PS 50-102
Potential for ghost crab predation on sea turtle nests on driving and non-driving beaches in St. Johns County, Florida

Wednesday, August 12, 2015
Exhibit Hall, Baltimore Convention Center
Alec Cronin, Doris Duke Conservation Scholars Program, University of Florida, Gainesville, FL
Adreenah Wynn, Doris Duke Conservation Scholars Program, University of Florida, Gainesville, FL
Brian J. Smith, Wildife Ecology & Conservation, University of Florida, Gainesville, FL
Nichole Bishop, School of Natural Resources & Environment, University of Florida, Gainesville, FL
Ray Carthy, FL Coop Fish and Wildlife Unit, University of Florida, Gainesville, FL
Background/Question/Methods

All species of marine turtle have experienced global declines, and five species of conservation concern nest on Florida beaches.  A controversial practice that potentially threatens nesting success and hatchling survival is that of vehicular beach traffic.  It has been posited that beach driving creates barriers (eg tire ruts) for hatchlings and compacts sand, disrupting gas exchange in the nest chamber.  However, beach driving has also been shown to deter the presence of ghost crabs, a major predator of sea turtle nests and hatchlings.  The purpose of this study was to compare the presence of ghost crab burrows in proximity to sea turtles nests on driving and non-driving beaches.  Nests were selected at random at each beach and the number of ghost crab burrows within the radius of maximum recorded burrow length was counted. 

Results/Conclusions

An independent t-test determined that driving beaches had significantly fewer ghost crab burrows within the specified radius (p=0.035) than non-driving beaches.  These preliminary results may indicate that beach driving could indirectly reduce ghost crab predation of sea turtles nests.  Further studies would be necessary to determine if the negative effects of beach driving outweigh the threat of ghost crab predation.
(DOI/USGS: IP-063750)