CCU Groundwater and mapping trip - Spring 2013 Dr. Richard N. Peterson Coastal Carolina University

Center for Marine and Wetland Studies 1270 Atlantic Avenue, Room 111 Coastal Carolina University Conway South Carolina 29526 USA

rpeters2@coastal.edu Georgia Coastal Ecosystems LTER Project

Dept. of Marine Sciences University of Georgia Athens Georgia 30602-3636 USA

gcelter@uga.edu https://gce-lter.marsci.uga.edu/ Dr. Richard N. Peterson Coastal Carolina University

Center for Marine and Wetland Studies 1270 Atlantic Avenue, Room 111 Coastal Carolina University Conway South Carolina 29526 USA

rpeters2@coastal.edu Principal investigator Matthew Carter Coastal Carolina University

Center for Marine and Wetland Studies 1270 Atlantic Avenue Coastal Carolina University Conway South Carolina 29526 USA

mlcarte2@g.coastal.edu Co-investigator Dr. Richard F. Viso Coastal Carolina University

Center for Marine and Wetland Studies 1270 Atlantic Avenue Coastal Carolina University Conway South Carolina 29526 USA

rviso@coastal.edu http://ww2.coastal.edu/rviso/ Co-investigator 2026

Our goals for this field effort will be two-fold: (1) use geochemical (radon) time-series measurements at various locations in the Duplin River to assess groundwater inputs to the Duplin; and (2) continue to expand the bathymetric mapping effort in progress through Doboy Sound. 1. For the radon effort, we will establish time-series locations for radon and water level measurements from existing docks at Marsh Landing, Lumber Landing, and Moses Hammock. A submersible bilge pump will be suspended ~1m below the water surface and continuously pump river water to an air-water equilibrium spray chamber. Water will drain from this chamber back to the river. This spray chamber will be connected in a closed air-loop with a radon-in-air monitor that will measure radon levels in the air stream passing through the spray chamber. The bilge pump will be powered from car batteries that will be changed and charged twice daily. In addition, a water level logger will be deployed to the river bottom at each location attached to a heavy weight and connected to the dock by a rope. Finally, we will collect 6-L groundwater grab samples from existing piezometers at Moses Hammock. For this effort, we will use a self-contained peristaltic pump and tubing to collect the water into our gas tight radon analysis bottles. 2. The bathymetric mapping effort will be constrained to our 26' Privateer research vessel. A base station will be established at the benchmark at the Sapelo Post Office, and our shipboard instruments will communicate with that. The Privateer will drive along a pre-determined survey path in Doboy Sound and use multibeam swath echo sounding to measure the bathymetry in the Sound.

Area 2: Patterns within the Domain (more information)

marsh subterranean water column/neritic depth salinity temperature water flow LTER NSF GCE chemistry geophysics hydrography pore-water chemistry Overall geographic extent of the research project -81.297445 -81.258908 31.497026 31.416399 2013-03-10 2013-03-16

GCE-LTER sub-award for groundwater quantification, NSF, $75K

estuary marsh complex Hunt Camp - Barrier island/marsh site on western Sapelo Island. This site is located at the upper reaches of the Duplin River, and is within the Sapelo Island National Estuarine Research Reserve. Existing well fields border small marsh area to northwest, some wells have been installed to south end of hammock where marsh is more extensive and permanent plots are located. Two existing hydrographic sondes and weather stations within this site are operated by SINERR (Hunt Camp dock) and UGAMI (flume dock). -81.295506 -81.258908 31.497026 31.462320 Marsh Landing - Marsh landing, where the Georgia DNR ferry docks on its route between the mainland (Meridian) and Sapelo Island. -81.297445 -81.294606 31.418899 31.416399 LumberLanding - Lumber Landing dock on the Duplin River at Sapelo Island, Georgia -81.277455 -81.277455 31.459769 31.459769 Map (Google Earth KML/KMZ or map image) https://gce-lter.marsci.uga.edu/private/registration/files/Maps/GCE-40-2013_Maps_CCU_Groundwater_and_mapping_Spring_2013.kml

Dock at Marsh Landing: 31°25'4.11"N 81°17'46.51"W Dock at Lumber Landing: 31°27'35.92"N 81°16'38.46"W Dock and piezometers at Moses Hammock: 31°28'44.14"N 81°16'23.11"W

1 plastic box will be deployed at each of the 3 docks for 5 days. The box will contain the radon measurement gear and batteries powering the bilge pumps. At each dock, a bilge pump will be suspended in the water ~1m deep, and a weight will be deployed to the bottom that houses a water level logger. All equipment will be completely removed at the conclusion of the 5 day field effort. FOr the bathymetric mapping, a ~2m tall tripod will be setup on the benchmark in front of the Post Office during daylight hours and will be removed at the conclusion of the fieldwork.