Sapelo Research Application Form
Research Application ID: GCE-145-2025 (submitted: 05/21/2025, status: approved)
Provide a brief title for web display
Refuge value of slump blocks across a natural elevation gradient
Investigator Information
On Island Sponsor: GCE SINERR UGAMI GADNR
| Principal Investigator: | James Byers | ||
| Home Institution: | University of Georgia | ||
| Award Information: | NSF GRFP | ||
| Mailing Address: | Room 194B, Ecology Bldg. | Phone Number: | (706) 583-0012 |
| Odum School of Ecology | E-mail Address: | jebyers@uga.edu | |
| Athens, Georgia 30602 | |||
| Co-investigators: | Matthew Pierce (University of Georgia) | ||
Briefly describe the project goals and methodology
The goals of the project is to understand how vegetative structure effects snail survival at lower elevations in tidal creekbanks. Understanding these affects will allow us to better understand the refuge value of erosional slump blocks for prey species, such as the marsh periwinkle.
Within one tidal creek (Lighthouse Creek) on Sapelo Island, GA, I will set up two horizontal transects across one expansive mudflat. I will remove all Spartina alterniflora on the marsh edge behind the transect set up at the highest elevation of the mudflat (approximately 16 x 1 meters of S. alterniflora will be removed on the creekbank).Each transect will have 12 plots (either 0.5 x 0.5 m or 1x1 m) that will be randomly assigned a stem density(either stems present or absent) (Fig. 8). Stem structures will be made of either bamboo or cut S. alterniflora stalks (to be determined after field test). Elevation measurements will be taken at each plot and tide meters will be placed at each mudflat site to calculate inundation depth for each experimental trial. Each plot will have 5 to 10 tethered Littoraria irrorata snails distributed across the area of the plot. Predation will be quantified by collecting data on snail mortality (0=dead, 1=alive) and by calculating the proportion of snails consumed. Snail position or height on stalk will be measured for all surviving snails after each trial. Due to an expected prolonged setup time, I will have one mudflat site running with trials running for one complete tidal cycle (24 hours) for each of ~8-10 trials.
Before and after the predation trials the relative predator abundance (mainly blue crabs, Callinectus sapidus, and the mud crab, Panopeus spp.) will be quantified at each mudflat site. I will use baited traps placed in the open plots to quantify predation risk and identify possible predator species. Additionally, methods will be explored to track blue crab habitat preference during periods of high tide (Micheli 1997).
Where will the project be located?
Mud flat in Lighthouse Creek: 31°23'38.1"N 81°16'47.5"W
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: 05/26/2025 End Date: 07/31/2025
How many people will access the site and at what frequency?
3 people every day for three weeks.
Keywords that describe your project
What equipment will be deployed in the field?
Three water pressure gauges will be placed in pvc stakes (2-3 in diameter and 2 ft. long). Clear plastic tethers will be (120 or 240) will be placed across 24 plots (0.5x0.5 m or 1x1 m in the mudflat). One pvc flag will be placed in each plot for repeated measures.
Will plants or animals be collected as part of this study?
Yes, Spartina alterniflora stalks (240 to 360 stems) and 960 to 1920 L. irrorata snails will be collected and used. A UGAMI collection permit has been obtained for these collections.
What are the likely impacts of the project on the site?
Likely impacts include the clipping of Spartina alterniflora (16 x 1 meters will be clipped) along the creekbank just above the mud flat. PVC stakes will be put in for the duration of the experiment in the mud flat at transects and on the creekbank.
Will the project design include boardwalks? If not, explain why not.
How long will impacts persist after the research is concluded?
Impacts to the clipping and removal of Spartina are expected to last no longer than 6-12 months once the experiment has been completed. Spartina is known to regrow quickly if removed during the growing season, so no long term impacts are expected.
