Meeting Abstract
Severe weather can have a drastic effect on salt marshes. Weather patterns that bring sudden, severe changes (storms, drought) can destabilize salt marsh ecosystems. Salt marshes act as flood barriers in the face of freak storms and flooding. Spartina alterniflora, a tall grass often found in salt marshes, is used as protection by fiddler crabs (Uca pugnax and U. pugilator) and as a cornerstone for mussels to build mounds. Mounds increase water holding capacity in salt marshes, play an important role in recovery from droughts, and offer protection and places to eat for fiddler crabs. Because of their position in the salt marsh food web, fiddler crab population reduction or local extinction would be detrimental to other species populations (e.g. birds, blue crabs, turtles and fish). The purpose of this study is to see whether proximity to creeks affect juvenile fiddler crab density and mound density at a salt marsh in Tybee Island, GA. Three locations near a creek (mid to low-marsh), away from the creek (high marsh), and across the street from the creek (high marsh) with three 10m x 10m plots along transect lines were setup. Spartina height, mound size frequency distribution and juvenile fiddler crab abundance were noted during the summer months. Preliminary measurements made at two of the three locations indicate significantly taller Spartina close to the creek (119.2 cm) than across the street (59.2 cm) and a mean of 9 mounds near the creek and 8 mounds across the street from the creek. There were significantly more large mussel mounds (> 3m2 in area) near the creek (3) than away from the creek (1). We believe there is a correlation between proximity to creeks, mussel mounds, and fiddler crab density. Severe weather and anthropogenic changes thus pose a significant threat to the health of Georgia’s salt marshes.
