Sapelo Research Application Form
Research Application ID: GCE-157-2026 (submitted: 07/06/2026, status: approved)
Provide a brief title for web display
GCE Mesocosm Inundation Experiment
Investigator Information
On Island Sponsor: GCE SINERR UGAMI GADNR
| Principal Investigator: | Merryl Alber | ||
| Home Institution: | University of Georgia | ||
| Award Information: | GCE-V | ||
| Mailing Address: | Dept. of Marine Sciences | Phone Number: | (706) 542-5966 |
| University of Georgia | E-mail Address: | malber@uga.edu | |
| Athens, Georgia 30602-3636 | |||
| Co-investigators: | Jimmy Nelson (University of Georgia), Craig W. Osenberg (University of Georgia), James Byers (University of Georgia), Amanda C. Spivak (University of Georgia) | ||
Briefly describe the project goals and methodology
We are using a mesocosm array to test how variability in inundation affects marsh processes. The set-up involves 15 Uline H-3886 IBC tanks (48x40x46"; 275 gallons). Tanks are plumbed to receive water from the UGAMI seawater system and are set up to fill to a constant height (24"; 200 gallons) for varying lengths of time before draining back into South End Creek.
Tanks are programmed to fill during high tide to allow us to control both inundation time and variability.There are 5 treatments (3 mesocosms each), flooded as follows on each high tide:
1) 0.5 h
2) 3 h
3) 5.5 h
4) 3 +/- 0.5 h (flooding in this treatment will vary from 2.5 to 3.5 h)
5) 3 +/- 2.5 h (flooding will vary from 0.5 to 5.5 h)
We will place 16 tree pots within each tank (6" wide x 12" high). There will be 4 tree pots with each of the following: Spartina (1 plant); Spartina (1 plant) + mussels (3 mussels); mud alone; mud + mussels (3 mussels). Tanks will also have a hobo logger to record temperature and serve as a way to track inundation.
The experiment will run for several months (July through October 2026). We will measure plant above-ground and below-ground biomass, mussel growth and condition, pore water nutrients, and gas exchange at the end of the experiment. We hypothesize that a) plant growth will peak at intermediate inundation levels; b) mussel growth will peak at the highest inundation level; c) pore water sulfide concentrations will increase and redox will decrease with increasing inundation; d) plant and mussel performance will decrease with increasing variability; e) pore water concentrations and gas exchange will be more variable with increasing variability in inundation. This experiment will provide critical information regarding the underlying mechanisms of marsh response to changing inundation patterns.
Where will the project be located?
The mesocosms are located on the upland near the UGAMI seawater system facility, at the edge of South End Creek. The return pipe is located at 31.3975602, -81.2815393
How will you provide GPS coordinates for study sites?
GPS coordinates are listed in the project location field
What are the expected start and end dates of the project?
Start Date: 07/10/2026 End Date: 10/31/2026
How many people will access the site and at what frequency?
2-3 people will be at the site daily during set-up and break-down (all on the upland); 1 person will be on the site daily to check on the system (on the upland).
Keywords that describe your project
What equipment will be deployed in the field?
The mesocosms are located on the upland and so not in a jurisdictional area. However, there is a 4" PVC pipe serving as a common outlet for all tanks that returns seawater to South End Creek (< 100 feet from the intake). The pipe is lying on the marsh surface and will release ~ 3,000 gallons of seawater on the falling tide when the experiment is running. The water that is released will not go into the marsh but rather directly into the creek. (See figures)
Will plants or animals be collected as part of this study?
Approximately 200 Spartina plants were collected in March 2026 from the marsh near Lighthouse Creek and potted into individual tree pots. Approximately 400 mussels were collected in June 2026 from Airport marsh. This information will be included in the UGAMI collecting permit.
What are the likely impacts of the project on the site?
The Spartina adjacent to the bulkhead at South End Creek was disturbed when the return pipe was set up. We estimate the area will recover after 1 growing season once the pipe is removed.
Will the project design include boardwalks? If not, explain why not.
How long will impacts persist after the research is concluded?
One growing season.
Files attached to this application
GCE-157-2026_Photos_GCE_Mesocosms.pptx (MS PowerPoint, 3424.17 kb, submitted 07/07/2026)
