risk of a new pesticide, and develop a monitoring tool for fipronil, a newly approved and highly toxic pesticide. Fipronil is being used in areas adjacent to estuarine systems in South Carolina, such as golf courses. The researchers intend to produce resistant lines of A. tenuiremis to fipronil as well, and carry out breeding experiments to test for heritability of pesticide resistance.

Investigator(s): Dr. Timothy Shaw and Dr. Thomas Chandler, University of South Carolina
Shaw@mail.chem.sc.edu; chandler@sph.sc.edu

Description: The researchers will develop exposure-toxicity risk assessment tools based on the bioaccumulation of heavy metals in the benthic foraminiferan Ammonia becarii, and toxic response of the common benthic copepod, Amphiascus tenuiremis. Ultimately, coastal managers could use information gathered during this study to better determine new approaches to toxic site cleanup.

Investigator(s): Dr. Willard Moore, University of South Carolina
moore@geol.sc.edu

Description: This study addresses the effects on coastal water quality and ecosystem health resulting from coastal land-use change. This research project, a joint effort with Georgia Sea Grant, will determine the nutrient flux of groundwater and impacts on various biological processes in tidal creek waters in the Satilla River (Ga.) system. The proposed work will provide answers to basic questions about coastal ecosystem health, and complements the Consortium’s Land Use-Coastal Ecosystem Study (LU-CES), funded by the NOAA Coastal Ocean Program.

Principal Investigator(s): Dr. Loren Coen, South Carolina Department of Natural Resources

Description: The purpose of this research is to test whether intertidal oyster reefs play an important role in southeastern estuarine ecosystems. Their role as nursery habitats is but one example. Results will be used in formulating habitat management practices, as well as in developing restoration and mitigation methodologies.

(mpg file 1.3MB)  Quicktime video clip of Oyster Reef Restoration project

Principal Investigator(s): Dr. James Morris, University of South Carolina

Description: This research focuses on the ecological values of different successional stages of plant communities within the Cooper River's former rice fields. Human intervention and manipulation have affected this river system since the early 1700s when rice was cultivated by way of a dike and trunk system. In 1985, rediversion of the river changed basin water levels and influenced the succession of plant communities. This research addresses the following major questions: Do wetland nutrient budgets change with successional stage? What are the biogeochemical properties of different successional stages? What are the habitat values for fish of different successional stages? What are the rates and causes of succession? These questions concern landowners, conservation groups, and sportsmen.

Principal Investigator(s): Dr. Joseph Staton, University of South Carolina

Description: Researchers will identify, isolate, and characterize the GABA receptor gene from the marine nematode Cylindrotheristus miamiensis. Effects of pesticide exposure on the nematode's genetic composition will be examined under laboratory conditions, as well as in field experiments (for correlation to laboratory results). Using PCR technology, this work will complete the first step in developing an ecologically relevant model for evaluating pesticide runoff's effects on benthic organisms.